问题 Dear stack overflow users, I have built a device with a master device, and a network of 10 slaves. All of them communicate via 4 wire SPI. Right now I am writing the program for both boards, and they don't seem to be working, I do not get expected responses. I have a master board, and 10 of identical slave boards. The protocol is simple - as with SPI any transaction is initiated by the master device, and a command is sent. The selected slave then receives aforemetioned command, sets a busy