Hi Everyone,   As I am often asked for a simple bare metal example code illustrating the use of the accelerometer transient detection function, I have decided to share here one of my examples I created for the FXLS8471Q accelerometer while working with the NXP FRDM-KL25Z platform and FRDM-FXS-MULT2-B sensor expansion board.   This example code complements the Python code snippet from the AN4693. The FXLS8471Q is set for detection of an “instantaneous” acceleration change exceeding 315mg for a minimum period of 40 ms on either the X or Y axes. Once an event is triggered, an interrupt will be generated on the INT1 pin:   void FXLS8471Q_Init (void) { FXLS8471Q_WriteRegister(TRANSIENT_THS_REG, 0x85); // Set threshold to 312.5mg (5 x 62.5mg ) FXLS8471Q_WriteRegister(TRANSIENT_COUNT_REG, 0x02); // Set debounce timer period to 40ms FXLS8471Q_WriteRegister(TRANSIENT_CFG_REG, 0x16); // Enable transient detection for X and Y axis, latch enabled FXLS8471Q_WriteRegister(CTRL_REG4, 0x20); // Acceleration transient interrupt enabled FXLS8471Q_WriteRegister(CTRL_REG5, 0x20); // Route acceleration transient interrupt to INT1 - PTA5 FXLS8471Q_WriteRegister(CTRL_REG1, 0x29); // ODR = 12.5Hz, Active mode } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     In the ISR, only the interrupt flag is cleared and the TRANSIENT_SRC (0x1E) register is read in order to clear the SRC_TRANS status bit and deassert the INT1 pin, as shown on the screenshot below.   void PORTA_IRQHandler() { PORTA_PCR5 |= PORT_PCR_ISF_MASK; // Clear the interrupt flag IntSource = FXLS8471Q_ReadRegister(TRANSIENT_SRC_REG); // Read the TRANSIENT_SRC register to clear the SRC_TRANS flag in the INT_SOURCE register EventCounter++; } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍       Attached you can find the complete source code. If there are any questions regarding this simple example code, please feel free to ask below. Your feedback or suggestions are also welcome.   Regards, Tomas

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

Hi Everyone,   I would like to present another example code/demo that reads acceleration data from the Xtrinsic MMA8491Q digital accelerometer and visualizes them using the FreeMASTER tool via USBDM interface. I have used recently released Xtrinsic MEMS sensors board that features three types of Xtrinsic sensors including the MMA8491Q and is fully compatible with the Freescale FRDM-KL25Z platform.   In comparison with other Xtrinsic accelerometers, the MMA8491Q is turned on at the rising edge on the EN pin and acquires only one sample for each of the three axes. It does not have any interrupt pins, instead there are three push-pull logic outputs which provide tilt detection at 45 degrees as the original target application was tamper detection. However, it is possible to read the 14-bit output values through the I2C port as demonstrated in my example below.   According to the User Manual, both SCL and SDA lines are connected through the 4.7K pull-up resistors to the I2C1 module (PTE1 and PTE0 pins) on the KL25Z128 MCU and the EN pin is connected to the PTA13 pin. The EN input needs to be kept high until a new data is ready (max. 900us) and read. In my code I use the PIT module to wait 1ms before reading the output values. This timer is also used to read the output data periodically at a fixed rate. The timeout period of the PIT is set to 500us. 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_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  = 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 PTA13 pin as an output to drive the EN input of the MMA8491Q        SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;       // Turn on clock to Port A module        PORTA_PCR13 = PORT_PCR_MUX(1);           // PTA13 is configured as GPIO        GPIOA_PCOR |= 1<<13;                     // Set PTA13 pin low        GPIOA_PDDR |= 1<<13;                     // PTA13 pin is an output                //PIT initialization        SIM_SCGC6 |= SIM_SCGC6_PIT_MASK;         // Turn on clock to to the PIT module        PIT_LDVAL0 = 5240;                       // Timeout period = 500us        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 interrupt service routine (ISR), there is a variable Counter that is increased by one on every PIT interrupt (500us) and its value is then compared with two preset values. The first preset value EN_HIGH_TIME determines how long the EN pin will remain high to ensure a valid reading of a new set of output data. The second preset value DATA_UPDATE_PERIOD corresponds to the desired output data rate. At the end of the ISR, the PIT interrupt flag is cleared.   void PIT_IRQHandler() {        static int Counter = 0;        Counter++;                                   // Each increment represents 500us        switch (Counter)     {             case 1:             GPIOA_PSOR |= 1<<13;                 // Set EN pin high                      break;             caseEN_HIGH_TIME:                        // 1ms passed             DataReady = 1;                       // Data is ready                      break;             caseDATA_UPDATE_PERIOD:                  // 100ms passed             Counter = 0;                         // Clear Counter at the end of the sample period                      break;             default:                      break;     }        PIT_TFLG0 |= PIT_TFLG_TIF_MASK;              // Clear PIT interrupt flag }   In the main loop, the DataReady variable is periodically checked and if it is set, the accelerometer data registers 0x01 - 0x06 are read and then the acceleration in units of g is calculated. Finally the EN pin is set low to reduce the current consumption and the DataReady variable is cleared.   if (DataReady)                                                                  // Is a new set of data ready? {                  AccData[0] = I2C_ReadRegister(MMA8491Q_I2C_ADDRESS, OUT_X_MSB_REG);         // [7:0] are 8 MSBs of the 14-bit X-axis sample      AccData[1] = I2C_ReadRegister(MMA8491Q_I2C_ADDRESS, OUT_X_LSB_REG);         // [7:2] are the 6 LSB of 14-bit X-axis sample      AccData[2] = I2C_ReadRegister(MMA8491Q_I2C_ADDRESS, OUT_Y_MSB_REG);         // [7:0] are 8 MSBs of the 14-bit Y-axis sample      AccData[3] = I2C_ReadRegister(MMA8491Q_I2C_ADDRESS, OUT_Y_LSB_REG);         // [7:2] are the 6 LSB of 14-bit Y-axis sample      AccData[4] = I2C_ReadRegister(MMA8491Q_I2C_ADDRESS, OUT_Z_MSB_REG);         // [7:0] are 8 MSBs of the 14-bit Z-axis sample      AccData[5] = I2C_ReadRegister(MMA8491Q_I2C_ADDRESS, OUT_Z_LSB_REG);         // [7:2] are the 6 LSB of 14-bit Z-axis sample        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;          // Compute X-axis output value in g's      Yout_g = ((float) Yout_14_bit) / SENSITIVITY;          // Compute Y-axis output value in g's      Zout_g = ((float) Zout_14_bit) / SENSITIVITY;          // Compute Z-axis output value in g's                                              GPIOA_PCOR |= 1<<13;       // Set EN pin low      DataReady = 0;                                                                                                                                 }                       The calculated values can be watched in the "Variables" window on the top right of the Debug perspective or in the FreeMASTER application.       Attached you can find the complete source code written in the CW 10.3 as well as 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  

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

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

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

Hi Everyone,   As I am often asked for a simple bare metal example code illustrating the use of the embedded rate threshold detection function, I have decided to share here one of my examples I created for the FXAS21002C gyroscope while working with the NXP FRDM-KL25Z platform and FRDM-FXS-MULT2-B sensor expansion board.   The FXAS21002C is set for detection of an angular rate exceeding 96 dps for a minimum period of 20 ms on either the X or Y axes. Once an event is triggered, an interrupt will be generated on the INT1 pin:   void FXAS21002_Init (void) {     unsigned char reg_val = 0;                 I2C_WriteRegister(FXAS21002_I2C_ADDRESS, CTRL_REG1, 0x40);      // Reset all registers to POR values                 Pause(0x631);                                                   // ~1ms delay                             do                                                              // Wait for the RST bit to clear     {         reg_val = I2C_ReadRegister(FXAS21002_I2C_ADDRESS, CTRL_REG1) & 0x40;     }    while (reg_val);                 I2C_WriteRegister(FXAS21002_I2C_ADDRESS, RT_THS_REG, 0x05);     // Set threshold to 96 dps             I2C_WriteRegister(FXAS21002_I2C_ADDRESS, RT_COUNT_REG, 0x02);   // Set debounce timer period to 20 ms    I2C_WriteRegister(FXAS21002_I2C_ADDRESS, RT_CFG_REG, 0x0B);     // Enable rate threshold detection for X and Y axis, latch enabled  I2C_WriteRegister(FXAS21002_I2C_ADDRESS, CTRL_REG2, 0x30);      // Rate threshold interrupt enabled and routed to INT1    I2C_WriteRegister(FXAS21002_I2C_ADDRESS, CTRL_REG1, 0x0E);      // ODR = 100 Hz, Active mode    }     In the ISR, only the interrupt flag is cleared and the RT_SRC register (0x0F) is read in order to clear the EA status bit and deassert the INT1 pin, as shown on the screenshot below. 0x4C in the RT_SRC register indicates that the rate threshold event has been detected on the Y-axis and was negative.   void PORTA_IRQHandler() {    PORTA_PCR5 |= PORT_PCR_ISF_MASK;                                   // Clear the interrupt flag     IntSource = I2C_ReadRegister(FXAS21002_I2C_ADDRESS, RT_SRC_REG);   // Read the RT_SRC register to clear the EA flag and deassert the INT1 pin EventCounter++;       }       Attached you can find the complete source code. If there are any questions regarding this simple example code, please feel free to ask below. Your feedback or suggestions are also welcome.   Regards, Tomas Original Attachment has been moved to: FRDM-KL25Z-FXAS21002-Angular-rate-detection-using-interrupts.rar

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

Current errata for ISF 2.1

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.

Hi Everyone,   If you are interested in a simple bare metal example code illustrating the use of the FXLS8471Q orientation detection function, please find below one of my examples I created for the FXLS8471Q accelerometer while working with the NXP FRDM-KL25Z platform and FRDMSTBC-A8471 board.   This example code complements the code snippet from the  AN4068.   void FXLS8471Q_Init (void) { FXLS8471Q_WriteRegister(CTRL_REG1, 0x00); // Standby mode FXLS8471Q_WriteRegister(PL_CFG_REG, 0x40); // Enable orientation detection FXLS8471Q_WriteRegister(PL_BF_ZCOMP_REG, 0x43); // Back/Front trip point set to 75°, Z-lockout angle set to 25° FXLS8471Q_WriteRegister(P_L_THS_REG, 0x14); // Threshold angle = 45°, hysteresis = 14° FXLS8471Q_WriteRegister(PL_COUNT_REG, 0x05); // Debounce counter set to 100ms at 50Hz FXLS8471Q_WriteRegister(CTRL_REG3, 0x00); // Push-pull, active low interrupt FXLS8471Q_WriteRegister(CTRL_REG4, 0x10); // Orientation interrupt enabled FXLS8471Q_WriteRegister(CTRL_REG5, 0x10); // Route orientation interrupt to INT1 - PTD4 FXLS8471Q_WriteRegister(CTRL_REG1, 0x21); // ODR = 50Hz, Active mode }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     In the ISR, only the interrupt flag is cleared and the PL_STATUS (0x10) register is read in order to:   - Clear the SRC_LNDPRT flag in the INT_SOURCE register and deassert the INT1 pin, as shown on the screenshot below. - Get orientation information. 0x82 in this example corresponds to "Portrait down" orientation.   void PORTD_IRQHandler() { PORTD_PCR4 |= PORT_PCR_ISF_MASK; // Clear the interrupt flag PL_Status = FXLS8471Q_ReadRegister(PL_STATUS_REG); // Read the PL_STATUS register to clear the SRC_LNDPRT flag in the INT_SOURCE register }‍‍‍‍‍‍‍‍‍‍       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

Hi Everyone,   If you are interested in a simple bare metal example code illustrating the use of the accelerometer motion detection function, please find below one of my examples I created for the FXLS8471Q accelerometer while working with the NXP FRDM-KL25Z platform and FRDMSTBC-A8471 board.   The FXLS8471Q is set to detect motion exceeding 315mg for a minimum period of 40 ms on either the X or Y axis. Once an event is triggered, an interrupt will be generated on the INT1 pin:   void FXLS8471Q_Init (void) { FXLS8471Q_WriteRegister(FT_MT_THS_REG, 0x85); // Set threshold to 312.5mg (5 x 62.5mg ) FXLS8471Q_WriteRegister(FF_MT_COUNT_REG, 0x02); // Set debounce timer period to 40ms FXLS8471Q_WriteRegister(FF_MT_CFG_REG, 0xD8); // Latch enabled, motion detection enabled for X and Y axis FXLS8471Q_WriteRegister(CTRL_REG4, 0x04); // Motion interrupt enabled FXLS8471Q_WriteRegister(CTRL_REG5, 0x04); // Route motion interrupt to INT1 - PTD4 FXLS8471Q_WriteRegister(CTRL_REG1, 0x29); // ODR = 12.5Hz, Active mode }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     In the ISR, only the interrupt flag is cleared and the FF_MT_SRC (0x16) register is read in order to clear the SRC_FFMT flag in the INT_SOURCE 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 IntSource = FXLS8471Q_ReadRegister(FF_MT_SRC_REG); // Read the FF_MT_SRC register to clear the SRC_FFMT flag in the INT_SOURCE register EventCounter++; }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍       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

  LGA 8 PACKAGE 5.0 mm x 3.0 mm x 1.1 mm  

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

Hi Everyone, I would like to share here one of my examples I created for the MPL3115A2 while working with the NXP FRDM-KL25Z platform and FRDMSTBC-P3115 shield board. It illustrates the use of the embedded FIFO buffer to collect either pressure/temperature or altitude/temperature data that are read from the FIFO using an interrupt technique through the I2C interface. The FIFO is set to store the maximum number of samples (32). Each sample consists of 3 bytes of pressure (or altitude) data and 2 bytes of temperature data. Therefore 160 bytes (32 x (3 + 2)) in total are read from the FIFO when the FIFO is full and the FIFO interrupt is asserted. The MPL3115A2 is initialized as follows. /****************************************************************************** * MPL3115A2 initialization function ****************************************************************************** void MPL3115A2_Init (void) { I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, CTRL_REG1, 0x04); // Reset all registers to POR values Pause(0x631); // ~1ms delay I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, F_SETUP_REG, 0xA0); // FIFO Fill mode, 32 samples I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, CTRL_REG4, 0x40); // Enable FIFO interrupt I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, CTRL_REG5, 0x40); // Route the FIFO interrupt to INT1 - PTA5 I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, CTRL_REG2, 0x00); // Time step = ~1s I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, CTRL_REG3, 0x00); // Push-pull, active low interrupt I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, CTRL_REG1, 0x39); // Active barometer mode, OSR = 128 //I2C_WriteRegister(MPL3115A2_I2C_ADDRESS, CTRL_REG1, 0xB9); // Active altimeter mode, OSR = 128 }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ In the ISR, only the interrupt flag is cleared and the FIFO_DataReady variable is set to indicate that the FIFO is full. /****************************************************************************** * PORT A Interrupt handler ******************************************************************************/ void PORTA_IRQHandler() { PORTA_PCR5 |= PORT_PCR_ISF_MASK; 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 160-byte (5 x 32 bytes) burst read starting from the OUT_P_MSB register (0x01). Then the raw pressure (or altitude) and temperature data are converted to real values. if (FIFO_DataReady) { FIFO_DataReady = 0; FIFO_Status = I2C_ReadRegister(MPL3115A2_I2C_ADDRESS, STATUS_REG); // Read the Status register to clear the FIFO interrupt status bit I2C_ReadMultiRegisters(MPL3115A2_I2C_ADDRESS, OUT_P_MSB_REG, 5*Watermark_Val, RawData); // Read the FIFO using a burst read for (i = 0; i < Watermark_Val; i++) { /* Get pressure, the 20-bit measurement in Pascals is comprised of an unsigned integer component and a fractional component. The unsigned 18-bit integer component is located in OUT_P_MSB, OUT_P_CSB and bits 7-6 of OUT_P_LSB. The fractional component is located in bits 5-4 of OUT_P_LSB. Bits 3-0 of OUT_P_LSB are not used. */ Pressure[i] = (float) (((RawData[0 + i*5] << 16) | (RawData[1 + i*5] << 8) | (RawData[2 + i*5] & 0xC0)) >> 6) + (float) ((RawData[2 + i*5] & 0x30) >> 4) * 0.25; /* Get temperature, the 12-bit temperature measurement in °C is comprised of a signed integer component and a fractional component. The signed 8-bit integer component is located in OUT_T_MSB. The fractional component is located in bits 7-4 of OUT_T_LSB. Bits 3-0 of OUT_T_LSB are not used. */ Temperature[i] = (float) ((short)((RawData[3 + i*5] << 8) | (RawData[4 + i*5] & 0xF0)) >> 4) * 0.0625; /* Get altitude, the 20-bit measurement in meters is comprised of a signed integer component and a fractional component. The signed 16-bit integer component is located in OUT_P_MSB and OUT_P_CSB. The fraction component is located in bits 7-4 of OUT_P_LSB. Bits 3-0 of OUT_P_LSB are not used */ //Altitude[i] = (float) ((short) ((RawData[0 + i*5] << 8) | RawData[1 + i*5])) + (float) (RawData[2 + i*5] >> 4) * 0.0625; } } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Deassertion of the INT1 pin after reading the STATUS register (0x00). The auto acquisition time step is set in this example to the lowest possible value (1s), so the FIFO is read every ~32s. 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. 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

Hi Folks, If you are planning to design an application where a pressure sensor is needed but you are not sure about which kind of Pressure Measurement and Level of Integration is needed, or you even doesn’t know what does that means (like me before start working with pressure sensors), then this document can be useful. First, for a better understanding about what I’m talking about in this document and how pressure sensors and measurement works I’m adding below an image that shows a cross-section of a standard pressure sensor which basically shows the Physical Internal structure of a pressure sensor: What I’m trying to show in this image is the position of the Ports P1 and P2, you will see the importance of these ports and its position for the pressure measurement. Also in this image you can see that the die and the wire bonds are protected with a Silicone Gel, this gel can get damaged leaving the die and the wire bonds exposed to the media if it’s used with different media than dry clean air. Pressure Measurements can be divided into three different categories: Absolute pressure, Gage (Gauge) pressure and Differential pressure. Let’s learn something about these categories: + Absolute pressure refers to the absolute value of the force per-unit-area exerted on a surface. Therefore the absolute pressure is the difference between the pressure at a given point and the absolute zero of pressure or a perfect vacuum. In other words: Pressure is applied on Port P1 of the sensor while the Port P2 of the sensor is a vacuum sealed reference. + Gage (Gauge) pressure is the measurement of the difference between the absolute pressure and the Local atmospheric pressure. In other words: Port P2 of the sensor is exposed to the local atmosphere while Port P1 is where pressure is applied. *Local atmospheric pressure can vary depending on ambient temperature, altitude and local weather conditions. A gage pressure by convention is always positive. A 'negative' gage pressure is defined as vacuum. Vacuum is the measurement of the amount by which the local atmospheric pressure exceeds the absolute pressure. A perfect vacuum is zero absolute pressure. + Differential pressure is simply the measurement of one unknown pressure with reference to another unknown pressure. The pressure measured is the difference between the two unknown pressures. In other words: The difference in pressure between two points is measured where pressure is applied to both sides (Port P1 and Port P2) of sensor. Since a differential pressure is a measure of one pressure referenced to another, it is not necessary to specify a pressure reference. Figure below shows the relationship between Absolute, Gage pressure and Vacuum. Freescale Pressure Sensors can also be divided into three different categories according to the Level of Integration: Uncompensated, Temperature Compensated and Integrated, now let’s learn the difference between these categories: + Uncompensated Pressure Sensors are the most basic pressure sensors according to the level of integration; this type of sensor gives a differential output in the range of millivolts, this output will need to be temperature compensated and amplified with external circuitry before sending it to the MCU’s ADC.   + Compensated Pressure Sensors is the following step according to the level of integration; although this type of sensor also gives you a differential output in the range of millivolts, the given output it’s already internally temperature compensated, so externally you only need to add the amplification circuit before sending the sensor’s signal to the MCU’s ADC. + Integrated Pressure Sensor (IPS) gives you the complete solution embedded into the same package, the output signal of the integrated pressure sensors it’s already internally temperature compensated and amplified (the output range can be from 0 to ~3V or from 0 to ~5V depending on the part number), so you do not have to worry about adding external circuitry (just probably some decoupling capacitors), the sensor signal can be sent directly to the MCU’s ADC. Additional to the mentioned types of Pressure Sensors, we also have some Digital Output Pressure Sensors which can be communicated with the MCU via SPI (MPL115A1 Digital Pressure Sensor) or I2C (MPL115A2 and MPL3115A2 Digital Pressure Sensor). Now that you know about Pressure Measurement and Level of Integration, you can jump into my Community Guideline to select the best Freescale Pressure Sensor Part Number for your application. If there are any questions regarding this document, please feel free to ask below. Your feedback or suggestions are also welcome. Regards, Jose

         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.         

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

     The MC12311 is a highly-integrated, cost-effective, system-in-package (SIP), sub-1GHz wireless node solution with an FSK, GFSK, MSK, or OOK modulation-capable transceiver and low-power HCS08 8-bit microcontroller. The highly integrated RF transceiver operates over a wide frequency range including 315 MHz, 433 MHz, 470 MHz, 868 MHz, 915 MHz, 928 MHz, and 955 MHz in the license-free Industrial, Scientific and Medical (ISM) frequency bands.      The MPXY8600 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.      This document offer customers to utilize Freescale MPXY8600 as transmitter and MC12311 as receiver to form 315MHz, 433.92MHz TPMS transmitter and receiver solution.

SOP Top Side Port Package_1369-01