In message , mick
writes
I also considered using a PIC chip as those will work down to 2v. It
would be possible to use software PWM to drive a LED output MOSFET and an
analogue input from a "brightness" control. The problem is efficiency -
it probably isn't very... ;-) One of the little 8-leg chips like 12F683
would be the animal.
Why use software PWM when that chip has it in hardware? Trivial to set
up and control with a pot. I reckon you could buy the chip and a capable
transistor cheaper than the equivalent non micro components needed to do
PWM.
--
Clint Sharp