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firmata / arduino

Firmata firmware for Arduino
GNU Lesser General Public License v2.1
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2.4 spurious data #185

Closed MrYsLab closed 9 years ago

MrYsLab commented 9 years ago

2.3 does not exhibit this problem. PyMata is receiving a spurious stream of unsolicited data at startup that is crashing the client. No commands have been sent to Firmata. Data is received as single bytes and is formatted here with the word data followed by b and then the byte data.

data b'\xe0' data b'S' data b'\x02' data b'\xe1' data b'9' data b'\x02' data b'\xe2' data b'\x00' data b'\x00' data b'\xe3' data b'\x05' data b'\x04' data b'\xe4' data b'j' data b'\x03' data b'\xe5' data b'd' data b'\x02' data b'\xe6' data b'\x00' data b'\x00' data b'\xe7' data b'\x00' data b'\x00' data b'\xe8' data b'\x00' data b'\x00' data b'\xe9' data b'\x00' data b'\x00' data b'\xea' data b'\x00' data b'\x00' data b'\xeb' data b'\x00' data b'\x00'

soundanalogous commented 9 years ago

Nothing has changed in Firmata.cpp since 2.3.6 that would impact startup code. Did you happen to load StandardFirmataYun rather than StandardFirmata by chance or are you using your own skech?

soundanalogous commented 9 years ago

It actually looks like noise is being picked up on your analog pins. e0 (ANALOG_MESSAGE) is analog pin 1, e1 is analog pin 2, etc. Do you have analog pin reporting enabled by default for all analog pins? That could produce noise on any analog pins that are not attached to a sensor or other device or minimally a resistor. It's difficult for me to diagnose what the cause is without more info.

soundanalogous commented 9 years ago

Figured it out. Here's the root of the issue you're experiencing: https://github.com/firmata/arduino/blob/master/examples/StandardFirmata/StandardFirmata.ino#L352-L355. This is new as of Firmata 2.4.

The problem is that when all analog pins are set to ANALOG input in the systemResetCallback (which is called initially at the end of the setup function), the analog pins are read an reported. This will essentially report noise for any unconnected analog pin. I'll need to suppress this line from being called when systemResetCallback is called by setting a flag before the default analog input is set and clearing it after. Then check that flag when reportAnalogCallback is called with a value parameter of 1.

MrYsLab commented 9 years ago

Great work thanks!

soundanalogous commented 9 years ago

This issue also affects ConfigurableFirmata but a fix for this issue in the configurable branch is not so simple because of the way features are split among separate classes.

soundanalogous commented 9 years ago

@MrYsLab This should be fixed now for StandardFirmata and StandardFirmataYun. Please sync with the master branch and let me know if you still encounter the issue. I'll cut a new release once verified.

MrYsLab commented 9 years ago

@soundanalogous Works like a champ! Thanks for fixing this so quickly.