Problem with analogWrite() on more than one pin

[espruino-discuss]

Posted at 2013-10-05 by Graham

Hi at all,

first of all thank you so much for this project (of cause I am a kickstarter baker).

Because I could not wait I ordered a olimexino-stm32 board and espruino worked like a charm.

But:

I am unable to get PWM working on two pins simultaneously.

// This works:
analogWrite(D37, 0.02, {freq:1000});

// This does not work:
analogWrite(D37, 0.02, {freq:1000});
analogWrite(D4, 0.02, {freq:1000});
// --> D4 keeps LOW

I am pretty sure this is a mistake on my part.

Many thanks and sorry for my english :-)

Graham

EDIT:
After two hours I found out, that it works with another pin combination, e.g. D37 and D36.
Probably it does not work with pins with ADC functionality?!

[gfwilliams]

Posted at 2013-10-06 by @gfwilliams

Hi Graham, you may just be unlucky... The STM32 has a bunch of timers, but not enough for each pin - so sometimes if you set one pin and it uses a timer that was in use by another, it gets reset.

I guess this is something that we could warn about with a little work...