title: Protocols used to talk between an embedded CPU and a PC
body: <p>I am building a small device with its own CPU (AVR Mega8) that is supposed to connect to a PC. Assuming that the physical connection and passing of bytes has been accomplished, what would be the best protocol to use on top of those bytes? The computer needs to be able to set certain voltages on the device, and read back certain other voltages.</p>
  
  <p>At the moment, I am thinking a completely host-driven synchronous protocol: computer send requests, the embedded CPU answers. Any other ideas?</p>