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PWM for Servo

Hi there,

what would be a simple and inexpensive method to generate a PWM signal for driving a little servo? Any suggestions?

The cheapest http://www.arduino.cc/ you can find will have PWM signals, and soooo much more.

Thanks, but actually I thought about something to control from vvvv.

Regards,
Sven

You can use the arduino as a stand alone or as an io interface for vvvv.

Utilizing the ArduinoFirmata-Plugin I presume?
If so, how do I set, which of the digital outputs acts as the PWM generator?

Ah… just realized that it’s being set from within the plugin, nice.

Still I need to upload a script to my Arduino that handles the servo commands the right way. Tried to do so by using the provided example (yes, I did exchange the library as stated in the vvvv help file before) but it failed to compile on my Diecemila.
Unfortunatelly the Firmata topic seems to be a rather complex one with many outdated software revisions and links to be found. Any help or up-to-date links to tutorials?

hi i would use arduino as well and its pwm or the motor shield for arduino which has control for sevo stepper and DC , if you want eeven cheaper there are some microncontroller tiny ones for a few euros but you will have a hard work to program and do the cicuit . you can send receive data from arduino to control the servo . if you take the arduino option i,ll give you a hand with the code and patches if you need. bests

Thanks for your nice offer, colorsound - I might come back to that later! For now I would just like to control a simple pwm via vvvv but I just don’t know, how to get this started. None of the examples seem to compile on my interface.

To give an example: I tried to upload “StandardFirmata” from Arduino’s Example Library (v. 1.0.1) but it states “‘TOTAL_PINS’ was not declared in this scope”, highlighting “byte pinConfigTOTAL_PINS;” within the code. What does that mean? Is it related to the specific board version I’m using?

Ok, found the problem. The current Firmata examples that come with Arduino 1.0.1 won’t compile with the library of version 2.0.
So which Arduino built will work? Regarding the fact, that vvvv’s Firmata Plugin is from 2010 it must be from this year I guess.

Tried v21 and and succeeded. End of monologue.

why not simply send the commands serial to the arduino make a serial.read there, do the stuff you want on the arduino with the values and send out the PWN with the arduino?

Interesting thought, but apparently Firmata works like a charme. Does everything I needed.

good for you :-) I did a project with processing using the arduino directly out of processing and it was very buggy but I was using the ArduinoMega, only a few PWM Channels where working, shiftregisters where not working aswell because of timing issues… .

arduino firmata 2010 ?
have you noticed vvvv.org/contribution/arduino-firmata-2.2-plugins

I noticed that, but according to the description this is a beta test version only (“A Version 1.0 pre-release pack for the unpatient”), so I thought it’s safer to use the Plugin that comes with the current official Addon Pack. Also I don’t have an Arduino Uno, so no need to upgrade. So far everything seems to work fine.

the old plugin is definetely more beta than the new ;)

the new plugin works not just with the uno. as stated in the description, the firmata encoder and decoder plugins are hardware independent. in the end, firmata is just a protocol (like OSC or MIDI) which can be used with arduino via serial port but also with whatever hardware you like.

with beta28, the old addonpack plugin will be replaced by the new one.

something went wrong, its not yet part of the addon pack 28. keep using the contribution for now.