ESP32 Forum

Hi

I am using the ESP32 function i2c_master_cmd_begin() as:

err = i2c_master_cmd_begin(I2C_NUM_0, cmd, 1000 / portTICK_RATE_MS);

and every now and then this function returns -1 (which is an error).

Would there be a reason for this to happen?

thanks,

From what I can read, this indicates an 'ACK error'. I think this means the slave did not acknowledge the I2C request, but I'm not entirely sure.