Is using PWM on pins 3,9,10,11 along with an IR receiver possible?

Projects General Guidance
1

Hi!

I want to implement a small Nano-based RGBW (RGB+white) LED controller with IR remote. After having read that the PWM on pins 5 and 6 is slightly impaired, I opted for the other PWM pins: 3, 9, 10, 11. They work perfectly, as long as I don't add the IR functionality. Pin 9 and 10 remain unaffected, but pin 11 and 3 start to respond erratically to AnalogWrite, and after that, the IR receiver also ceases to work. I've tried the receiver on other pins, no difference. Just calling enableIRIn and then an AnalogWrite is enough to reproduce the problem.

I'm absolutely beginner with Arduino and microcontrollers in general (have received my very first board yesterday), but I suspect that it has something to do with the fact that these pins use Timer2, and so does IRLib.

Any ideas? It would be very cool to be able to use 4 full-valued and identically behaving PWM outputs along with IR receiving capability...

Source is attached - the hardware setup is pretty straightforward.

TriggerTheProblem.ino (233 Bytes)

2

Have you tried using pins 5, 6, 9, 10 for the LEDs. Then timer 2 ( pins 2, 3) is not used for analogWrite.
TimerPWMCheatsheet

3

groundfungus:
Have you tried using pins 5, 6, 9, 10 for the LEDs. Then timer 2 ( pins 2, 3) is not used for analogWrite.
TimerPWMCheatsheet

Yes, I have. They are not affected by this problem, but have their own:

"The PWM outputs generated on pins 5 and 6 will have higher-than-expected duty cycles. This is because of interactions with the millis() and delay() functions, which share the same internal timer used to generate those PWM outputs. This will be noticed mostly on low duty-cycle settings (e.g 0 - 10) and may result in a value of 0 not fully turning off the output on pins 5 and 6."

If possible (with reasonable effort), I'd like to use the 4 PWM channels with identical characteristics.

4

Found a possible workaround: the IRrecvPCI class doesn't use any timer, and so leaves all the PWM channels usable. I'll have to see if it actually works for my project...