what are the performance implications of using arduio-pico compared to micropython and the official c sdk

[gregorianrants]

i dont have a lot of experience with microcontollers and am looking for a platform to start with.
i am fairly experienced with physical computing on raspberry pi though.

arduino is attractive because there are a lot of resources
pico has impressive specs including 2 cores.
which to choose.

i am wondering does this library give us native c performance (or close to it)?
or is there something about the way it works that means it is not as fast?
if it has native c performance with the ability to use the arduino libraries and learning resources then its a no brainer.
i do robotics so i will be doing real time stuff such as controlling motors with encoders so performance is important.
i have heard the micropython is not up to high speed real time stuff and dont really want to go down the pio route just yet.
would love to use 1 core for reading counting ticks on encoder and do everything else in another core.

[earlephilhower]

I suggest you benchmark a few things if you're really concerned. If you don't use FreeRTOS everything here should be comparable to bare metal C, but Python on a RP2350/RP2040 may be good enough and REPL does make it easy to experiment.

FWIW the PIO encoders may be a solved problem, check the pico-example repo. No need to dedicate an entire core to the task if there's anything else it could be doing.

[gregorianrants]

thanks for your answer, it will help me decide what route to go down.

[gregorianrants]

i have been trying to figure out how i would use the pico-example for pio encoder

looking through your docs it says

"A complete copy of the Raspberry Pi Pico SDK is included with the Arduino core, and all functions in the core are available inside the standard link libraries."

I take it that means i could use the example you have given from arduino ide if using arduino-pico

[earlephilhower]

If you rewrite it as a sketch, sure. The pico-examples are set up as a single standalone app (i.e. main vs setup and loop) and probably has compilation sequences to get the .H from the .PIO as part of cmake. It's not complicated, but it's not cut-n-paste. If you have no experience with the SDK you might do better to see if someone has pushed it into an Arduino library...

[gregorianrants]

ah okay, thats good to know that its not too complicated, i can focus of getting some basics down just now, with the knowledge that this could be an option, when i need it.

already have my eye on this as a potential candidate
https://docs.arduino.cc/libraries/rp2040-encoder-library/