Hello everybody. My first post.
I'm trying to motorize my diy wooden "star tracker". I did everything just like on this site: http://fstop138.berrange.com/2014/01/building-an-barn-door-mount-part-1-arduino-stepper-motor-control/
It' s working, but I can't fine tune the rpm of the motor.
So now I connected this small 28BYJ-48 stepper with 1:64 gear and i have changed it to run Halfstep. But it didn't change anything.
I still can't fine tune rpm. The motor must turn 4 times every 60 second - to follow the moving stars. I can tune it to run 4 turnes in 59 sec or 61 sec, but not 60 sec.
A few examples:
I'm changing the stepper.setSpeed value with 1 unit but the rpm are not changing every time. From setSpeed 300 to setSpeed 279 the rpm are the same.
stepper.setSpeed - seconds
310 - 53 sec. 300 - 59 sec. 280 - 59 sec. 279 - 59 sec. 278 - 61 sec.
So I need the setSpeed somewhere between 279 and 278 to hit the 60 seconds. 278.5 doesn't work.
Could someone tell me how to fix that?