Hey guys, I have a little problem on a new board comunicating with a MPU9250 sensor.
- Chip version is nrf52832-QFAA-BA
- GPIO PINS Used P0.20 (SDA) and P0.21 (SCL)
- I can read the sensor WHO_AM_I register correctly (it returns 0x71).
- I can't write on register, function twi_master_transfer returns always false.
Here my TWI macro functions to read and to write:
bool readI2cData(unsigned char address, unsigned char reg, unsigned char len, unsigned char * data)
{
// Write: register address we want to start reading from
if (twi_master_transfer(address<<1, ®, 1, TWI_DONT_ISSUE_STOP))
{
// Read: the number of bytes requested.
if (twi_master_transfer(address<<1 | TWI_READ_BIT, data, len, TWI_ISSUE_STOP))
{
// Read succeeded.
return true;
}
}
// read or write failed.
return false;
}
uint8_t readI2cReg(uint8_t address, uint8_t reg){
unsigned char data;
if (readI2cData(address, reg,1, &data))
{
return data;
}
return 0;
}
bool writeI2cReg(unsigned char address, unsigned char reg, unsigned char len, const unsigned char value)
{
uint8_t data[2];
data[0] = reg;
data[1] = value;
// Write: register protocol
if (twi_master_transfer(address << 1 , data, len,1))
{
return true;
}
// read or write failed.
return false;
}
And here is what I try to write:
unsigned char data[6];
/* Reset device. */
data[0] = BIT_RESET; //equal to 0x80
if (i2c_write(st.hw->addr, st.reg->pwr_mgmt_1, 1, data))
return -1;
delay_ms(100);
/* Wake up chip. */
data[0] = 0x00;
if (i2c_write(st.hw->addr, st.reg->pwr_mgmt_1, 1, data))
return -1;
Where am I wrong? Probably missing something?
Thanks.
