Configuring I2C on FRDM-KL46Z

[amanjain]

I'm trying to establish communication between Micro-controller MKL46Z256VLL4 and Magnetometer chip present on-board MAG3110. I'm not able to get the desired values on the variables for xaxis, yaxis and zaxis from the Magnetometer chip. My code for reference-

#include "MKL46Z4.h"

void InitLEDR(void)

{

    SIM_SCGC5 = SIM_SCGC5 | SIM_SCGC5_PORTE_MASK; //clock to Port E for PTE29

    PORTE_PCR29 = 256; //Alternate 001 for bits 10, 9, 8 respectively

    GPIOE_PDDR = GPIOE_PDDR | (1u<<29);

}

void InitI2C(void)

{

    SIM_CLKDIV1 = SIM_CLKDIV1 | (1u<<17) | (1u<<16); //bus clock is 24/3 = 8MHz

    SIM_SCGC5 = SIM_SCGC5 | SIM_SCGC5_PORTE_MASK; //clock to PTE24 and PTE25 for I2C0

    SIM_SCGC4 = SIM_SCGC4 | SIM_SCGC4_I2C0_MASK; //clock to I2C0

    PORTE_PCR24 = PORTE_PCR24 | (1u<<10) & ~(1u<<9) | (1u<<8); //alternative 5 - 101 for bits 10, 9 8 respectively

    PORTE_PCR25 = PORTE_PCR25 | (1u<<10) & ~(1u<<9) | (1u<<8); //alternative 5 - 101 for bits 10, 9 8 respectively

    //I2C1_A1 = 0x01; //address when module acts as slave

    I2C0_F = 0x80; //mult=2h ICR=00h

    I2C0_C1 = 0xB0; //10110000 - module enable, interrupt disable, master, transmit,

    //acknowledge bit sent,repeated start off, wake up off, DMA off

    I2C0_C2 = 0x00;

}

//UART0,PTA1=RX and PTA1=TX

void InitUART(void)

{

    SIM_SOPT2=(1u<<26);//SIM_SOPT2_UART0SRC(1);Clock to UART0 MCGFLLCLK 20.97152MHz as MCG_C4=0x00 low range 20Mhz

    //SIM_SOPT5=0x00;kar na kar

    //open-drain mode disabled(Clear bit 16) plus

    //connection to UART_TX and UART_RX(Module to module interconnect) Clear bit 2,1 and 0

    SIM_SCGC4=SIM_SCGC4|(1u<<10);//set bit 10 for giving clock to UART0

    SIM_SCGC5=SIM_SCGC5_PORTA_MASK;//set bit 9 for giving clock to PORTA

    PORTA_PCR1=PORTA_PCR1&~(1u<<10)|(1u<<9)&~(1u<<8);//PTA1 as UART1_RX (010  9 for alternative 2 which is UART0_RX)

    PORTA_PCR2=PORTA_PCR1&~(1u<<10)|(1u<<9)&~(1u<<8);//PTA2 as UART1_RX (010  9 for alternative 2 which is UART0_TX)

    UART0_C2=0x00;//TX and RX both disabled

    UART0_BDH=0x00;//0x02;//Baud rate =9600,20.97152Mhz clock

    UART0_BDL=0x88;//BR=136//0x22;//BR=132.5=132=100111000

    UART0_C1=0x00;

    //UART0_S2=UART0_S1 & 0xC1;

    UART0_C3=0x00;

    UART0_C4=0x0F;//OSR=15//OSR=3

    UART0_C5=0x00;//not both edges 0x02;//as OSR=4, sampling on both edges of baud rate clock of received data

    UART0_C2=UART0_C2 | (1u<<3);//only TX enable

}

void WriteToI2C(unsigned char data)

{

    while(!(I2C0_S & 0x80));

    I2C0_D = data;

}

void SetMag(void)

{

    WriteToI2C(0x0E); //device ID

    WriteToI2C(0x11); //register address - C2

    WriteToI2C(0xB0); //10110000 Magnetic Reset, raw data and auto reset enabled

    WriteToI2C(0x0E); //device ID

    WriteToI2C(0x10); //register address - C1

    WriteToI2C(0x01); //AC=1 all other 0

}

void UART_OutChar(unsigned char data)

{

    while(!(UART0_S1 & (1u<<7)));

    UART0_D=data;

}

void UART_OutUDec(unsigned int n)

{

    unsigned cnt=0;

    unsigned char buffer[50];

    do

    {

        buffer[cnt] = n%10;// digit

        n = n/10;

        cnt++;

    }    while(n);// repeat until n==0

    do

    {

        UART_OutChar(buffer[cnt-1]+'0');

        cnt--;

    }while(cnt != 0);

}

unsigned int ReadMag(unsigned char reg)

{

    I2C0_C1 = 0xB0; //10110000 - module enable, interrupt disable, master, transmit

    WriteToI2C(0x0E); //Device ID

    WriteToI2C(reg); //Register

    I2C0_C1 = 0xB4; //10110000 - module enable, interrupt disable, master, transmit,

    //acknowledge bit sent,repeated start on, wake up off, DMA off

    WriteToI2C(0x8E); //Device ID + 1(=Read)

    I2C0_C1 = 0xA0; //10100000 - module enable, interrupt disable, master, receive

    while(!(I2C0_S & 0x80)); //wait till transfer is complete

    return (I2C0_D);

}

int main(void)

{

    InitI2C();

    InitUART();

    InitLEDR();

    SetMag();

    int i;

    unsigned int xread, yread, zread;

    while(1)

    {

        i=10000;

        xread=ReadMag(0x01);

        yread=ReadMag(0x03);

        zread=ReadMag(0x05);

        UART_OutUDec(xread);

        UART_OutUDec(yread);

        UART_OutUDec(zread);

        GPIOE_PTOR = GPIOE_PTOR | (1u<<29);

        while(i>0)

        {

            i--;

        }

    }

    return 0;

}

[kerryzhou]

Hi Aman Jain,

    Please refer to the sample code of FRDM-KL46, there has an sample code for MAG3100.

  Please download the sample code from this link:

http://cache.nxp.com/files/32bit/software/KL46_SC.exe?fpsp=1&WT_TYPE=Lab%20and%20Test%20Software&WT_...

   Then after you install it, you will find the code in folder:kinetis_kl46_sc\kinetis_kl46_sc_rev2\klxx-sc-baremetal\build\iar\FRDMKL46_Demo

Wish it helps you!

If you still have question, please contact with me!

Have a great day,

Jingjing

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[amanjain]

Hi,

I am using KDS V3.0. I'm not sure how to open the file and which file will be opened to view the code.

[kerryzhou · Accepted solution]

Hi Aman Jain,

     The sample code which I recommend your just have IAR, Codewarrior project, and don't have the KDS project.

     You can download a Codewarrior 10.6 to open it, or you can just refer to the source code and add it to your KDS project.

     The picture which you give me is the IAR project, the CW project folder is :\kinetis_kl46_sc\kinetis_kl46_sc_rev2\klxx-sc-baremetal\build\cw\FRDMKL46_Demo\kl46_FRDMKL46_Demo

     If you want to refer to the source code, you can find it from folder: kinetis_kl46_sc\kinetis_kl46_sc_rev2\klxx-sc-baremetal\src\projects\FRDMKL46_Demo

Wish it helps you!

If you still have question, please contact with me!

Have a great day,

Jingjing

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

[amanjain]

Hi,

I'm able to get some values from the magnetometer, but it is a constant value. How do I calibrate it so that I can use it to judge my orientation. The board moves on the back of a door, so the axis on which 'g' is acting remains unchanged.

[mjbcswitzerland]

Hi

For KL46 there is also the option to try

http://www.utasker.com/kinetis/FRDM-KL46Z.html

which supports various accelerometer sensors in non-blocking maximum-speed I2C polling or interrupt modes, as well as I2c and accelerometer simulation.

No IDE restrictions since it works with CW, KDS, IAR, uVision, Green Hills, Atollic, Crossworks CooCox, GCC, Visual Studio.

Rather than example code it is a ready to use industrially proven solution.

Regards

Mark

Kinetis: http://www.utasker.com/kinetis.html

I2C: http://www.utasker.com/docs/uTasker/uTaskerIIC.PDF

KL46: http://www.utasker.com/kinetis/FRDM-KL46Z.html / http://www.utasker.com/kinetis/TWR-KL46Z48M.html

For the complete "out-of-the-box" Kinetis experience and faster time to market