Tic use case question

Support Servo controllers and servos
1

Hi,

I am a plastics designer, i.e. I have little electronics experience, pls be nice :wink:

I am prototyping some lab equipment which ideally would use a button press to trigger a stepper/leadscrew to send a gantry down (Fwd) to an endstop and then retreat (Rev) to a home position.

Could I use a Tic to do this without an additional micro controller? After going through the guide I would be looking at this set up.

Setup
1.Use Fwd and Rev endstops.
2. Set auto homing reverse.
3. Have the Tic in analogue position mode, with the post scaler set very high.
4. Fake an Fwd analogue input with a button.

Action

  1. Button press triggers analouge position Fwd,
  2. The gantry hits the Fwd endstop.
  3. The Gantry then auto homes to the Rev endstop.

This would allow me to control positioning entirely with the endstops, which is within my skillset and will be far easier for the end users to control if adjustment is needed.

Am I bending the Tic to the wrong use here, or is there a better pololu product for this?
Am I understanding the analouge use correctly, or is there a better way to give the system a simple “run fwd a long way” command that does not involve coding?

2

Hello.

There are a couple ways you could set something like that up without the need for a separate microcontroller. Since you have a limit switch at both ends of your gantry, you might consider configuring the Tic for analog speed control mode. That would allow you to simplify it so when the button is pressed the Tic moves the motor forward at a set speed until it hits the forward limit switch and when the button is released, it will move it in reverse at a set speed until it hits the reverse limit switch. If you don’t want to hold the button, you could use a latching button or switch. You can find more information about the analog speed control mode in the “Setting up analog speed control” section of the Tic user’s guide.

Brandon