MicroPython Forum (Archive)

The first thing that comes to mind is I suspect that filtering at the frequency at which the ticks occur is not going to be helpful. The noise is coming from the very fast rise- and/or fall-time of the tick itself, or perhaps the tick is a switching artifact from having some noise on the signals dri...

It's worth pointing out that with PPM you can get as many channels as the transmitter puts out, even with a low channel-count receiver, because the PPM signal has everything on it even if the receiver can't drive that many servos.

Well, the really super-cheap R/C units for low-end toys don't have proportional control. But if the receiver has outputs for driving a standard R/C servo, it is likely to have a PPM signal inside it even if it isn't brought out. Way back in the 1960's when proportional, multi-channel R/C was created...

So an R/C PPM decoder was actually quick and easy to get going. I'm using a Spektrum AR7700 receiver which has direct PPM out, but on many if not most R/C receivers it is easy to find the PPM signal and bring it out. I tested this code with a cheap 5 channel transmitter. (And by tested, I mean after...

Yes, for just two PyBoards, a UART link is much simpler. It is multi-drop where CAN gets interesting.

Thanks for the reference code. There is no doubt an Arduino library, too, if I went googling for it. So I guess since the IC timer callback runs at interrupt priority it should give reasonably accurate timings. 4 uSec accuracy would be 1 bit in an 8 bit int, if memory serves. (1mSec / 250) I was ima...

Has anyone written a library to decode the pulse train from a standard R/C receiver? I want to set up some kind of simple tele-operation interface for a mostly-autonomous robot. So a simple solution would be to decode the pulse train from an R/C receiver. Ideally, picking up the signal before it is ...

@dbc Interesting, that had never occurred to me. To someone ignorant of CAN, what advantages does this have over simply using a UART? Well, there are plusses and minuses. A multi-drop bus with RS-485 is relatively easy to get going if the UART peripheral supports "9-bit mode" -- that is using the 9...

just get another PyBoard and use CAN bus like many vehicles do? Indeed. A few months back, before I got distracted by other aspects of life, I worked through the CAN tutorials and was able to get two PyBoards to blink each other's LEDs over the CAN bus. The prototype just has a couple of TI CAN XCV...

pythoncoder wrote: I've made an attempt at tackling the points raised and would welcome further comments.

Excellent. IMHO you can declare victory at this point.