I've built a quad using the Arducopter m2mPower ESCs from here:
I'm driving them with my own custom flight controller, and I'm wondering if anyone here might know the max PWM (input) rate these will support. I've asked 3D Robotics but haven't heard back so I'm hoping someone here might know. I'm currently running them at 50 Hz (with marginal results), but I keep hearing good things about running multicopter ESCs at rates up around 400 Hz. Anyone know what the default Arducopter PWM input rate is?
Thanks in advance,
The default is 400 I think, but I've tested them up to 490. And yes faster output = faster PWM and more control. A lot of folks don't believe that, but they don't take into account the large filter on the ESC PWM input, which adds a lot of delay. You can also flash these ESCs and remove the digital filter.
Thanks for your reply. Nice to know that those ESCs will handle the increased update rate. I'm currently pushing them at 100Hz, but I'm planning to change my FC to go higher. What firmware would you recommend?
Answered my own question: looks like these ESCs are similar (same?) as these:
and the SimonK firmware is reported to work nicely with them.
I noticed that for the quadrotor configuration, pin 1-4 output 490hz pwm signals, pin 5-6 output 50hz pwm, while pin 7-8 don't output any signal (always low). If I want to add one more channel to output 490 hz pwm, what changes should I make in the code?
In AP_MotorsHexa.cpp, what you did is to use a function, add_motor(), to regulate extra pwm output. But the problem for me is that I don't actually understand what meaning the function has and how to use it correctly..I didn't even find where the function is..
Thank you so much.
Without the SimonK firmware, increased input rates beyond a certain point will have little effect. This is because original airplane firmwares averages inputs to give you a smooth throttle control, Meaning that rapid input changes will not show up on the output. Heck, it even says so in the store product description.