nuclear@5: commands
nuclear@5: --------
nuclear@5:  e<0|1> - echo on/off
nuclear@5:  p - start programming
nuclear@5:  b - boot
nuclear@5:  a<addr> - address offset to read/write data
nuclear@5:  w<value> - write value and increment address
nuclear@5:  r - read value and decrement address. response: OK <value>
nuclear@5: 
nuclear@5: All commands and responses are newline-terminated. On success the response
nuclear@5: starts with "OK", otherwise it starts with "ERR".