The device is powered up by setting RTS and DTR high on the
host. After a few milliseconds the microcontroller is up and running.
During powerup the output pins of the microcontroller are not yet stable. This gives some
garbage on the RXD line of the host. So clear the input fifo on the host, a few
milliseconds after setting RTS and DTR high.
Next the host must send a character 'I' and a character 'R' with at least a 500
microsecond delay in between.
The microntroller responds with sending the characters 'O' and 'K'.
Now the initialization is done and the microcontroller will start sending decoded
infrared-trains to the host from this point on.
Once the device is initialized, the microcontroller sends 6
bytes to the host, every time a decodable infrared pulsetrain comes in from the infrared
receiver. These 6 bytes are pseudorandom, but constant for every specific key on a remote.