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What kind of signals does hoverfly sport sends to ESCs — Parallax Forums

What kind of signals does hoverfly sport sends to ESCs

ShivamShivam Posts: 5
edited 2015-01-05 09:29 in General Discussion
I would like to remove the hoverfly sport board form my ELEV-8 quadcopter in-order to automate it. I would like to Know that what kind of signals does hoverfly sport board sends to the Electronic speed controllers (ESCs)

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2015-01-05 01:43
    The HoverFly Sport sends pulses to the ESCs which are very similar to those used to control servos.

    These are the same type of pulses being send from your radio receiver to the HoverFly Sport (as mentioned by xanadu).
    xanadu wrote: »
    Have you tried feeding it standard pulses using a standard servo object?

    Shouldn't be any different than the code you use to move a servo, am I missing something?

    The main difference between the pulses used to control ESCs and those used to control servos if the refresh rate. Many ESCs can accept refresh rates greater than 50Hz. I don't know the refresh rate used by the HoverFly Sport but I'd think normal servos pulses would be a good starting point.

    You could use the object discussed in this thread to monitor the pulse lengths of these pulses. You'd need a different program to check the frequency of the pulses.
  • trangertranger Posts: 179
    edited 2015-01-05 03:29
    Shivam wrote: »
    I would like to remove the hoverfly sport board form my ELEV-8 quadcopter in-order to automate it. I would like to Know that what kind of signals does hoverfly sport board sends to the Electronic speed controllers (ESCs)

    I don't know the frequency used by the Hoverfly firmware, but the frequency used by Jason Dorie's firmware on the same controller is 250 hz. Here is a comment from Servo8Fast.spin:

    "''*****************************************************************
    '' Control up to 8-Servos Version3 03-08-2006
    ''*****************************************************************
    '' Coded by Beau Schwabe (Parallax) and Jason Dorie
    ''
    '' This is the standard Servo32 driver modified to support a 250Hz
    '' output rate for use with Quad/Hexa/Octo Copters
    ''*****************************************************************"

    The output is a 5V pulse with a width that varies between 1000 and 2000 microseconds.

    -Russ
  • Duane DegnDuane Degn Posts: 10,588
    edited 2015-01-05 08:43
    tranger wrote: »
    The output is a 5V pulse with a width that varies between 1000 and 2000 microseconds.

    Russ is correct about the HoverFly Sport using 5V pulses but I've used a variety of ESCs and they all worked with 3.3V logic. If/when I get around to making my own 'copter control board, I don't plan to use level shifters since they would interfere with the ability to program the ESCs from the same connection.

    Shivam, In case you missed it, the Open Propeller Project #4 was an effort to use the Propeller in place of a programming card. Most ESC could be programmed from the Propeller with a direct connection to the I/O pin. A few ESCs required a pull-up resistor on the line when programming the ESC.
  • xanaduxanadu Posts: 3,347
    edited 2015-01-05 09:29
    I guess I was missing something when I posted that lol. I didn't feel much difference between 50hz and 400hz on my small quads but it does make sense to run them faster than standard servo pulses.

    The Propeller ESC programmer is great! I had often thought about writing one because I never used a programming card. There's nothing like trying to manipulate the controller, juggle the wiring and instruction manual and being timed all at once. The SimonK ESC firmware seems like the best bet for a multicopter ESC though. Maybe when you run out of standard ESC you can ship them pre-flashed with SimonK.
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