ArduinoFirmata Plugin - number of analog outputs for using MicroServos

Hello,

I thought it would be possible with vvvv to control six Arduino MicroServos independently with the ArduinoFirmata plugin. I use the tinkerkit sensor shield, but at the six analog output pins only five motors respond (PWM). And only four outputs are with varied data, the remaining is playing synchronous.

Is this the pre-condition (of the Arduino/the plugin) or is it possible to get five or six of the outputs with varied data?
The power situation of the arduino UNO seems to be sufficient for playing at least five motors simultanously. Has somebody an idea?

Thanks sueniii

hey i dont know much about the tinker kit sensor shield. However, firmata is nice but also has its limits and as long as you dont want to dive into the plugin code you would rely on the developer (jens.a.e. i think)

I recommend checking out how to control the arduino directly via serial and r232 node.

a good starting point is west’s arduino paper touch interface in which he published the basic neccesary arduino code and vvvv patches.

cheers.

hi!

it’s me, the “developer” ;) actually, firmata itself is not limited on the amount of servos you can drive; the board(s) is/are. one can drive up to 12 servos without any extra shield with the servo library (which the firmata arduino firmwares use) - see http://arduino.cc/en/Reference/Servo
also the tinker kit sensor shield does nothing special - it just wires the O0 to O5 pins on the shields through to the PWM pins 3,5,6,9,10 & 11. note that a servo can be driven not just from a PWM pin, but e.g. from pins 2 to 13 on a standard arduino, like the UNO or Leonardo.

can you provide your patch please? that would be good. i have had cases driven 6 servos with the firmata plugin already and it should be possible without doing all the other patching work + defining your own protocol, etc. so i am more than happy to help getting this working.

i also did a quick test and it was successful. did you set the pin mode to SERVO? i guess so, but just to be certain…

gr!j;

ps. attached a barebones firmata patch for driving 6 servos on the tinkerkit sensor shield (aka the PWM pins)

six_firmata_servos.v4p (12.7 kB)

pps. one might consider using an external power supply when driven that much servos. voltage/current spikes from the servos cause the board to reset, which again results in some funny behavior on the comport…