8. Error codes

The adapter responds to some of the commands in Section 7 with an error code. The error code will either be zero to indicate success or it will be one of the following values:

Error code 1: Protocol error

This error code indicates that the command itself was invalid. Double check the bytes you are sending if you get this error.

Error code 3: Timeout

This error code indicates that the command took longer than the configurable I²C timeout period, so it was aborted. If this error or any of the other timeout errors occur, you might consider using the “Set I²C timeout” command to raise the timeout, which is 50 ms by default.

Error code 4: Timeout while sending address

This error code indicates that a timeout happened while transmitting the first byte of an I²C transfer, which contains the device address.

Error code 5: Timeout while transmitting

This error code indicates that a timeout happened while transmitting a data byte during an I²C write.

Error code 6: Timeout while receiving

This error code indicates that a timeout happened while receiving a data byte during an I²C read.

Error code 8: Target device did not respond

This error code indicates that the adapter received a NACK (Not Acknowledge) while transmitting the address byte to the I²C bus. This error can happen if the target device is not powered, if the target device is not properly connected to the I²C bus, or—for adapters that do not provide power to the bus—if the adapter’s VCC (IN) pin is not powered.

Error code 9: Received NACK for TX data

This error code indicates that the adapter received a NACK while transmitting a byte of data to the target I²C device.

Error code 10: Bus error

This error code indicates that the adapter detected an unexpected START or STOP condition on the I²C bus

Error code 11: Arbitration lost

This error code indicates that the adapter tried to send a high level on the I²C SDA line, but it detected a low level. This could happen if another I²C controller is connected to the same bus and initiates communication at the same time as the adapter.

Error code 13: Operation not supported

This error code indicates that the adapter recognized the command but it does not support it (e.g. due to lacking necessary hardware).