Software i2c in Positron

[tolyan249]

I have the same situation. I received an MLX90614 sensor, and when I scan the address=5A, it doesn't show the temperature with this address. However, when I set the address to =0, everything works as expected.


This was given to me by GPTCHAT

The situation where an MLX0614 sensor starts showing temperature readings when a request is sent to address 0 is indeed encountered and typically indicates a configuration or communication issue.


Why this happens

By default, the MLX0614 is configured with the address 0x5A (90 in decimal). Address 0 in the I2C protocol is not used for slave devices – it's a special "General Call" address that is typically employed for addressing the bus master's own internal registers (e.g., for reading/writing configuration) or for broadcasting to all devices that support it.


When you send a request with address 0, the sensor reacts in a special way: it ignores its own configured device address and begins transmitting data. As a result, you might actually receive a correct temperature value.