No Output

[matjspalding]

I have my chip connected, it is recognised on address 20 via i2cdetect. The Code seems to run ok however I am not getting a response from the attached LED.

The LED and resistor are both OK as they work when directly connected. Other devices on I2c work OK.

Any Suggestions. I'm using a Pi4 and a MCP23017.

Thanks

[niabassey]

Sorry for the late reply for just in case someone else runs into this, one quirk I noticed with the MCP23008 and MCP23017 may show up on an address scan even if the reset pin is floating but usually won't operate.

That said, try pulling reset high.