Test independent of your device.
Short SDA to ground and i2cdetect should report all addresses as present.
Short SCL to ground and i2cdetect should run very slowly (~1 sec per address) and nothing be detected.
Repeat on both sides of the voltage shifter.
If that is all working, then look at your device and why it isn't responding. Probing MCP23017's is fairly easy. Are they actually powered properly?
Short SDA to ground and i2cdetect should report all addresses as present.
Short SCL to ground and i2cdetect should run very slowly (~1 sec per address) and nothing be detected.
Repeat on both sides of the voltage shifter.
If that is all working, then look at your device and why it isn't responding. Probing MCP23017's is fairly easy. Are they actually powered properly?
Statistics: Posted by 6by9 — Thu Jun 27, 2024 8:55 am