Single limit switch for forward and reverse

Support Motor controllers/drivers and motors
1

Hi. I’m using a 36v4 to drive a stepper that turns a telescope dome. As such I only need one limit switch to find home and then my code decides the shortest way to home and sends the dome forwards or reverse depending on the shortest distance. Therefore it does not matter which way it goes the homing switch is in the same place. Can I attach one side of the switch to both the SCL and SDA/AN pins and the other side to the GND pin so that the single switch triggers both the forward and reverse limits. I’m using the limit switch to reset the calibration of the dome rotation not to prevent movement of the dome.

2

Hello.

Unfortunately, the Tic does not support using a single limit switch like you described. If you connected to the SCL and SDA/AN pins as a forward and reverse limit switch, they would get toggled at the same time and the Tic would not allow the stepper motor to move in either direction. If you have space to add a second limit switch and use one for forward and one for reverse, that would work; otherwise, you could use the single limit switch as either a forward or reverse limit switch and home in that direction every time.

Brandon

3

Thanks for the reply. It’s a shame that you can’t set a single pin as a limit switch for both directions. It seems that the controller is designed purely for linear applications such as 3d printers and not for rotary ones. I would have thought it would be a useful option for many

4

I too ran into this problem and totally agree with Tim. This is a product very much for linear applications. Thought the TIC was the easy solution to my design… RC input, limit switches, homing, can connect it to a micro if I chose to, and everything else I was looking for. Read the manual and it was unclear if i could use this for rotary applications and just assumed it was the perfect fit. If I used 2 limit switches I would like it to be able to home in both directions and then center between the 2. So now I have to choose between 2 limit switches or home to center, the other options is to spend more time and use a microcontroller and make my own.

With all of the other very impressive features, rotary operation was very much overlooked. I still think the TIC is an amazing product and will probably use it in other projects.