I am running a ramps 1.4 with pololu 4988 stepper drivers the question i have is i am trying to run a torch height controller that wires in between the ramps and the pololu driver it uses the stepand dir wires…but the problem is the thc uses a constant ground and pulses the 5 volt signal to the step and dir pins…I have read thru the 4988 maunal but can’t find whether these can work with a 5 volt logic signal going into the step,dir and enable pins i am thinking the ramps would control the ground side not the 5 volt side?I can invert the signals to high enable for these pins or low enable but the thc is only able to give a 5 volt signal to them… So i need to make things work with what the thc is doing if possible?
The A4988 accepts 5V and 3.3V logic signals. You can see more about the logic supply voltage range accepted by the A4988 inside its datasheet, which can be found under the “Resources” tab of its product page.
As for getting your RAMPS kit to work with your torch height controller, I recommend posting about that on the RepRap Forum or other 3D printing forums, which should have a bigger community of people who are much more familiar with the RAMPS kit (which we do not manufacture).
Thanks for the response i did manage to find the info as far as what it needs to make the pololu stepper driver work and i also found what was causing my issue.It seems that by using wires to connect the pololu to the board i was getting interference so i ran shielded wires and took care of the issue now i am working on making a pcb to go between the ramps 1.4 and the pololu stepper driver to better eliminate the possibility of interference …