Hello I am i have connected an MCP23S17 spi GPIO expansion, upon testing it with the sample code from here, It does not seem to work. There could be many reasons why this is happening. I would like to narrow down the possible culprits. I would like to first know if my raspberry pi can detect the spi device. Is there an equivalent command for spi that detects if a device is present? Kind of like a ping request in networking.