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Topic: 200hz PWM signal to control camera gimbal tilt - paid gig (Read 966 times) previous topic - next topic

defiant12

I'm a mechanical type of guy and don't have any microcontroller experience at all. We have a small little camera gimbal we would like to hack and control with standard RC PWM. However, a friend of mine looked at the control input signal with a scope and we can clearly see that while the control signal looks like your standard PWM, its at a 200z refresh rate.

Plugging in a typical RC PWM receiver or RC PWM generator at ~50hz gets no response.

After looking at the PCB and wiring, we're pretty confident that there are no proprietary protocols going on between the factory controller and the gimbal. It's just doing it at 200hz and ignoring standard 50hz.

So. I need some help either programming a small Arduino or creating some other type of circuit that will accept 50hz RC PWM in, and then translate that to 200hz out.

The only other possible step might be that we could need 3.3v 200hz signal on the out vs the standard 5v RC voltages. Its clear when we scoped it that the true control signal was 3.3v, 200hz, 1000-2000ms PWM. We could get lucky and 5v will work fine, but if not, then we need 3.3.

Anyone interested in working on this? I'm in the LA/Orange County, CA area if you want to get your hands on the gimbal hardware. Otherwise we can do this remotely.

Thanks for looking!

CrossRoads

Code: [Select]
|____|----|____|----|____|----|____|----|  200 Hz, 5mS period, 2500uS High/2500uS Low at 50%
|___________________|-------------------|  50 Hz,  period 20mS period, 10,000uS High/10,000uS Low at 50%


Code will need to measure offset from 50/50 of 50Hz, and adjust ratio same amount in 200Hz.
This means there will be some lag from input to output change, perhaps 2 or 3 cycles of the 50Hz input. (60mS).
Seems like a straightforward enough task of measurement, calculation, and output using Blink Without Delay.


Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Mr_arduino

I have sent a PM to defiant12.

CrossRoads

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Mr_arduino

I apologize for any confusion that I may have caused. I was referring to defiant12. I have edited my previous post to clarify this.

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