AvrSerial: enable double speed for more reliable communication
AvrSerial: enable double speed for more reliable communication

johnkingsley/aprinter,johnkingsley/aprinter,ambrop72/aprinter,johnkingsley/aprinter,fixator/aprinter,fixator/aprinter,ambrop72/aprinter,ambrop72/aprinter,johnkingsley/aprinter,ambrop72/aprinter,johnkingsley/aprinter,fixator/aprinter,fixator/aprinter,ambrop72/aprinter,johnkingsley/aprinter,fixator/aprinter,fixator/aprinter,ambrop72/aprinter,ambrop72/aprinter,johnkingsley/aprinter