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The Freescale Freedom KL26Z hardware (FRDM-KL26Z) is a capable and cost-effective design featuring a Kinetis L series microcontroller, the industry’s first microcontroller built on the ARM® Cortex™-M0+ core. It features a KL26Z128VLH4 (KL26Z), a device boasting a maximum operating frequency of 48MHz, 128KB of flash. The FRDM-KL26Z features the Freescale open standard embedded serial and debug adapter known as OpenSDA. You can find more information at following link: FRDM-KL26Z: Freescale Freedom Development Platform for Kinetis KL16 and KL26 MCUs (up to 128 KB Flash) The second required board for this example is the Freescale's Freedom Development Platform for Multiple Xtrinsic Sensors, the FRDM-FXS-MULTI. It is a sensor expansion board that contains 7 sensors among which is the FXAS21000 Xtrinsic 3-axis gyroscopic sensors. This example is using above mentioned tools to create data acquisition system (DAQ) for acquiring angular rate data measured in deg/s from the FXAS21000 Xtrinsic 3-axis gyroscopic sensors (Gyro). For data logging and visualization of acquired data FreeMASTER tool is used. The output is in 3 directions of rotation. Around X direction is for the Roll (around longitudinal axis), around Y direction is for the Pitch (around the lateral axis) and around Z direction for the Yaw (around the vertical axis). The Gyro embedded registers are accessed through an I 2 C serial interface and routed to KL26Z I 2 C 1 module with following pin association. Precisely the 7-bit I 2 C slave address is 0x20 (SA0=0) and SCL1, SDA1 lines are routed to port C of the I 2 C 1 module at KL26Z board pins PTC1 and PTC2: Proper interrupt INT1_GYRO at J1-6 needs to be routed via jumper on J6 to INT_GYRO as shown in following block diagram since the interrupts are shared with other sensors: This is then handled as GPIO port A: PTA at the KL26Z board and configured for the falling edge interrupts. For more details see the schematics of the FRDM-FXS-MULTI block diagram. This example illustrates:    1.  Initialization of the KL26Z MCU (I 2 C and PORT modules).    2. Initialization of the Gyro to achieve the resolution 0.025 dsp/LSB with +/-200 dps range and a high-pass filter on.    3. Output data reading using an interrupt technique.    4. Conversion of the output values from registers 0x01 – 0x06 to real values in deg/s.    5. Visualization of the output values in the FreeMASTER tool. 1. According to the schematic, the INT1_GYRO output of the FXAS21000 is connected to the PTA5 pin of the KL26Z MCU and both SCL and SDA lines are connected to the I2C1 module (PTC1 and PTC2 pins). The MCU is, therefore, configured as follows:      void MCU_Init(void){              //I2C1 module initialisation         SIM_SCGC4 |= SIM_SCGC4_I2C1_MASK;       // Turn on clock to I2C1 module         SIM_SCGC5 |= SIM_SCGC5_PORTC_MASK;      // Turn on clock to Port C module         PORTC_PCR1 = PORT_PCR_MUX(2);           // PTC1 pin is I2C1 SCL1 line pin alternative         PORTC_PCR2 = PORT_PCR_MUX(2);           // PTC2 pin is I2C1 SDA1 line pin alternative         I2C1_F = 0x14; // SDA hold time = 2.125us, SCL start hold time = 4.25us, SCL stop hold time = 5.125us         I2C1_C1 = I2C_C1_IICEN_MASK;                    // Enable I2C1 module              //Configure the PTA5 pin (connected to the INT_GYRO of the FXAS21000) for falling edge interrupts         SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;      // Turn on clock to Port A module         PORTA_PCR5 |= (0|PORT_PCR_ISF_MASK|     // Clear the interrupt flag         PORT_PCR_MUX(0x1)|                      // PTA5 is configured as GPIO         PORT_PCR_IRQC(0xA));                    // PTA5 is configured for falling edge interrupts             //Enable PORTA interrupt on NVIC         NVIC_ICPR |= 1 << ((INT_PORTA - 16)%32);         NVIC_ISER |= 1 << ((INT_PORTA - 16)%32);      } 2. At the beginning of the initialization, all Gyro registers are reset to their default values by setting the RST bit of the CTRL_REG1 register. Also the ZR_cond in CTRL_REG1 to trigger the offset compensation is enabled and hold till ZR_cond offset compensation is accomplished. This is meant to be used only when the IC is in zero rate condition on all axes. Writing a '1' to this bit initiates the internal zero-rate offset calibration. The ZR_cond bit self-clears after the zero-rate offset calculation, and it can only be used once after a hard or soft reset has occurred. The measuring range of Gyro is set to ±200 dps and to achieve the highest resolution the ODR = 1.5625Hz (640ms) and the High-pass filter is enabled with H-P filter cutoff frq.:0.047 Hz.      void Gyro_Init (void){              unsigned char reg_val = 0;          I2C_WriteRegister(FXAS21_I2C_ADDRESS, CTRL_REG1, 0x40); // Reset all registers to POR values              do              // Wait for the RST bit to clear              {                 reg_val = I2C_ReadRegister(FXAS21_I2C_ADDRESS, CTRL_REG1) & 0x40;              } while (reg_val);         // Zero values initialisation ------------------------------------------------------------             //      I2C_WriteRegister(FXAS21_I2C_ADDRESS, CTRL_REG1, 0x80); // ZR_cond to trigger offset compensation             do      // wait till ZR_cond to trigger offset compensation accomplished          {           reg_val = I2C_ReadRegister(FXAS21_I2C_ADDRESS, CTRL_REG1) & 0x80;               } while (reg_val);             //----------------------------------------------------------------------------------------         I2C_WriteRegister(FXAS21_I2C_ADDRESS, CTRL_REG2, 0x0C); // Enable DRDY interrupt, DRDY interrupt routed to INT1 - PTA5, Push-pull, active low interrupt         I2C_WriteRegister(FXAS21_I2C_ADDRESS, CTRL_REG0, 0x17); // High-pass filter enabled, H-P filter cutoff frq.:0.047 Hz, +/-200 dps range -> 0.025 dsp/LSB = 40 LSB/dps         I2C_WriteRegister(FXAS21_I2C_ADDRESS, CTRL_REG1, 0x1E); // ODR = 1.5625Hz(640ms), Active mode      }      Below are the snap shots of write and read section of the registers from the instructions above.           3. In the ISR, only the interrupt flag is cleared and the DataReady variable is set to indicate the arrival of new data.      void PORTA_IRQHandler(){         PORTA_PCR5 |= PORT_PCR_ISF_MASK;                        // Clear the interrupt flag         DataReady = 1;       }      4. The output values from Gyro registers 0x01 – 0x06 are first converted to signed 14-bit values and afterwards to real values in deg/s.      while(1){              if (DataReady){                 // Is a new set of data ready?                               DataReady = 0;                                                                                                I2C_ReadMultiRegisters(FXAS21_I2C_ADDRESS, OUT_X_MSB_REG, 6, GyrData);  // Read data output registers 0x01-0x06              Xout_14_bit = ((short) (GyrData[0]<<8 | GyrData[1])) >> 2;// Compute 14-bit X-axis output value      Yout_14_bit = ((short) (GyrData[2]<<8 | GyrData[3])) >> 2;// Compute 14-bit Y-axis output value              Zout_14_bit = ((short) (GyrData[4]<<8 | GyrData[5])) >> 2;// Compute 14-bit Z-axis output value                                        Roll = ((float) (Xout_14_bit)) / SENGYR_025D;   // Compute X-axis output value in dps              Pitch = ((float) (Yout_14_bit)) / SENGYR_025D;  // Compute Y-axis output value in dps              Yaw = ((float) (Zout_14_bit)) / SENGYR_025D;    // Compute Z-axis output value in dps                                    Temperature on the Gyro is also read out from the TEMP register of the Gyro              Temp = (signed char) I2C_ReadRegister(FXAS21_I2C_ADDRESS, TEMP_REG);  // temperature on Gyro      5. The calculated values can be watched in the "(x)= Variables" window on the top right of the Debug perspective of the CodeWarrior IDE or in the FreeMASTER application.      To open and run the FreeMASTER project, install the FreeMASTER 1.4 application and FreeMASTER Communication Driver that can be downloaded from following link:      FREEMASTER: FreeMASTER Run-Time Debugging Tool      User Guide for FreeMASTER is available within the installation.      For board communication in FreeMASTER following Options of Plug-in Module needs to be selected and configured for the BDM P&E Kinetis cable settings:             FreeMASTER in action screenshot: Enjoy the Freescale Gyro.
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Hello Freescale Community, Most of the new Freescale Sensors in our portfolio come in very small packages, some of them as small as 2x2x1mm, which is awesome! However, one of the problems that we detected last year is that many customers struggle in the evaluation stage of the project due to the small packages. They should either, buy an evaluation board or spend valuable time designing and manufacturing a PCB just for testing our devices. Our goal with this project is to share with our community the Freescale Sensors Breakout Boards we designed for this specific purpose, so you can easily manufacture your own sensor boards or modify our designs to fit  your specific application. This way you can easily evaluate Freescale sensors. The boards were designed to be used in a prototype board (DIP style pins) and they can communicate to any MCU thru IIC or SPI (depending on the sensor). These designs were made using Eagle Layout 6.5, if you want to modify the designs you can do it with the free version of Eagle CAD (for non-commercial purposes), or you can send the gerber files (included in the zip files) to your preferred PCB manufacturer. The following designs are available: + Altimeter: MPL3115A2 Breakout Board + Accelerometer: MMA845x Breakout Board MMA865x Breakout Board MMA8491 Breakout Board FXLN83xx Breakout Board FXLS8471 Breakout Board MMA690x Breakout Board + Accelerometer + Magnetometer (6-DOF): FXOS8700 Breakout Board + Gyroscope: FXAS2100x Breakout Board The above .ZIP files, contains the following design information: - Schematic Source File (.SCH) - Schematic (.PDF) - Layout Source File (.BRD) - Layout Images (.jpg) - Gerber Files (GTL, GBL, GTS, GBS, GTO, GBO, GKO, XLN). - PCB Render Image (.png created in OSH park) - BOM (.xls) Additional content: If you want to modify our designs, please download the attached library file "Freescale_Sensors_v2.lbr" and add it to your Eagle Library repository. We'll be more than glad to respond to your questions and please, let us know what you think. -Freescale Sensor's Support team.
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Freescale’s FXOS8700CQ 6-axis sensor combines industry leading accelerometer and magnetometer sensors in a small 3 x 3 x 1.2 mm QFN plastic package. The 14-bit accelerometer and 16-bit magnetometer are combined with a high-performance ASIC to enable an eCompass solution capable of a typical orientation resolution of 0.1 degrees and sub 5 degree compass heading accuracy for most applications. Applications include eCompass, enhanced user interface, augmented reality, and location based services (static geographic heading). Target products include smartphones, tablets, personal navigation devices, remote controls for smart TV’s, watches, gaming controllers, robotics, and unmanned air vehicles (UAVs). Here is a Render of the FXOS8700 Breakout- Board downloaded from OSH Park: And here is an image of the Layout Design for this board: In the Attachments section, you can find the Schematic Source File (.SCH), Schematic PDF File, Layout Source File (BRD), Gerber Files (GTL, GBL, GTS, GBS, GTO, GBO, GKO, XLN) and BOM for this Breakout-board. If you are interested in more designs like this breakout board for other sensors, please go to Freescale Sensors Breakout Boards Designs – HOME
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Hi Folks, Due to a very high number of questions from our customers regarding how to select the proper Freescale Pressure Sensor for their applications I have decided to create this illustrated, step-by-step easy to follow guideline about how to do it by yourself. Step 1: Go to http://www.freescale.com/webapp/parametricSelector.sp Then click on “Pressure Sensors” Now you should see the following window: And at this point everything is intuitive and basically the rest for select the proper Freescale Pressure Sensor depends on the requirements of your application. However, in order to trying to give you a better explanation, I’m doing an example: For this example let assume that my application requirements are as follow: Pressure measurement range up to 100kPa (higher priority parametric search for my app) Absolute Pressure Sensor Analog Output Integrated Side Ported Mount surface Package: SOP 8 (*I added the “Package Type” Parametric Search) (lower priority) *You can add or remove search parameters clicking on the “Show/Hide Parameters” button.  Based on the mentioned requirements, I selected the check boxes on the Parametric Search Window starting from the parametric with higher priority and leaving the parametric with lower priority at the end, and as a result I will get something like the image below: * You can leave unselected check boxes if are not important for your application, for my example from the image above I leave the “Ambient Operating Temperature” option unselected. So, from the initial 37 pressure sensors options I have to select, now the list it’s reduced to only 1 option, so, for this particular example, the MPXV5100 is the best solution for my application. If there are any questions regarding this guideline, please feel free to ask below. Your feedback or suggestions are also welcome. Regards, Jose
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Current errata for ISF 2.1
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The Freedom Sensor Toolbox-Community Edition GUI (Graphic User Interface) offers quick and easy demonstration and evaluation of the NXP sensors. The GUI can be downloaded from this link: https://www.nxp.com/design/software/development-software/sensor-toolbox-sensor-development-ecosystem/freedom-sensor-toolbox-community-edition-sensor-evaluation-and-visualization-software:SENSOR-TOOLBOX-CE NXP sensor demonstration kits compatible with the GUI are available at this link: https://www.nxp.com/design/sensor-developer-resources/sensor-toolbox-sensor-development-ecosystem/evaluation-boards:SNSTOOLBOX?tid=vanSENSOREVALUATIONBOARDS There is an User Guide available, for the Freedom Sensor Toolbox-Community Edition GUI, describing installation, running and also troubleshooting of some common problems with the GUI. Please find the User Guide at this link: https://www.nxp.com/docs/en/user-guide/STBCEUG.pdf   Figure 1. The Freedom Sensor Toolbox GUI is running correctly, Main Page When the toolbox is running correctly, after pressing the Stat button, user can observe change in individual axis in the plot,  according to the change of the individual axis on the sensor evaluated. See Figure 1. for an example with the MMA8652 accelerometer.  Note the green mark in the right down corner indicating, that the GUI and kit is working correctly. User can also observe change in Parameter Details in the Register page. See Figure 2.   Figure 2. The Freedom Sensor Toolbox GUI  is running correctly, Register Page Some users might come across an issue, where after pressing the start button, the plot in the Main Page of the Toolbox shows only zeroes for all three axis, no matter how the tilt for any of the axis, of the evaluated sensor changes. See Figure 3. Note the red exclamation mark in the right down corner, indicating an issue with the GUI. Although the Parameter Details in the Register Page shows correct values according the change of individual axis on the evaluated sensor. See Figure 4.   Figure 3. Plot in the Main Page of the GUI shows only zeroes for all three axis   Figure 4. Parameter Details in the Register Page of the GUI The issue with the wrong scaling in the Freedom Sensor Toolbox-Community Edition GUI is linked to the local preference and format on the computer. The GUIs have been designed in Chandler/USA where decimal symbol is a simple point. In Europe and in some Asian countries, it is usually a comma, hence this can cause issue with the plot. The workaround to fix the issue with the unresponsive plot in the Main Page of the GUI is to change the decimal point in Windows operational system from comma to point. Follow the instructions according the following Figures.   Figure 5. In Start menu press the Settings button   Figure 6. In the Windows Settings choose Time & Language   Figure 7. In the Time & Language window choose Region following with Additional date, time & regional settings   Figure 8. In the Clock and Region choose Change date, time or number formats   Figure 9. In Region window press Additional settings   Figure 10. In the Customize Format window change the Decimal symbol to point After changing the Decimal symbol to point, simply turn on the Freedom Sensor Toolbox GUI and the plot will show changes in the individual axis according to the change in tilt of the sensor for individual axis.
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This is a PDF version of the Sensor Fusion tutorial I gave at the RoboBusiness conference in Santa Clara on 24 October.
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The FXLS8471Q Freescale accelerometer is highly versatile for industrial and consumer high-performance low-g applications that offer noise density, board mount offset, temperature performance and sensitivity. Integrated motion detection features include tilt, shake and tap detection with a new vector magnitude output that simplifies implementation and reduces power consumption. This new FXLS8471Q accelerometer has a SPI interface that is pin-compatible with Freescale’s industry-leading I2C accelerometer portfolio. Here is a Render of the FXLS8471 Breakout- Board downloaded from OSH Park: And here is an image of the Layout Design for this board: In the Attachments section, you can find the Schematic Source File (.SCH), Schematic PDF File, Layout Source File (BRD), Gerber Files (GTL, GBL, GTS, GBS, GTO, GBO, GKO, XLN) and BOM for this Breakout-board. If you are interested in more designs like this breakout board for other sensors, please go to Freescale Sensors Breakout Boards Designs – HOME
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         The FXTH87XXX is a sensor for use in applications that monitor tire pressure and temperature. It contains the pressure and temperature sensors, an X-axis and a Z-axis accelerometer, a microcontroller, an LF receiver and an RF transmitter all within a single package.          NCK2912 is a fully integrated single-chip receiver for use in an automotive environment. The device incorporated several commonly used building blocks including a crystal stabilized oscillator, a fractional-N based Phase Locked Loop(PLL) for a accurate frequency selection, Low Noise Amplifier(LNA), attenuator for Automatic Gain Control(AGC), I/Q down-mixer and two high resolution Analog to Digital Converters(ADC). By transforming signals in the digital domain in an early phase, one highly configurable RX channel is available including channel filter, ASK/FSK demodulator, clock-data recovery, bit processor and a micro-controller memory interface(DMA) allowing the micro-controller to complete the data handling and handshaking. NCK2912 has an embedded RISC micro-controller optimized for high performance and low power as well as an EROM for customer application.         
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Hi Everyone,   In this document I would like to present a simple bare-metal example code/demo for the FXLN8371Q Xtrinsic three axis, low-power, low-g, analog output accelerometer. I have created it while working with the Freescale FRDM-KL25Z development platform and FXLN8371Q breakout board. The FreeMASTER tool is used to visualize the acceleration data that are read from the FXLN8371Q through ADC.   This example illustrates:   1. Initialization of the MKL25Z128 MCU (mainly ADC, PORT and PIT modules). 2. Simple offset calibration. 3. Accelerometer outputs reading using ADC and conversion of the 10-bit ADC values to real acceleration values in g’s. 4. Visualization of the output values in the FreeMASTER tool.   1. The FXLN8371Q breakout board (schematic is attached below) needs to have the following pins connected to the FRDM-KL25Z board:   J4-1 (VDD) => J9-4 (P3V3) J4-2 (XOUT) => J10-2 (PTB0/ADC0_SE8) J4-3 (YOUT) => J10-4 (PTB1/ADC0_SE9) J4-4 (ZOUT) => J10-6 (PTB2/ ADC0_SE12) J4-6 (GND) => J9-14 (GND) J3-3 (ST) => J9-14 (GND) J3-4 (EN) => J9-4 (P3V3)   The PIT (Periodic Interrupt Timer) is used to read the output data periodically at a fixed rate of ~200Hz. The MCU is, therefore, configured as follows.   void MCU_Init(void) {      //ADC0 module initialization      SIM_SCGC6 |= SIM_SCGC6_ADC0_MASK;        // Turn on clock to ADC0 module      SIM_SCGC5 |= SIM_SCGC5_PORTB_MASK;       // Turn on clock to Port B module      PORTB_PCR0 |= PORT_PCR_MUX(0x00);        // PTB0 pin is ADC0 SE8 input      PORTB_PCR1 |= PORT_PCR_MUX(0x00);        // PTB1 pin is ADC0 SE9 input      PORTB_PCR2 |= PORT_PCR_MUX(0x00);        // PTB2 pin is ADC0 SE12 input      ADC0_CFG1 |= ADC_CFG1_ADLSMP_MASK | ADC_CFG1_MODE(0x02);             // Long sample time, single-ended 10-bit conversion                           //PIT module initialization      SIM_SCGC6 |= SIM_SCGC6_PIT_MASK;         // Turn on clock to PIT module      PIT_LDVAL0 = 52400;                      // Timeout period = ~5ms (200Hz)      PIT_MCR = PIT_MCR_FRZ_MASK;              // Enable clock for PIT, freeze PIT in debug mode                               //Enable PIT interrupt on NVIC          NVIC_ICPR |= 1 << ((INT_PIT - 16) % 32);      NVIC_ISER |= 1 << ((INT_PIT - 16) % 32); }   2. The simplest offset calibration method consists of placing the board on a flat surface so that X is at 0g, Y is at 0g and Z is at +1g. 16 samples are recorded and then averaged. The known sensitivity needs to be subtracted from the +1g reading to calculate an assumed 0g offset value for Z.   void Calibrate(void) {      unsigned int Count = 0;                    do                   // Accumulate 16 samples for X, Y, Z      {         ADC0_SC1A = ADC_SC1_ADCH(0x08);               // Process ADC measurements on ADC0_SE8/XOUT                                                                while(!(ADC0_SC1A & ADC_SC1_COCO_MASK)){};         Xout_10_bit += ADC0_RA;                                                                                                      ADC0_SC1A = ADC_SC1_ADCH(0x09);               // Process ADC measurements on ADC0_SE9/YOUT                while(!(ADC0_SC1A & ADC_SC1_COCO_MASK)){};         Yout_10_bit += ADC0_RA;                                                                                                            ADC0_SC1A = ADC_SC1_ADCH(0x0C);                while(!(ADC0_SC1A & ADC_SC1_COCO_MASK)){};    // Process ADC measurements on ADC0_SE12/ZOUT               Zout_10_bit += ADC0_RA;                                                         Count++;                        } while (Count < 16);                    X_offset = (float) Xout_10_bit / 16;                             // Compute X-axis offset by averaging all 16 X-axis samples      Y_offset = (float) Yout_10_bit / 16;                             // Compute Y-axis offset by averaging all 16 Y-axis samples      Z_offset = ((float) Zout_10_bit / 16) - SENSITIVITY_2G;          // Compute Z-axis offset by averaging all 16 Z-axis samples and subtracting the known sensitivity                      PIT_TCTRL0 = PIT_TCTRL_TIE_MASK | PIT_TCTRL_TEN_MASK;          // Enable PIT interrupt and PIT                                      }   3. Reading the FXLN8371Q datasheet, the output voltage when there is no acceleration is typically 0.75V and it should typically change by 229mV per 1g of acceleration in ±2g mode. The signal from a 10-bit ADC gives me a number from 0 to 1023. I will call these “ADC units”.  0V maps to 0 ADC units, VDDA (2.95V on the FRDM-KL25Z board) maps to 1023 ADC units and let’s assume it is linear in between. This means that zero acceleration on an axis should give me a reading of 260 ADC units (0.75V / 2.95V x 1023 ADC units) on the pin for that axis. Also, a change of 1 ADC unit corresponds to a voltage difference of 2.95V / 1023 ADC units = 2.884mV/ADC unit. Since the datasheet says a 1g acceleration typically corresponds to 229mV voltage difference, I can easily convert it to ADC units/g:   229 mV/g = 229 mV/g x (1023 ADC units) / 2.95V = 79.4 ADC units/g = SENSITIVITY_2g   Using this calculated sensitivity and measured offset, I convert the 10-bit ADC values to real acceleration values in g’s in the PIT ISR as follows.   void PIT_IRQHandler() {      ADC0_SC1A = ADC_SC1_ADCH(0x08);                    // Process ADC measurements on ADC0_SE8/XOUT                                                  while(!(ADC0_SC1A & ADC_SC1_COCO_MASK)){};      Xout_10_bit = ADC0_RA;                                         ADC0_SC1A = ADC_SC1_ADCH(0x09);                    // Process ADC measurements on ADC0_SE9/YOUT                while(!(ADC0_SC1A & ADC_SC1_COCO_MASK)){};      Yout_10_bit = ADC0_RA;                                               ADC0_SC1A = ADC_SC1_ADCH(0x0C);                    // Process ADC measurements on ADC0_SE12/ZOUT                while(!(ADC0_SC1A & ADC_SC1_COCO_MASK)){};      Zout_10_bit = ADC0_RA;                    Xout_g = ((float) Xout_10_bit - X_offset) / SENSITIVITY_2G;         // Compute X-axis output value in g's      Yout_g = ((float) Yout_10_bit - Y_offset) / SENSITIVITY_2G;         // Compute Y-axis output value in g's      Zout_g = ((float) Zout_10_bit - Z_offset) / SENSITIVITY_2G;         // Compute Z-axis output value in g's                     PIT_TFLG0 |= PIT_TFLG_TIF_MASK;          // Clear PIT interrupt flag }   4. The calculated values can be watched in the "Variables" window on the top right of the Debug perspective or in the FreeMASTER application. To open and run the FreeMASTER project, install the FreeMASTER application and FreeMASTER Communication Driver.       I guess this is enough to let you start experimenting with the FXLN83xxQ family of analog accelerometers. Attached you can find the complete source code written in the CW for MCU's v10.6 including the FreeMASTER project.   If there are any questions regarding this simple application, do not hesitate to ask below. Your feedback or suggestions are also welcome.   Regards, Tomas Original Attachment has been moved to: FRDM-KL25Z-FXLN8371Q-Basic-read-using-ADC.zip Original Attachment has been moved to: FreeMASTER---FRDM-KL25Z-FXLN8371Q-Basic-read-using-ADC.zip
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SOP Top Side Port Package_1369-01  
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Hands-on Training using Sensors Development Ecosystem
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Hi Everyone,   In this document I would like to present a very simple bare-metal example code I created for the LM75A. This I 2 C digital temperature sensor offers an improved resolution of 0.125°C with an accuracy of ±2°C from –25°C to 100°C and ±3°C over –55°C to 125°C. It operates with a single supply from 2.8V to 5.5V and has three address pins, allowing up to eight LM75A devices to operate on a single I 2 C bus without address collisions. The device also includes an open-drain output (OS) which becomes active when the temperature exceeds the programmed limits.   NXP offers the OM13257 temperature sensor daughter card for easy evaluation of most NXP’s temperature sensors including the LM75ADP in a small 8-pin TSSOP8 package. The daughter card is shipped with no temperature sensors soldered to the board, so the LM75ADP needs to be purchased and soldered separately. The daughter board is designed to connect directly to the OM13320 Fm+ Development kit, but I have decided to pair it with one of the most popular Freedom development boards – FRDM-KL25Z.   The wiring is very straightforward as shown on the picture below. Both SCL (JP4-2) and SDA (JP3-2) lines are connected through the on-board 10K pull-up resistors to the I2C1 module (PTE1 and PTE0 pins) on the KL25Z128 MCU. The Vcc pin (JP2-2) is connected to the 3.3V supply voltage and the GND pin to common ground. The address select pins A2, A1 and A0 are connected to GND using jumpers between pins 1 and 2 of JP12, JP11 and JP10, resulting in a 7-bit I 2 C slave address of 0x48.       The LM75A does not have a data ready interrupt, so the PIT (Periodic Interrupt Timer) module is used to read the Temp register periodically at a fixed rate of about 10Hz since the temp-to-digital conversion is executed every 100 ms. The MCU is configured as follows.   /************* MCU initialization function ******/   void MCU_Init(void) {   //I2C1 module initialization SIM_SCGC4 |= SIM_SCGC4_I2C1_MASK; // Turn on clock to I2C1 module  SIM_SCGC5 |= SIM_SCGC5_PORTE_MASK; // Turn on clock to Port E module  PORTE_PCR1 |= PORT_PCR_MUX(6); // PTE1 pin is I2C1 SCL line PORTE_PCR0 |= PORT_PCR_MUX(6); // PTE0 pin is I2C1 SDA line I2C1_F  |= I2C_F_ICR(0x14); // SDA hold time = 2.125us, SCL start hold time = 4.25us, SCL stop hold time = 5.125us   I2C1_C1 |= I2C_C1_IICEN_MASK; // Enable I2C1 module     //PIT initialization    SIM_SCGC6 |= SIM_SCGC6_PIT_MASK; // Turn on clock to to the PIT module   PIT_LDVAL0 = 1048000; // Timeout period = 100 ms   PIT_MCR = PIT_MCR_FRZ_MASK; // Enable clock for PIT, freeze PIT in debug mode PIT_TCTRL0 = PIT_TCTRL_TIE_MASK | // Enable PIT interrupt   PIT_TCTRL_TEN_MASK; // and PIT     //Enable PIT interrupt on NVIC NVIC_ICPR |= 1 << ((INT_PIT - 16) % 32); NVIC_ISER |= 1 << ((INT_PIT - 16) % 32); }       In the PIT ISR, the Temp register is read and then the real temperature in °C is calculated as shown below. For more information on how to convert the raw values from the Temp register to real values in °C, please refer to the LM75A data sheet (chapter 7.4.3).   /******** Interrupt handler for PIT ************/   void PIT_IRQHandler() {   PIT_TFLG0 |= PIT_TFLG_TIF_MASK; // Clear the PIT interrupt flag I2C_ReadMultiRegisters(LM75A_I2C_ADDRESS, TEMP_REG, 2, TemperatureData); // Read LM75A Temperature register (MSB + LSB)    Temperature_11_bit = ((short) (TemperatureData[0]<<8 | TemperatureData[1])) >> 5; // Compute 11-bit temperature output value   Temperature = ((float) Temperature_11_bit) * 0.125; // Compute temperature in °C }       The screenshot below shows the two bytes read of the Temp register. It also illustrates how the OS output is activated in interrupt mode by crossing the Tos threshold value stored in the Tos register. The threshold value was set to 26°C, which corresponds to 16-bit value of 0x1A00 read out of the Temp register.       The calculated temperature can be watched in the "Variables" window on the top right of the Debug perspective or in the FreeMASTER application. To open and run the FreeMASTER project, install the FreeMASTER 2.0 application and FreeMASTER Communication Driver. You can try touching your finger to the sensor to see the temperature rise.         Attached you can find the complete source code written in the CW for MCU's v10.6 including the FreeMASTER project.   If there are any questions regarding this simple application, please feel free to ask below. Your feedback or suggestions are also welcome.   Regards, Tomas Original Attachment has been moved to: FreeMASTER---FRDM-KL25Z-LM75A-Temperature-reading-using-I2C.rar Original Attachment has been moved to: FRDM-KL25Z-LM75A-Temperature-reading-using-I2C.rar
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Hi Everyone,   If you are interested in a simple bare metal example code illustrating the use of the magnetic threshold detection function, please find below one of my examples I created for the FXOS8700CQ while working with the NXP FRDM-KL25Z platform and FRDM-FXS-MULT2-B sensor expansion board.   The FXOS8700CQ is set to detect magnetic field exceeding 12.8uT (128 counts) for a minimum period of 100ms on the X-axis. Once an event is triggered, an active low interrupt will be generated on the INT1 pin:   void FXOS8700CQ_Init (void) { I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, M_THS_X_MSB_REG, 0x00); // Threshold value MSB I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, M_THS_X_LSB_REG, 0x80); // Threshold value LSB I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, M_THS_CFG_REG, 0xCB); // Event flag latch enabled, logic OR of enabled axes, only X-axis enabled, threshold interrupt enabled and routed to INT1 I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, M_THS_COUNT_REG, 0x0A); // 100ms at 100Hz ODR and magnetometer mode only I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, M_CTRL_REG1, 0x1D); // Max OSR, only magnetometer is active I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG3, 0x00); // Push-pull, active low interrupt I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG1, 0x19); // ODR = 100Hz, Active mode }‍‍‍‍‍‍‍‍‍‍     In the ISR, only the interrupt flag is cleared and the M_THS_SRC (0x53) register is read in order to clear the SRC_M_THS flag in the M_INT_SRC register and deassert the INT1 pin, as shown on the screenshot below.   void PORTD_IRQHandler() { PORTD_PCR4 |= PORT_PCR_ISF_MASK; // Clear the interrupt flag M_Ths_src=I2C_ReadRegister(FXOS8700CQ_I2C_ADDRESS, M_THS_SRC_REG); // Read the M_THS_SRC register to clear the SRC_M_THS flag in the M_INT_SRC register and deassert the INT1 pin Event_Counter++; }‍‍‍‍‍‍       Attached you can find the complete source code. If there are any questions regarding this simple example code, please feel free to ask below.    Regards, Tomas
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Hi Everyone, In this tutorial I intend to run through my simple bare metal example code I created for the Freescale FRDM-KL25Z platform and the FRDM-STBC-AGM01 board containing a three axis accelerometer + magnetometer (FXOS8700CQ) and a three axis gyroscope (FXAS21002C). I will not cover the Sensor Fusion library and the ISF which also support this board. The FreeMASTER tool is used to visualize all the data that are read from both sensors using an interrupt technique through the I 2 C interface. This example illustrates: 1. Initialization of the MKL25Z128 MCU (mainly I 2 C and PORT modules). 2. I 2 C data write and read operations. 3. Initialization of the FXOS8700CQ and FXAS21002C. 4. Simple accelerometer offset calibration based on the AN4069. 5. Output data reading using an interrupt technique. 6. Conversion of the output raw values to real values in g’s, µT, dps and °C. 7. Visualization of the calculated values in the FreeMASTER tool. 1. As you can see in the FRDM-STBC-AGM01 schematic, both sensors are controlled via I 2 C by default. With jumpers J6 and J7 in their default position (2-3), the I 2 C signals are routed to the I2C1 module (PTC1 and PTC2 pins) of the KL25Z MCU. The INT1_8700 output is connected to the PTD4 pin and the INT1_21002 pin to the PTA5 pin of the KL25Z MCU. These both interrupt pins are configured as push-pull active-low outputs, so the corresponding PTD4/PTA5 pin configuration is GPIO with an interrupt on falling edge. The MCU is, therefore, configured as follows. void MCU_Init(void) {      //I2C1 module initialization      SIM_SCGC4 |= SIM_SCGC4_I2C1_MASK;        // Turn on clock to I2C1 module      SIM_SCGC5 |= SIM_SCGC5_PORTC_MASK;       // Turn on clock to Port C module      PORTC_PCR1 |= PORT_PCR_MUX(0x2);         // PTC1 pin is I2C1 SCL line      PORTC_PCR2 |= PORT_PCR_MUX(0x2);         // PTC2 pin is I2C1 SDA line      I2C1_F  |= I2C_F_ICR(0x14);              // SDA hold time = 2.125us, SCL start hold time = 4.25us, SCL stop hold time = 5.125us      I2C1_C1 |= I2C_C1_IICEN_MASK;            // Enable I2C1 module                       //Configure the PTD4 pin (connected to the INT1 of the FXOS8700CQ) for falling edge interrupts      SIM_SCGC5 |= SIM_SCGC5_PORTD_MASK;       // Turn on clock to Port D module      PORTD_PCR4 |= (0|PORT_PCR_ISF_MASK|      // Clear the interrupt flag                       PORT_PCR_MUX(0x1)|      // PTD4 is configured as GPIO                       PORT_PCR_IRQC(0xA));    // PTD4 is configured for falling edge interrupts                   //Configure the PTA5 pin (connected to the INT1 of the FXAS21002) for falling edge interrupts      SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;       // Turn on clock to Port A module      PORTA_PCR5 |= (0|PORT_PCR_ISF_MASK|      // Clear the interrupt flag                       PORT_PCR_MUX(0x1)|      // PTA5 is configured as GPIO                       PORT_PCR_IRQC(0xA));    // PTA5 is configured for falling edge interrupts                          //Enable PORTD interrupt on NVIC      NVIC_ICPR |= 1 << ((INT_PORTD - 16)%32);      NVIC_ISER |= 1 << ((INT_PORTD - 16)%32);                //Enable PORTA interrupt on NVIC      NVIC_ICPR |= 1 << ((INT_PORTA - 16)%32);      NVIC_ISER |= 1 << ((INT_PORTA - 16)%32); } 2. The 7-bit I 2 C slave address of the FXOS8700CQ is 0x1E since both SA0 and SA1 pins are shorted to GND. The address of the FXAS21002C is 0x20 since SA0 pin is also shorted to GND. The two screenshots below show the write operation which writes the value 0x25 to the CTRL_REG1 (0x2A) of the FXOS8700CQ and 0x16 to the CTRL_REG1 (0x13) of the FXAS21002C. Here is the single byte read from the WHO_AM_I register. As you can see, it returns the correct value 0xC7 for the FXOS8700CQ and 0xD7 for the FXAS21002C. Finally, a burst read of 12 bytes from the FXOS8700CQ output data registers (0x01 – 0x06 and 0x33 – 0x38) and 6 bytes from the FXAS21002C output data registers (0x01 – 0x06) is shown below. 3. At the beginning of the initialization, all registers are reset to their default values by setting the RST bit of the CTRL_REG2 register. Then the FXOS8700CQ is initialized as shown below. void FXOS8700CQ_Init (void) {      I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG2, 0x40);          // Reset all registers to POR values      Pause(0x631);          // ~1ms delay            I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, XYZ_DATA_CFG_REG, 0x00);   // +/-2g range with 0.244mg/LSB              I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, M_CTRL_REG1, 0x1F);        // Hybrid mode (accelerometer + magnetometer), max OSR      I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, M_CTRL_REG2, 0x20);        // M_OUT_X_MSB register 0x33 follows the OUT_Z_LSB register 0x06 (burst read)                       I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG2, 0x02);          // High Resolution mode      I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG3, 0x00);          // Push-pull, active low interrupt      I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG4, 0x01);          // Enable DRDY interrupt      I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG5, 0x01);          // DRDY interrupt routed to INT1 - PTD4      I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG1, 0x25);          // ODR = 25Hz, Reduced noise, Active mode   } And here is the initialization of the FXAS21002C. void FXAS21002C_Init (void) {      I2C_WriteRegister(FXAS21002C_I2C_ADDRESS, GYRO_CTRL_REG1, 0x40);     // Reset all registers to POR values      Pause(0x631);        // ~1ms delay            I2C_WriteRegister(FXAS21002C_I2C_ADDRESS, GYRO_CTRL_REG0, 0x03);     // High-pass filter disabled, +/-250 dps range -> 7.8125 mdps/LSB = 128 LSB/dps      I2C_WriteRegister(FXAS21002C_I2C_ADDRESS, GYRO_CTRL_REG2, 0x0C);     // Enable DRDY interrupt, routed to INT1 - PTA5, push-pull, active low interrupt      I2C_WriteRegister(FXAS21002C_I2C_ADDRESS, GYRO_CTRL_REG1, 0x16);     // ODR = 25Hz, Active mode        } 4. A simple accelerometer offset calibration method is implemented according to the AN4069. void FXOS8700CQ_Accel_Calibration (void) {      char X_Accel_offset, Y_Accel_offset, Z_Accel_offset;            FXOS8700CQ_DataReady = 0;           while (!FXOS8700CQ_DataReady){}           // Is a first set of data ready?      FXOS8700CQ_DataReady = 0;            I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG1, 0x00);          // Standby mode                 I2C_ReadMultiRegisters(FXOS8700CQ_I2C_ADDRESS, OUT_X_MSB_REG, 6, AccelMagData);          // Read data output registers 0x01-0x06                     Xout_Accel_14_bit = ((short) (AccelMagData[0]<<8 | AccelMagData[1])) >> 2;          // Compute 14-bit X-axis acceleration output value      Yout_Accel_14_bit = ((short) (AccelMagData[2]<<8 | AccelMagData[3])) >> 2;          // Compute 14-bit Y-axis acceleration output value      Zout_Accel_14_bit = ((short) (AccelMagData[4]<<8 | AccelMagData[5])) >> 2;          // Compute 14-bit Z-axis acceleration output value                   X_Accel_offset = Xout_Accel_14_bit / 8 * (-1);          // Compute X-axis offset correction value      Y_Accel_offset = Yout_Accel_14_bit / 8 * (-1);          // Compute Y-axis offset correction value      Z_Accel_offset = (Zout_Accel_14_bit - SENSITIVITY_2G) / 8 * (-1);          // Compute Z-axis offset correction value                   I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, OFF_X_REG, X_Accel_offset);                  I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, OFF_Y_REG, Y_Accel_offset);           I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, OFF_Z_REG, Z_Accel_offset);                        I2C_WriteRegister(FXOS8700CQ_I2C_ADDRESS, CTRL_REG1, 0x25);          // Active mode again } 5. In the ISRs, only the interrupt flags are cleared and the DataReady variables are set to indicate the arrival of new data. void PORTD_IRQHandler() {      PORTD_PCR4 |= PORT_PCR_ISF_MASK;          // Clear the interrupt flag      FXOS8700CQ_DataReady = 1;  } void PORTA_IRQHandler() {      PORTA_PCR5 |= PORT_PCR_ISF_MASK;          // Clear the interrupt flag      FXAS21002C_DataReady = 1;  } 6. The output values from accelerometer registers 0x01 – 0x06 are first converted to signed 14-bit integer values and afterwards to real values in g’s. Similarly, the output values from magnetometer registers 0x33 – 0x38 are first converted to signed 16-bit integer values and afterwards to real values in microtesla (µT). if (FXOS8700CQ_DataReady)          // Is a new set of accel + mag data ready? {                  FXOS8700CQ_DataReady = 0;                                                                                                                          I2C_ReadMultiRegisters(FXOS8700CQ_I2C_ADDRESS, OUT_X_MSB_REG, 12, AccelMagData);         // Read FXOS8700CQ data output registers 0x01-0x06 and 0x33 - 0x38                     // 14-bit accelerometer data      Xout_Accel_14_bit = ((short) (AccelMagData[0]<<8 | AccelMagData[1])) >> 2;        // Compute 14-bit X-axis acceleration output value      Yout_Accel_14_bit = ((short) (AccelMagData[2]<<8 | AccelMagData[3])) >> 2;        // Compute 14-bit Y-axis acceleration output value      Zout_Accel_14_bit = ((short) (AccelMagData[4]<<8 | AccelMagData[5])) >> 2;        // Compute 14-bit Z-axis acceleration output value                              // Accelerometer data converted to g's      Xout_g = ((float) Xout_Accel_14_bit) / SENSITIVITY_2G;        // Compute X-axis output value in g's      Yout_g = ((float) Yout_Accel_14_bit) / SENSITIVITY_2G;        // Compute Y-axis output value in g's      Zout_g = ((float) Zout_Accel_14_bit) / SENSITIVITY_2G;        // Compute Z-axis output value in g's                               // 16-bit magnetometer data                   Xout_Mag_16_bit = (short) (AccelMagData[6]<<8 | AccelMagData[7]);          // Compute 16-bit X-axis magnetic output value      Yout_Mag_16_bit = (short) (AccelMagData[8]<<8 | AccelMagData[9]);          // Compute 16-bit Y-axis magnetic output value      Zout_Mag_16_bit = (short) (AccelMagData[10]<<8 | AccelMagData[11]);        // Compute 16-bit Z-axis magnetic output value                                                         // Magnetometer data converted to microteslas      Xout_uT = (float) (Xout_Mag_16_bit) / SENSITIVITY_MAG;        // Compute X-axis output magnetic value in uT      Yout_uT = (float) (Yout_Mag_16_bit) / SENSITIVITY_MAG;        // Compute Y-axis output magnetic value in uT      Zout_uT = (float) (Zout_Mag_16_bit) / SENSITIVITY_MAG;        // Compute Z-axis output magnetic value in uT              } Similarly, the output values from gyroscope registers 0x01 – 0x06 are first converted to signed 16-bit integer values and afterwards to real values in degrees per second. Temperature is also read out from the 0x12 register. if (FXAS21002C_DataReady)         // Is a new set of gyro data ready? {                  FXAS21002C_DataReady = 0;                                                                                                                                       I2C_ReadMultiRegisters(FXAS21002C_I2C_ADDRESS, GYRO_OUT_X_MSB_REG, 6, GyroData);         // Read FXAS21002C data output registers 0x01-0x06                                   // 16-bit gyro data      Xout_Gyro_16_bit = (short) (GyroData[0]<<8 | GyroData[1]);           // Compute 16-bit X-axis output value      Yout_Gyro_16_bit = (short) (GyroData[2]<<8 | GyroData[3]);           // Compute 16-bit Y-axis output value      Zout_Gyro_16_bit = (short) (GyroData[4]<<8 | GyroData[5]);           // Compute 16-bit Z-axis output value                                           // Gyro data converted to dps      Roll = (float) (Xout_Gyro_16_bit) / SENSITIVITY_250;          // Compute X-axis output value in dps      Pitch = (float) (Yout_Gyro_16_bit) / SENSITIVITY_250;         // Compute Y-axis output value in dps      Yaw = (float) (Zout_Gyro_16_bit) / SENSITIVITY_250;           // Compute Z-axis output value in dps                               // Temperature data      Temp = I2C_ReadRegister(FXAS21002C_I2C_ADDRESS, GYRO_TEMP_REG);                   }   7. The calculated values can be watched in the "Variables" window on the top right of the Debug perspective or in the FreeMASTER application. To open and run the FreeMASTER project, install the FreeMASTER application​ and FreeMASTER Communication Driver. I guess this is enough to let you start experimenting with the FRDM-STBC-AGM01 board. Attached you can find the complete source code written in the CW for MCU's v10.6 including the FreeMASTER project. If there are any questions regarding this simple application, do not hesitate to ask below. Your feedback or suggestions are also welcome. Regards, Tomas
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Hi Everyone,   I would like to share here one of my examples I created for the FXLS8471Q accelerometer while working with the Freescale FRDM-KL25Z platform and FRDM-FXS-MULT2-B sensor expansion board. It illustrates the use of the embedded FIFO buffer to collect the 14-bit acceleration data that are read from the FIFO using an interrupt technique through the SPI interface. For details on the configurations of the FIFO buffer as well as more specific examples and application benefits, please refer to the AN4073.   The FXLS8471Q is initialized as follows:   void FXLS8471Q_Init (void) {/* The software reset does not work properly in SPI mode as described in Appendix A of the FXLS8471Q data sheet. Therefore the following piece of the code is not used. I have shortened R46 on the FRDM-FXS-MULTI-B board to activate a hardware reset. FXLS8471Q_WriteRegister(CTRL_REG2, 0x40); // Reset all registers to POR values */   FXLS8471Q_WriteRegister(CTRL_REG1, 0x00); // Standby mode FXLS8471Q_WriteRegister(F_SETUP_REG, 0xA0); // FIFO Fill mode, 32 samples   FXLS8471Q_WriteRegister(CTRL_REG4, 0x40); // Enable FIFO interrupt, push-pull, active low   FXLS8471Q_WriteRegister(CTRL_REG5, 0x40); // Route the FIFO interrupt to INT1 - PTA5   FXLS8471Q_WriteRegister(CTRL_REG1, 0x19); // ODR = 100Hz, Active mode }       In the ISR, only the interrupt flag is cleared and the FIFO_DataReady variable is set to indicate that the FIFO is full.   void PORTA_IRQHandler() { PORTA_PCR5 |= PORT_PCR_ISF_MASK; // Clear the interrupt flag FIFO_DataReady = 1; }       Once the FIFO_DataReady variable is set, the STATUS register (0x00) is read to clear the FIFO interrupt status bit and deassert the INT1 pin. Afterwars the FIFO is read using a 192-byte (3 x 2 x 32 bytes) burst read starting from the OUT_X_MSB register (0x01). Then the raw acceleration data are converted to signed 14-bit values and real values in g’s.   if (FIFO_DataReady) { FIFO_DataReady = 0; FIFO_Status = FXLS8471Q_ReadRegister(STATUS_REG); // Read the Status register to clear the FIFO interrupt status bit FXLS8471Q_ReadMultiRegisters(OUT_X_MSB_REG, 6*Watermark_Val, AccelData); // Read the FIFO using a burst read     for (i = 0; i < Watermark_Val; i++)   { // 14-bit accelerometer data   Xout_Accel_14_bit[i] = ((short) (AccelData[0 + i*6]<<8 | AccelData[1 + i*6])) >> 2; // Compute 14-bit X-axis acceleration output values   Yout_Accel_14_bit[i] = ((short) (AccelData[2 + i*6]<<8 | AccelData[3 + i*6])) >> 2; // Compute 14-bit Y-axis acceleration output values  Zout_Accel_14_bit[i] = ((short) (AccelData[4 + i*6]<<8 | AccelData[5 + i*6])) >> 2; // Compute 14-bit Z-axis acceleration output values   // Accelerometer data converted to g's   Xout_g[i] = ((float) Xout_Accel_14_bit[i]) / SENSITIVITY_2G; // Compute X-axis output values in g's  Yout_g[i] = ((float) Yout_Accel_14_bit[i]) / SENSITIVITY_2G; // Compute Y-axis output values in g's   Zout_g[i] = ((float) Zout_Accel_14_bit[i]) / SENSITIVITY_2G; // Compute Z-axis output values in g's   } }       Deassertion of the INT1 pin after reading the STATUS register (0x00).       ODR is set to 100Hz, so the FIFO is read every 320 ms (10 ms x 32 samples).       The calculated values can be watched in the "Variables" window on the top right of the Debug perspective.       Attached you can find the complete source code written in the CW for MCU's 10.6. If there are any questions regarding this simple example project, please feel free to ask below. Your feedback or suggestions are also welcome.   Regards, Tomas Original Attachment has been moved to: FRDM-KL25Z-FXLS8471Q-FIFO.rar
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Hi Everyone,   In this document I would like to go through a simple bare-metal example code I created for the recently released FRDMSTBC-A8471 development board with the NXP FXLS8471Q 3-axis linear accelerometer. This board is compatible with most NXP Freedom development boards and I decided to use one of the most popular - FRDM-KL25Z. The FreeMASTER tool is used to visualize the acceleration data that are read from the FXLS8471Q using an interrupt technique through the SPI interface. I will not cover the Sensor Toolbox software and Intelligent Sensing Framework (ISF) which also support this board.   This example illustrates:   1. Initialization of the MKL25Z128 MCU (mainly SPI and PORT modules). 2. SPI data write and read operations. 3. Initialization of the FXLS8471Q to achieve the highest resolution. 4. Simple offset calibration based on the AN4069. 5. Output data reading using an interrupt technique. 6. Conversion of the output values from registers 0x01 – 0x06 to real acceleration values in g’s. 7. Visualization of the output values in the FreeMASTER tool.     1. As you can see in the FRDMSTBC-A8471​/FRDM-KL25Z​ schematics and the image below, SPI signals are routed to the SPI0 module of the KL25Z MCU and the INT1 output is connected to the PTD4 pin. The PTD0 pin (Chip Select) is not controlled automatically by SPI0 module, hence it is configured as a general-purpose output. The INT1 output of the FXLS8471Q is configured as a push-pull active-low output, so the corresponding PTD4 pin configuration is GPIO with an interrupt on falling edge.The core/system clock frequency is 20.97 MHz and SPI clock is 524.25 kHz.     The MCU is, therefore, configured as follows.   /****************************************************************************** * MCU initialization function ******************************************************************************/   void MCU_Init(void) {   //SPI0 module initialization   SIM_SCGC4 |= SIM_SCGC4_SPI0_MASK; // Turn on clock to SPI0 module   SIM_SCGC5 |= SIM_SCGC5_PORTD_MASK; // Turn on clock to Port D module   PORTD_PCR1 = PORT_PCR_MUX(0x02); // PTD1 pin is SPI0 CLK line   PORTD_PCR2 = PORT_PCR_MUX(0x02); // PTD2 pin is SPI0 MOSI line   PORTD_PCR3 = PORT_PCR_MUX(0x02); // PTD3 pin is SPI0 MISO line   PORTD_PCR0 = PORT_PCR_MUX(0x01); // PTD0 pin is configured as GPIO (CS line driven manually)   GPIOD_PSOR |= GPIO_PSOR_PTSO(0x01); // PTD0 = 1 (CS inactive)   GPIOD_PDDR |= GPIO_PDDR_PDD(0x01); // PTD0 pin is GPIO output     SPI0_C1 = SPI_C1_SPE_MASK | SPI_C1_MSTR_MASK; // Enable SPI0 module, master mode   SPI0_BR = SPI_BR_SPPR(0x04) | SPI_BR_SPR(0x02); // BaudRate = BusClock / ((SPPR+1) * 2^(SPR+1)) = 20970000 / ((4+1) * 2^(2+1)) = 524.25 kHz     //Configure the PTD4 pin (connected to the INT1 of the FXLS8471Q) for falling edge interrupts   PORTD_PCR4 |= (0|PORT_PCR_ISF_MASK| // Clear the interrupt flag                   PORT_PCR_MUX(0x1)| // PTD4 is configured as GPIO                   PORT_PCR_IRQC(0xA)); // PTD4 is configured for falling edge interrupts     //Enable PORTD interrupt on NVIC   NVIC_ICPR |= 1 << ((INT_PORTD - 16)%32);   NVIC_ISER |= 1 << ((INT_PORTD - 16)%32); }     2. The FXLS8471Q uses the ‘Mode 0′ SPI protocol, which means that an inactive state of clock signal is low and data are captured on the leading edge of clock signal and changed on the falling edge.   The falling edge on the CS pin starts the SPI communication. A write operation is initiated by transmitting a 1 for the R/W bit. Then the 8-bit register address, ADDR[7:0] is encoded in the first and second serialized bytes. Data to be written starts in the third serialized byte. The order of the bits is as follows:   Byte 0: R/W, ADDR[6], ADDR[5], ADDR[4], ADDR[3], ADDR[2], ADDR[1], ADDR[0] Byte 1: ADDR[7], X, X, X, X, X, X, X Byte 2: DATA[7], DATA[6], DATA[5], DATA[4], DATA[3], DATA[2], DATA[1], DATA[0]   The rising edge on the CS pin stops the SPI communication.   Below is the write operation which writes the value 0x3D to the CTRL_REG1 (0x3A).   Similarly a read operation is initiated by transmitting a 0 for the R/W bit. Then the 8-bit register address, ADDR[7:0] is encoded in the first and second serialized bytes. The data is read from the MISO pin (MSB first).   The screenshot below shows the read operation which reads the correct value 0x6A from the WHO_AM_I register (0x0D).   Multiple read operations are performed similar to single read except bytes are read in multiples of eight SCLK cycles. The register address is auto incremented so that every eighth next clock edges will latch the MSB of the next register.   A burst read of 6 bytes from registers 0x01 to 0x06 is shown below. It also shows how the INT1 pin is automatically cleared by reading the acceleration output data.     3. The dynamic range is set to ±2g and to achieve the highest resolution, the LNOISE bit is set and the lowest ODR (1.56Hz) and the High Resolution mode are selected (more details in AN4075). The DRDY interrupt is enabled and routed to the INT1 interrupt pin that is configured to be a push-pull, active-low output.   /****************************************************************************** * FXLS8471Q initialization function ******************************************************************************/   void FXLS8471Q_Init (void) {   FXLS8471Q_WriteRegister(CTRL_REG2, 0x02); // High Resolution mode   FXLS8471Q_WriteRegister(CTRL_REG3, 0x00); // Push-pull, active low interrupt   FXLS8471Q_WriteRegister(CTRL_REG4, 0x01); // Enable DRDY interrupt   FXLS8471Q_WriteRegister(CTRL_REG5, 0x01); // DRDY interrupt routed to INT1-PTD4   FXLS8471Q_WriteRegister(CTRL_REG1, 0x3D); // ODR = 1.56Hz, Reduced noise, Active mode   }     4. A simple offset calibration method is implemented according to the AN4069​.   /****************************************************************************** * Simple accelerometer offset calibration ******************************************************************************/   void FXLS8471Q_Calibrate (void) {   unsigned char reg_val = 0;     while (!reg_val) // Wait for a first set of data    {     reg_val = FXLS8471Q_ReadRegister(STATUS_REG) & 0x08;   }      FXLS8471Q_ReadMultiRegisters(OUT_X_MSB_REG, 6, AccData); // Read data output registers 0x01-0x06       Xout_14_bit = ((short) (AccData[0]<<8 | AccData[1])) >> 2; // Compute 14-bit X-axis output value   Yout_14_bit = ((short) (AccData[2]<<8 | AccData[3])) >> 2; // Compute 14-bit Y-axis output value   Zout_14_bit = ((short) (AccData[4]<<8 | AccData[5])) >> 2; // Compute 14-bit Z-axis output value      Xoffset = Xout_14_bit / 8 * (-1); // Compute X-axis offset correction value   Yoffset = Yout_14_bit / 8 * (-1); // Compute Y-axis offset correction value   Zoffset = (Zout_14_bit - SENSITIVITY_2G) / 8 * (-1); // Compute Z-axis offset correction value      FXLS8471Q_WriteRegister(CTRL_REG1, 0x00); // Standby mode to allow writing to the offset registers   FXLS8471Q_WriteRegister(OFF_X_REG, Xoffset);   FXLS8471Q_WriteRegister(OFF_Y_REG, Yoffset);   FXLS8471Q_WriteRegister(OFF_Z_REG, Zoffset);      FXLS8471Q_WriteRegister(CTRL_REG1, 0x3D); // ODR = 1.56Hz, Reduced noise, Active mode }     5. In the ISR, only the interrupt flag is cleared and the DataReady variable is set to indicate the arrival of new data.   /****************************************************************************** * PORT D Interrupt handler ******************************************************************************/   void PORTD_IRQHandler() {   PORTD_PCR4 |= PORT_PCR_ISF_MASK; // Clear the interrupt flag   DataReady = 1; }     6. The output values from accelerometer registers 0x01 – 0x06 are first converted to signed 14-bit values and afterwards to real values in g’s.   if (DataReady)     // Is a new set of data ready? {   DataReady = 0;     FXLS8471Q_ReadMultiRegisters(OUT_X_MSB_REG, 6, AccData); // Read data output registers 0x01-0x06                                                    Xout_14_bit = ((short) (AccData[0]<<8 | AccData[1])) >> 2; // Compute 14-bit X-axis output value   Yout_14_bit = ((short) (AccData[2]<<8 | AccData[3])) >> 2; // Compute 14-bit Y-axis output value   Zout_14_bit = ((short) (AccData[4]<<8 | AccData[5])) >> 2; // Compute 14-bit Z-axis output value                                        Xout_g = ((float) Xout_14_bit) / SENSITIVITY_2G; // Compute X-axis output value in g's   Yout_g = ((float) Yout_14_bit) / SENSITIVITY_2G; // Compute Y-axis output value in g's   Zout_g = ((float) Zout_14_bit) / SENSITIVITY_2G; // Compute Z-axis output value in g's }     7. The calculated values can be watched in the "Variables" window on the top right of the Debug perspective or in the FreeMASTER application. To open and run the FreeMASTER project, install the FreeMASTER 2.0 application and FreeMASTER Communication Driver.         Attached you can find the complete source code written in the CW for MCU's v10.6​ including the FreeMASTER project.   If there are any questions regarding this simple application, please feel free to ask below. Your feedback or suggestions are also welcome.   Regards, Tomas
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FXLS93xxx 是NXP针对底盘安全领域的PSI5接口的加速度传感器。FXPS71407BPS 是NXP针对气囊中侧碰,行人保护等应用推出的PSI5接口的压力传感器。 FXLS93xxxx/FXPS71407BPS 芯片出厂时,COMMTYPE中COMMTYPE[2:0]被设置成0x1. 除COMMTYPE中这一位,其它寄存器默认值都是0. 虽然都是QFN 4mm x 4mm 封装,但pin脚顺序不同,PCB不共用 下面仅介绍了在PSI5模式下最常配置的几个寄存器,其它的配置请参考对应的datasheet 芯片烧写OTP前,有默认模式(un-programmed PSI5)输出 PSI5-P16C-500/2L with 400 Hz, 4-Pole low-pass filter.   SOURCEID_0, SOURCEID_1, SOURCEID_2, SOURCEID_3的配置 SOURCEID_0, SOURCEID_1 对应CH0 SOURCEID_2, SOURCEID_3对应CH1 具体的CH0 和CH1对应的加速度传感器在datasheet 第一页中可以找到       注:PIS5异步模式(Async mode), 仅SOURCEID_0 有效   例: FXLS93220, 这是X单轴的,它仅能使用Channel 0, 所以配置中仅能配置SOURCEID_0 或 SOURCEID_1 。   FXLS93421, CH0对应的是X轴Middle-g, CH1对应的是Z-axis Low-g的加速度传感器。 如果要使用Z-axis Low-g的加速度传感器,则配置SOURCEID_2 或 SOURCEID_3,如果一个同步周期内只需发一组加速度值,则配SOURCEID_2 就可以了。     SOURCEID_0 中PDCMFORMAT[2:0],例:PSI5需要配置为P16CRC-1000/3H ,数据需要以16-bit 输出, 则配置PDCMFORMAT[2:0] =0b1xx   PSI5_CFG ($25) 最常需配置的位 P_CRC(默认是奇偶校验,写1是CRC校验),ASYNC(默认是Sync mode, 同步模式, 写1改为异步模式Async) EMSG_EXT 如果模块的spec里没有特别要求,建议写1,因为在模块失效时,可以提供更多的失效信息,便于做FA. PSI5_CFG 其它位的配置主要看系统的结构或接收端是否支持。 PDCM_RSPSTx($26-$2B) 在Sync mode下,PDCM_RSPST0,PDCM_RSPST1,PDCM_RSPST2,PDCM_RSPST3 对应于SOURCEID_0, SOURCEID_1,SOURCEID_2, SOURCEID_3 的数据开始发送的时间, Start time, 这里配置的是tTIMESLOTx的值, tA_SYNC_DLY只有50-600ns.   例: SOURCEID_2的数据开始发送的Timeslot start time是244 μs, 则配置PDCM_RSPST2_L = 0xF4 通过配置的SOURCEID_x选择对应的CHx_CFG_U1,CHx_CFG_U2,CHx_CFG_U3,CHx_CFG_U4,CHx_CFG_U5进行配置。 PDCM_CMD_B_L($38) PDCM_CMD_B_H($39) PSI5 Command Blocking Time 全0为默认值450us. CH0_CFG_U1($40), CH1_CFG_U1($48) 根据产品需求,在下表中选择合适的LPF[3:0]和SAMPLERATE[1:0]. 该滤波器更详细的内容见Low-pass filter 章节     CH0_CFG_U2($41), CH1_CFG_U2($49)  寄存器U_SNS_MULT[7:0]的配置需结合CHx_CFG_U1中USER_SNS_SHIFT[1:0]一起配置。通过这个配置,可以得到对应的sensitivity和g-range. 具体计算可以参考uGen6UserSensitivityMultiplierCaculation.xslx 文件。注:PSI5 10-bit数据输出范围是-480 ~ 480 LSB, PSI5 16-bit数据输出范围为-30720 ~ 30720 LSB. (这是PSI5协议规定的) CH0_CFG_U3($42), CH1_CFG_U3 ($4A) CHxDATATYPE0 和 CHxDATATYPE1 , 默认是使能Offset cancellation自动归零功能的。通过这个寄存器配置,可以关闭该功能。 MOVEAVG[1:0] 默认是使用的LPF, 通过MOVEAVG[1:0]配置,可以关闭LPF, 使能平均值滤波。 CH0_CFG_U4($43), CH1_CFG_U4($4B) INVERT 如发现数据输出的正负和期望值是相反的,则将该位置1 假设将传感器转90度,即Offset为1g,当OC_FILT[1:0] 为0时 则由于OC Rate Limiting 的速度是1LSB/4s for PSI5 10-bit(or 16LSB/s for PSI5 16-bit). 如果1g对应的输出是32个LSB (PSI5 10-bit),则需要32*0.25 = 128s实现1g的自动归零功能。 如果使用0.04Hz,OC_FILT[1:0]=1,关闭OC Rate Limiting功能,则 18.36sec 实现归零 final value (+/-1%) . (最快的) 如果使用0.005Hz,OC_FILT[1:0]=2,?   CH0_U_OFFSET_L($55), CH0_U_OFFSET_H($56), CH1_U_OFFSET_L($5D), CH1_U_OFFSET_H($5E) 当测量轴向在重力加速度方向,则需要配置该寄存器。配置的具体值参考uGen6UserSensitivityMultiplierCaculation.xslx 文件。例如FXLS93421, 当使用Z-axis在垂直方向时,由于重力加速度的耦合,使Offset超过了400mg,PSI5总线会报Offest Error信息(EMSG_EXT=1)或是Sensor Defect Error信息(EMSG_EXT=0). 以上仅是FXLS93xxxx/FXPS71407BPS最常做的配置,注意FXPS71407BPS和FXLS93xxxx的配置还是有很多区别的,如只支持10-bit PSI5 输出,所以请以对应的datasheet为准。
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This is the errata corresponding to ISF 2.1 for Kenetis with updates associated with Rev 2 of the PEUPD file released on 23 April 2015.
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Hi Everyone, This tutorial is a detailed guide on how to import an ISSDK based example project (e.g. mma845x_interrupt) into MCUXpresso IDE, build and run it on the Freedom board (e.g. FRDM-KL27Z). If you intend to use another ISSDK example project/board, you can always follow this guide. A complete list of MCU boards, sensor kits and sensors supported by ISSDK is available in the ISSDK Release notes. 1. Download the FRDM-KL27Z SDK Open a web browser, navigate to the MCUXpresso homepage and select “Login to view configurations” to start a new configuration. You will be redirected to login to nxp.com. Enter your account information or register for a new account. Back on the MCUXpresso homepage, select the drop-down box to create a New Configuration. Select the board (FRDM-KL27Z) from the list and provide a name for the configuration. Select “Specify Additional Configuration Settings” to choose the Host OS, Toolchain (MCUXpresso IDE) and Middleware (ISSDK). Select Configuration Settings: Host OS (example: Windows) Toolchain/IDE (MCUXpresso IDE) Middleware (ISSDK) Once the configurations are set, select “Go to SDK Builder”.   Select “Request Build” to download the SDK. Once the build request is completed, download the SDK. Agree to Software Terms and Conditions. Unzip SDK to a folder (e.g. SDK_2.2.1_FRDM-KL27Z). 2. Import the SDK_2.1.1_FRDM-KL27Z into MCUXpresso IDE Open MCUXpresso IDE. Set the workspace directory of your choice and click on OK. Switch to the Installed SDKs view within the MCUXpresso IDE window. Open Windows Explorer, and drag and drop the SDK_2.2.1_FRDM-KL27Z (unzipped) file into the installed SDKs view. You will get the following pop-up so click on OK to continue the import.   The installed SDK will appear in the Installed SDKs view. 3. Import and build the ISSDK based mma845x_interrupt example project Find the Quickstart Panel in the lower left hand corner and select Import SDK example(s) Click on the FRDM-KL27Z board and then click on Next. Use the arrow button to expand the issdk_examples category, and then click the checkbox next to mma845x_interrupt to select that project. Then, click on Next. On the next screen, click the checkbox to Redirect printf/scanf to UART so that the terminal output gets sent out the UART instead of using semi-hosting through the debugger. Then click on Finish. Now build the project by clicking on the project name in the Project Explorer view and then click on the Build icon in the Quickstart Panel. You can see the status of the build in the Console view. 4. Run the mma845x_interrupt example project   Now that the project has been compiled, we can flash it to the board and run it. Make sure the FRDM-KL27Z board is plugged in, and click on Debug ‘frdmkl27z_issdk_examples_sensors_mma8451q_mma845x_interrupt’ [Debug] MCUXpresso will probe for connected boards and should find the OpenSDA debug probe that is part of the integrated OpenSDA circuit on the FRDM-KL27Z board. Click on OK to continue. The firmware will be downloaded to the board and the debugger started. Open a Terminal program (e.g. Tera Term) and connect to the FRDM-KL27Z COM port that it enumerated as. Use 115200 baud, 8 data, 1 stop, no parity. Start the application in the MCUXpresso IDE by clicking the "Resume" button. The application is now running and signed 14-bit accelerometer output values are displayed on the terminal. To modify the initial register settings of the MMA8451 accelerometer, find the mma845x_Config_Isr[] structure and change it according to your needs. Well done if you managed to follow along and get it all working. If there are any questions, do not hesitate to ask below. Your feedback or suggestions are also welcome. Regards, Tomas
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