Problem with I2C1

[sapan]

Hi,

I am having problem while using I2C1. I have connected MPU6000 on I2C1. I am using I2C scanner to determine on which address sensor is connected.

I2C config Part:

Code: Select all

static const I2CConfig i2cfg1 = {
    OPMODE_I2C,
    400000,
    STD_DUTY_CYCLE,
};

void I2CInitialize(void){
  i2cInit();

 i2cStart(&I2CD1, &i2cfg1);

 // Link PB8 and PB9 to I2C1 function
 palSetPadMode(GPIOB, 8,  PAL_MODE_ALTERNATE(4));// 
 palSetPadMode(GPIOB, 9,  PAL_MODE_ALTERNATE(4));// 
 // startups. Pauses added just to be safe
 chThdSleepMilliseconds(100);*/
}

I2C Scanner Function:

Code: Select all

void i2c_scanner1(void){
   uint8_t x = 0, txbuf[2],rxbuf[2];
   int32_t messages = 0;

   chprintf((BaseChannel *)&SD1,"inside i2c1 scanner");
   for(x=0;x<128;x++){

      txbuf[0] = 0x00;
      txbuf[1] = 0x00;

       messages = i2cMasterTransmit(&I2CD1, x, txbuf, 2, rxbuf, 0);
       if(messages == 0)chprintf((BaseChannel *)&SD1, "I2C1: Sensor is available on Address: %x \r\n", x, messages);
      chThdSleepMilliseconds(1);
      }
   chThdSleepMilliseconds(1000);
}

I have used this function for I2C3 and it works perfectly fine. Returns address on which sensors are connected.
While doing same for I2C1 program get stuck at this point: while ((dp->SR2 & I2C_SR2_BUSY) || (dp->CR1 & I2C_CR1_STOP))

How to fix this?

Sapan

[Giovanni]

Could it be an electrical problem? (conflicts, pull-ups etc)

Giovanni

[sapan]

I am trying it on discovery board and its not giving clock on PB8. Do I need to change DMA priority or do i need to do something in initialization part? Will check for connection once again

[barthess]

Do I need to change DMA priority

First try some more trivial steps. For example, ensure that you correctly initialize pins for this I2C cell.

[sapan]

Have initialize I2C pins and checking whether clock is coming or not. Any other way to ensure correct initialization?

[Giovanni]

What ChibiOS version are you using, 2.4.0 had a bug related to I2C1 using alternate DMA channels.

Giovanni

[sapan]

I am using 2.4.0

[Giovanni]

Well, try the 2.4.1 just in case you are hitting that bug.

Giovanni

[sapan]

Same issue with 2.4.1. How can I check whether port initialization is correct??

[Giovanni]

Are you using a STM32F4-Discovery board? if so, PA9 is not available because it is connected to VBUS.

Giovanni