Hi, I have a system with multiple AVRs connected via radio tranceivers using SPI. I've configured one as master, and the others as slave, and have a problem with the algorithm and the SPI. the algorithm is basically this:
Master transmits byte.
If recieved byte is correct (slave polls for byte from master), slave transmits confirmation byte.
Else slave does nothing (Doesn't transmit)
However I've read that the master must initiate all data transmissions, and this is a problem since, the slave needs to recieve the byte, check if its correct, and then either transmit nothing (since multiple slaves are connected via radio transceivers), or transmit a confirmation byte - but how can it do this if the slave can't initiate a transmission?
What's the proper way to accomplish this using SPI? (The circuit is already built, so it must be SPI and no other serial interface).