Legal Removal Request

Post: Hello Phil Can you try testing each IO Pi board individually without anything else connected to the Raspberry Pi? Try using the [b]"sudo i2cdetect -y 1"[/b] command to check that each IO chip is appearing on the I2C bus. If the IO Pis are only being used as inputs, the current shouldn't be a problem as each chip will only be using a few milliamps at most. They only use larger currents when the IO pins are set as outputs and even then, each chip can only supply a maximum of 125mA so that shouldn't cause an issue on the Raspberry Pi’s 5V rail. Do the inputs on the IO Pi share a common ground with the rest of the Raspberry Pi? If the inputs are being supplied from a separate power supply and the grounds are not connected, then that could damage the IO Pi chips as the potential difference between the two power supplies could be larger than 5V. The only other thing I can think of that could damage the IO Pi chips is if one of the stepper motors or relays doesn’t have a reverse protection diode fitted and is causing large voltage spikes on the power supply when they are being switched on or off. If you have an oscilloscope or multimeter with a max voltage setting it may be worth measuring the power supply to make sure there are no voltage spikes.