An additional stepper motor is required to move the pen up and down. For that purpose, a small 28BYJ48 should be enough:
Imax = 200 mA
To learn how A4988 driver works, here is a good explanation:
As per this explanation and documentation, VRef x 2 = Imax
Therefore VRef should be set to 0.100 V. Done.
Now the mechanics and electronics are ready:
And we can proceed with the first test, with a ball pen:
Imax = 200 mA
To learn how A4988 driver works, here is a good explanation:
As per this explanation and documentation, VRef x 2 = Imax
Therefore VRef should be set to 0.100 V. Done.
Now the mechanics and electronics are ready:
And we can proceed with the first test, with a ball pen:
