Lois

Hello,

I recently bought an ESC and motor from hobby king (Turnigy TrackStar Waterproof 1 10 Brushless Power System 5200KV 80A)
Now I followed the instructions to calibrate the ESC and the LEDs indicated that the calibration was completed.
The PWM signal I'm sending to the ESC has a width of 2000us (max) 900us(min) 1500(middle position) over a frequentie from 500Hz.
Now I want to let the motor turn slow but it doesn't seem to work. The motor is fully on or fully off.

Can anyone explain to me why this is happening? I have the feeling the calibration is correct, but the speed of the motor is still not manageable. Who can help me solve this?

Dave H

Creating a control signal with a non dedicated RC controller? Like a arduino or similar?

If I'm following correctly, using a 500Hz sampling frequency results in time resolution of 2000μs. Right in the range of the desired control signal widths. If so this doesn't appear to provide enough resolution for smooth progressive response.

Does the time between pulses remain constant? What time are you using? Frame rate is the term frequently used in RC. Traditional RC use is 20ms, but many modern items can go quicker, ~5ms or even less for some.

What voltage are the pulses at?

Lois

I'm using something simular to an arduino. It's a different microcontroller, but the principle is the same.
The time between the pulses is always constant, since they are commited to the set frequency (500Hz). I checked this with a scope. The voltage from the pulses are around 3V.
After calibrating the ESC I put a max pulsewidth of 2000us on the ESC which makes it turn. When I change the pulsewidth with steps of 1us it goes off when I reach 1600us. In the meantime the motor didn't turn any slower. It's the exact same when I start from the other side (700us + steps of 1us), but then it just turns the other way (which is expected)

Dave H

Ah OK. Try lowering the 500Hz to say the traditional 50Hz (20ms) to start. I'm guessing there is not enough off time between pulses. If that works you should be able to work it back up some or even quite a bit. What model ESC? Also never hurts to try reversing the long and short order, that sometimes clears up issues.

A couple images for reference. Some variation should be accepted by the ESC calibration process.

Lois

Thank you for your reply, I'm using an 1/10 80A ESC from trackstar. I will try configuring it with 50Hz and smaller pulses. Theoretically it should work when the off time is how big? I worked with a PWM signel from 5%, so that's a pretty long off time. I will set up the 50Hz tomorrow morning. I will let you know how it went.