Could you add aREADME.adoc file and accompanying wiring diagram, similar to that found in other examples, e.g. seethe NeoPixel ring example.

Nice PIO example 🙂
Just a couple of queries: a) the comments talk about "IRQ4", but the code seems to be using relative IRQs? b) is there a reason for using relative IRQs, or would it make sense to use an absolute IRQ so that a single ServoTrigger could be used for multiple Servos?

I will add a readme.

Regarding IRQs: Sharing the IRQ did not work, so I used relative IRQs.
That way, the Trigger needs to be the SM before the output program, so the IRQs match.

Regarding IRQs: Sharing the IRQ did not work, so I used relative IRQs.
That way, the Trigger needs to be the SM before the output program, so the IRQs match.

Sounds like this should be in the README! :)

Regarding IRQs: Sharing the IRQ did not work, so I used relative IRQs.

I hope you don't mind, but I had a bit of a fiddle.... 😉 (I'm still getting to grips with PIO myself)

I was able to get it working with only a singleServo_Trigger object by changingservo_trigger() to do:

    irq(clear, 4)         # Clear IRQ4, allows servo code to run again    irq(4)                # Set IRQ4 again, ready for the wait in servo code

(which I guess then means I need to change the trig_ctr calculation totrig_ctr = (trig_frq // 1000 * trig_target) - 4), and changingservo_prog() to do:

    wait(0, "irq", 4) .side(0) # Wait here for IRQ to be released by trigger SM

😀

Other comments:

• As this is purely an example, it might be more useful to change thefor _ in range(2): towhile True: ?
• IMHO theServo_Trigger class ought to be renamedServoTrigger (which is the typical Python convention)
• Given the wide variability of servos, it's probably worth addingmin_pulse andmax_pulse arguments to yourServo init-method, and then doing

self.base_pulse = min_pulseself.free_pulse = max_pulse - min_pulse

But of course these are only suggestions, I'll leave the final decision up to you.

I don't mind - I'll check your suggestions later. During my testing, the 1-Trigger 2-Servo code compiled, but the output was garbage.

Thanks! The replacement with IRQ/Clear + Wait did work.

When testing the changes that I mentioned above, I had three separate servos all running from a single trigger :) But I had to insert some sleeps between moving each servo individually, because if I tried moving multiple servos at the same time, it tried to pull too much current from my computer's USB port and the Pico reset. (this is fixable by powering the servos from a separate PSU, but I couldn't be bothered to wire that up!)