I would like to minimize the processor time in arduino and googled some ppm encoder stuff. I found that the parallax propeller has multi core architecture with eight 32-bit risc cores. That device is commonly used as servo controller, but I would like to use it in opposite. Has anybody done something like that?

I was thinking about reading the channels and writing the pulse time to register, wich could be read with for example via I2C.

There are some old blog posts about this: http://diydrones.com/profiles/blogs/multichannel-rc-servo-signal

Examples about communication protocols for parallax propeller can be found on web.

Ps. Also the same controller could be used for driving the servos. If using 7 independent input channels/timers, the output can be done by the eight timer. So the input pulses can be with any freq or order and the output can run in another freq.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • I have a receiver object for the Prop that will read 8 RC channels in any order at 1us resolution and write the results to main RAM, and it runs in one core.  You could use two cores to read 16 channels, if you had a need for that many.  From there you'd just need to write the I2C communication to slave it to another processor, which wouldn't be terribly difficult.

    There's also a Prop object that uses a single core to output up to 32 servos at 1us resolution at 50Hz.  I've modified it to output 8 outputs at about 250Hz - again, using a single core.  You don't need to use hardware timers if you write things like this in assembly, and there are enough cores to do this work and much more, in parallel, so you don't have to deal with interrupts.  It's very good at this kind of work.

    Jason

This reply was deleted.

Activity

DIY Robocars via Twitter
RT @chr1sa: Donkeycar 4.4 released with tons of new features, including path learning (useful with GPS outdoors), better Web and Lidar supp…
Nov 27, 2022
DIY Robocars via Twitter
RT @NXP: We are already biting our nails in anticipation of the #NXPCupEMEA challenge! 😉 Did you know there are great cash prizes to be won…
Nov 24, 2022
DIY Robocars via Twitter
RT @gclue_akira: レースまであと3日。今回のコースは激ムズかも。あと一歩 #jetracer https://t.co/GKcEjImQ3t
Nov 24, 2022
DIY Robocars via Twitter
UC Berkeley's DIY robocar program https://roar.berkeley.edu/
Nov 24, 2022
DIY Robocars via Twitter
RT @chr1sa: The next @DIYRobocars autonomous car race at @circuitlaunch will be on Sat, Dec 10. Thrills, spills and a Brazilian BBQ. Fun…
Nov 24, 2022
DIY Robocars via Twitter
RT @arthiak_tc: Donkey car platform ... Still training uses behavioral cloning #TCXpo #diyrobocar @OttawaAVGroup https://t.co/PHBYwlFlnE
Nov 20, 2022
DIY Robocars via Twitter
RT @emurmur77: Points for style. @donkeycar racing in @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video. https://t.co/Y2hMyj1…
Nov 20, 2022
DIY Robocars via Twitter
RT @SmallpixelCar: Going to @diyrobocars race at @UCSDJacobs https://t.co/Rrf9vDJ8TJ
Nov 8, 2022
DIY Robocars via Twitter
RT @SmallpixelCar: Race @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video. https://t.co/kK686Hb9Ej
Nov 8, 2022
DIY Robocars via Twitter
RT @PiWarsRobotics: Presenting: the Hacky Racers Robotic Racing Series in collaboration with #PiWars. Find out more and register your inter…
Oct 23, 2022
DIY Robocars via Twitter
RT @Hacky_Racers: There will be three classes at this event: A4, A2, and Hacky Racer! A4 and A2 are based around UK paper sizing and existi…
Oct 23, 2022
DIY Robocars via Twitter
Oct 23, 2022
DIY Robocars via Twitter
Oct 19, 2022
DIY Robocars via Twitter
Oct 18, 2022
DIY Robocars via Twitter
RT @NeaveEng: Calling all UK based folks interested in @diyrobocars, @f1tenth, @donkey_car, and similar robot racing competitions! @hacky_r…
Oct 13, 2022
DIY Robocars via Twitter
RT @araffin2: 🏎️ After hours of video editing, I'm happy to share a best of my Twitch videos on learning to race with RL. 🏎️ Each part is…
Oct 13, 2022
More…