Basic stamp and electronic speed controller (ESC)

Balrin

I have some code that I originally wrote to controller the Parallax servo (which works great) and then grabbed a traxxas servo and tested it there (again works great). Now, and from the same RC car as I got the Traxxas servo, I'm trying to control the ESC. All I get is wide open reverse and the range that original would fully move the servo full range seems to have no effect at all.

Any thoughts on what I could be doing wrong or what else I may need to add to my circuit or code to fix this?

Thanks,
Brian

allanlane5

Some ESC's do 'off' at 1.5 mSec pulse width, 'reverse' at 1 mSec pulse width, and 'forward' at 2 mSec pulse width. For that to work, you DO have to have a good signal, and a good ground.

Have you connected the BS2's 'ground' (Vss) signal to the ESC?

Balrin

The ESC is providing the power for my stamp. This ESC is setup to have the batteries directly connected to it and then through the black/red/white wire it provided the power to the RF receiver. So I'm using this same idea to power my stamp. So in short they share a common ground. I also wired in an LCD to debug some things on my project and the values are at least what I expected.

I'm pretty sure these ESCs are using PWM to control the speed. Anyways, the only way I could get any change in frequency was to add larger and larger delays in between each pulsout, but I'm thinking that is only because after you don't pulse out for long enough time the ESC stops the motor.

Just some speculation on my side, I don't know what I'm doing or wouldn't need help [noparse]:D[/noparse]

If the numbers below were true for this ESC then I would expect the RF receiver would have to be pulsing different lengths to control the steering vs the drive motors. I guess this is possible but seems like a bad design. I'll try putting the ESC into the steering output of the original receiver and see if it gets crazy or acts normal. I did try increasing my pulse widths though from around 1100 or whatever I found the servo extent to be to 3000 and still wide open reverse was all I ever saw. It's almost like any pulse is giving me wide open reverse and then no pulse shuts it off....just not making sense [noparse]:([/noparse]

Brian

Balrin

I take that back, I want to say I ended up creating a debug loop and tried pulsing from 0 to 3000. I then recall trying to add some delay between pulses and then as I mentioned earlier (I think) as the delays go large enough the motor would slow down but only because I think I was creating my own PWM :P
Also, it was still only reverse and technically when I get this worked out I don't even want reverse, just forward hehe.

Brian