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ESC not responding to full throttle range — Parallax Forums

ESC not responding to full throttle range

acannadyacannady Posts: 1
edited 2014-03-22 07:10 in General Discussion
Hello Everybody,

I am a student working on designing an autonomous quadcopter with a professor at my university. We have just started the project and we bought the ELEV-8 quadcopter kit to get started, we however did not buy the controller that comes with it. We have decided to use a Arduino uno that we could program ourselves. We have fully assembled the quadcopter and have some basic code put together and when we started testing our code we found that the motor would not respond until about half throttle. I was wondering if anyone would be able to help me with this problem? Has it happened to anyone else? I believe that the problem is with how I am calibrating the ESC in the first place or how I have it programmed. To help me solve this problem does anyone have the specs to the Gemfan 30A ESC that parallax sells?

Comments

  • User NameUser Name Posts: 1,451
    edited 2014-03-21 12:02
    Have you used a scope to look at the pulse you are generating? Does it have a 50 Hz repetition rate and an adjustable pulse width between 0.5 ms and 1.5 ms?

    BTW, a Propeller is the perfect device to use to generate precise signals of this sort. :)
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-03-21 12:43
    User Name wrote: »
    between 0.5 ms and 1.5 ms?

    I think your numbers are off by half millisecond. The pulse length should be between 1ms and 2ms. With 1.5 being the mid point.

    @acannady, How are you generating the pulse? Often ESC have sequence you need to go through to arm them. You should be able to get this to work with an Arduino but I agree with User Name's suggestion of using a Propeller.
  • User NameUser Name Posts: 1,451
    edited 2014-03-21 16:34
    Duane:

    You're right, of course. So is the code I've written. It's just my internal BioDRAM that is messed up. Refresh rate is too low or leakage current is too high.
  • Jack3Jack3 Posts: 55
    edited 2014-03-22 06:29
    This could be as simple as adjusting end-points(servo travel) in the transmitter. But, setting endpoint on speed control changes with the brand so address that first.
  • Ken GraceyKen Gracey Posts: 7,392
    edited 2014-03-22 07:10
    Boot up your ESC with the throttle at full-range. Counter-intuitive, I know. Then listen for two beeps, then set throttle to the lowest position. Now the ESC will have learned the full range - at least this is how it works with the ESCs we are using.

    Same process can be done with your Arduino.

    Ken Gracey
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