Sharing the LED pin on Moteino with PWM output

[donaldhwong]

I needed 4 PWM pins.

Moteino uses 9,10,11.  Out of the three, the only one I dare to try is #9, the LED pin.

My question is will the PWM output on the LED pin result in less signal effectiveness.  If yes, which pin, anyone would recommend? I do have to use the RFM69 for signal input at the same time.

Thank you,
Donald

[Felix]

According to the basic laws of EE, this is not a matter of "signal" (voltage), but rather of current.
If you PWM pin 9, there will be 3.3V on that pin (or whatever the MCU operating voltage is, for Moteino it's 3.3V).
Moteino (atmega) pins can source around 20mA of current. The LED connected to D9 (through a 1.5k resistor) will eat 2mA of that.
If it were a 20mA LED there would not be a lot of current left to source from D9.

For your purposes, if you just want to see a PWM "signal" that drives something else, depending on what that target expects in terms of current, you should have plenty from D9. The LED will still PWM along as well. If you want to completely remove the LED from the scenario just sever one of the traces leading to it, preferrably in a spot where you could solder bridge it again if later needed.

[donaldhwong]

Ok, worth a try and see what happens.  Thank you.

You can put [solved] in my subject line as always.