Yes, the code is in C, compiled on the computer and transfered to flash memory on the chip.
Its a little difficult to get a good curve going with such low resolution input. I choose the default values to put most of the steps below the 50% mark precisely so that most of the control would be at low speed. The last two steps take you to 75 and 100%
There are several possibilities for improving control. One would be to ramp the power level from step to step, so instead of a sudden jump from 50 to 75, you’d get a quarter or half second or so ramp. This would smooth out the bumps a bit, but I don’t know how noticable it would be. Might make it a little easier to avoid swapping ends at the high end.
I’d also like to improve the PWM frequency, currently it uses a 100Hz pulse frequency (thats what causes the buzzing you hear when the SE moves). The next software version of this mod is going to bump that frequency up to something much higher, which should quiet it down considerably.
Another option is to give it control of the reverse circuit too, then remap all but one of the reverse speeds to forward speeds, resulting in higher resolution propo (maybe 8 or 9 steps) for the forward circuit, which, IMO, is much more useful than reverse.
.
