Need a low frequency (can preset at each value of 15Hz to 25Hz) PWM signal

Thanks for going through the code and making the mods.

Alas, I've loaded it up and it has the same problem as the version I last added to the forum - it does compile fine BUT there is absolutely no signal output on pin 9 (as per my previous forum entry and in the sketch headlines on STATUS).

To check that my Arduino circuit wiring has not gone awry, I re-loaded the code I wrote for 30.5Hz. It worked fine - oscilloscope shows ~30Hz signal and able to change the duty cycle in range 15% to 85% by adjusting the pot. LED changes brightness as I change the pot.

So, this new version with a lower frequency may compile but there is still something not right with the code. I've looked through your latest version and can't see an obvious error. I can't now determine whether its a simple line error in the text or the code structure itself isn't suitable.

If you have any ideas on where the error lies, that would be most helpful.