help to understanding Firmata EchoString example

Hello i look into this example and i have some question, i know the firmata is not for the rookies but the example really small and easy...but not work to me.. yet :)

  • why start the example this variable? (byte analogPin;) this analogPin not used in this sketch

  • can i use the arduino serial monitor to communicate to the firmata? When i open the monitor the board immediatly send for me the following: ùðy if i try to send any string or char no response, no echo (of course the monintor speed changed to 57600)

  • what is this STRING_DATA i look around here ( and too) and there is no info, the only string is FIRMATA_STRING


Having the same problem.

I use Duemilanove with ATMega 328, ide 0023 and EchoString example sketch. Right after switching i have on the serial (57600):


Tried to change baud rate to 9600 both in serial monitor and sketch, but no changes:


Absolutely no ideas(

After viewing Firmata lib sources it’s clear that it’s ok. The board sends data back using Firmata protocol. It sends back START_SYSEX command byte which is 0xF0 (


) and then versions information.

So, it is not human-readable and one should use Processing Firmata sketch on the host to parse responses according to Firmata protocol.
Best regards.

can i use the arduino serial monitor to communicate to the firmata?

If you knew what to type, and could enter binary data, yes. Of course, the serial monitor does not support sending binary data, so that part alone leaves the serial monitor out.