Developing electronic circuits often feels like solving a puzzle. And solving this puzzle could win you a Multicomp Pro Tablet Oscilloscope!
And while finding the basic application to make an IC do its magic is often quite easy, some questions often remain.
Among the crucial skills of makers and engineers is interpreting a datasheet and this will come in very handy for the following puzzle:
This time we are looking at a staple of the 3d printing and CNC world: the TMC2130 stepper motor driver.
The photo and schematic show a basic circuit that allows the user to control the movement of a bipolar stepper motor with simple button pushes.
For practical reasons the built circuit has the enable pin(EN) pulled low to activate the circuit. The Arduino is only used to pass on 12V, 5V and GND to the tmc2130, it has not other connections to the circuit.
Pulling the DIR pin high or low determines the direction of the motor movement.
Pulsing the STEP pin makes the motor move.
But how far does the motor move?
The pins MS1, MS2,MS3 (also known as CFG0,CFG1,CFG2) determine the movement settings; the most widely used configuration is to pull all 3 of them low.
CFG2 determines where to get the voltage reference from. Low level sets it to internal.
The other two pins are much more interesting.
By pulling MS1/CFG0 and MS2/CGF1 low, we set the driver to "Full step," no interpolation and spreadcycle mode.
The most common stepper motors need to do 200 steps per revolution (1,8° angle change per full step).
So for a full rotation we need to press the step button 200 times.
So far so good.
Here is the puzzle:
What happens if you just leave MS1/CFG0 and MS2/CFG1 floating (open) -- how often would you have to push the STEP button for a full rotation?
Or do you think the motor would just not turn at all?
You can find the solution in theory and practice! We are interested in not only getting the answer right but in seeing the work you did to arrive at this answer.
Tell us if you tried you try it out practically (show us pictures). Or did you study datasheets or video tutorials (share the links you found helpful)?
The member who provides the best detail on how he or she solved the puzzle wins the prize!
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