how to switch TWI pins

[jacky]

Due to a hardware design error, the CLK/Data pins on TWI bus was switched in different PCB versions. I want use software to dynamically detect the situation and switch the pins. But the code doesn't work.  Could you help on this?

I am using 51822 and the SDK version is 9.0 and S110.

The following are related code:

uint8_t TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER=2;
uint8_t TWI_MASTER_CONFIG_DATA_PIN_NUMBER=1;

uint8_t who_am_i;

bool auto_correct_twi_pins()
{
twi_master_init();
mpu6050_register_read(REG_WHO_AM_I_Addr, &who_am_i, 1);
//if read correctly, who_am_i shall contains an valid WHOAMI ID.
if(who_am_i==Expected_who_am_I )
     return true;

//switch twi CLK and Data pin number
uint8_t tmp;
tmp = TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER;
TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER = TWI_MASTER_CONFIG_DATA_PIN_NUMBER;
TWI_MASTER_CONFIG_DATA_PIN_NUMBER = tmp;

twi_master_init();

//try again to verify the pin order is correct
mpu6050_register_read(REG_WHO_AM_I_Addr, &who_am_i, 1);
if(who_am_i != Expected_who_am_I)
      return false;
}
return true;
}

[Jørgen Holmefjord]

What is happening inside function twi_master_init? I do not see any calls to any TWI uninit functions. Are you getting any errors in the second twi_master_init call (NRF_ERROR_INVALID_STATE, etc.)?

[jacky]

Thank you for you reply.  I finally found my code works well. I thought it is not working because of the value of Expected_who_am_I was wrong.