Unkown Error in trying to initate PWM

Toit

#Unkown Error in trying to initate PWM

Thread channel in help

Alexx Kaos 12/19/2023 03:51 PM

HI guys, just trying to get set up with Toit right now. I've loaded up the example pwm script, but it's throwing an UNKNOWN ERROR 0x102(258).
I know the Pin is correct (it works with the basic standard led blink script), and is pwm compatible (from upython and arduino projects).

I'm using a seeed XIAO esp3-c3, GPIO#10

import gpio
import gpio.pwm

main:
  led := gpio.Pin 10
  generator := pwm.Pwm --frequency=50
  channel := generator.start led
  //channel.set-duty-factor 0.5
  sleep --ms=10_000
  channel.close
  generator.close
  led.close

And the monitor outputs:

[jaguar] INFO: program aecc3774-fdf7-fc6a-1e25-b3c397b6481f started
E (2734368) ledc: freq_hz=1000 duty_resolution=16

******************************************************************************
Decoding by

jag

, device has version <2.0.0-alpha.126>
******************************************************************************
EXCEPTION error.
UNKNOWN ERROR 0x102(258)
  0: pwm-init_                 <sdk>\gpio\pwm.toit:177:3
  1: Pwm                       <sdk>\gpio\pwm.toit:103:12
  2: main                      led_pwm.toit:6:16
******************************************************************************

[jaguar] ERROR: program aecc3774-fdf7-fc6a-1e25-b3c397b6481f stopped - exit code 1

(edited)

floitsch 12/19/2023 03:53 PM

We might be doing something wrong ok the C3...

floitsch 12/19/2023 03:57 PM

We are trying to find one, but we might only have them at the office ..

Alexx Kaos 12/19/2023 03:57 PM

Haha, I'm not surprised. I know using the fringe boards makes things like this harder. Thanks for the help

floitsch 12/19/2023 03:59 PM

I'm currently not at the computer but I will later look at the code and try to see if something obvious is wrong.(edited)

floitsch

I'm currently not at the computer but I will later look at the code and try to see if something obvious is wrong.(edited)

Alexx Kaos 12/19/2023 04:00 PM

Very cool, thank you. I'll play around with the BLE until then

Alexx Kaos 12/19/2023 06:28 PM

FYI, turning up the frequency to 10kHz got it working. For my use case I want to work in the 9-36Hz range, but I guess I can make that work with on/off timers and tasks.

floitsch 12/19/2023 06:29 PM

You should be able to handle 9-36hz in software. Yes

floitsch 12/19/2023 06:37 PM

What are you trying to drive with the pin?
Maybe there is another good way?

Alexx Kaos 12/19/2023 08:20 PM

Blinking LEDs. THe most basic of functions

(LEDs are 3W, so their being driven by a PNP transistor).

I wanted to use the PWM to have non-locking functions for BLE control (change frequency, brightness etc). I just discovered the tasks which seem like a slightly more advanced asyncio function from upython though, which may be able to handle my use case for now

floitsch 12/19/2023 08:21 PM

Why do you want to run it at such a low frequency?

floitsch

Why do you want to run it at such a low frequency?

Alexx Kaos 12/19/2023 10:05 PM

It's a flicker-light stimulation device for brain wave entrainment. The effective studied frequenceies are 9-36Hz.

floitsch 12/19/2023 10:06 PM

Ok. That makes more sense

floitsch 12/19/2023 10:07 PM

If you need very precise timings it might be worth looking whether the i2s can be run at this low speed.

floitsch 12/19/2023 10:07 PM

(probably not, but you worth checking).

floitsch

If you need very precise timings it might be worth looking whether the i2s can be run at this low speed.

Alexx Kaos 12/19/2023 10:11 PM

My guess is that the brain is too slow for that level of precision, we already have an auto-correcting 80ms 'synchronization window' of stimuli. But I'll explore that option if the first round of tests turns out promising.

16 messages in total