Tic T834 User I/O (Output)

I noticed that in the manual it says support for output might be added in the future and right now it is just an input.

(In the future, we might add commands allowing you to turn User I/O pins into outputs and drive them high or low.)

Supporting driving pins high/low would be very convenient for many small projects.

Hi.

Thanks for letting us know you are interested in being able to use some of the pins on the Tic as digital outputs. Can you share some specific applications you have in mind?

-Claire

Main application would be turning a logic level mosfet on and off to switch a larger load. Don’t expect much current out of the Tic but it would be helpful to have the output option available.

I’m interested in this feature as well. I’m controlling several motors and would love to be able to call a position, set a flag and get a output high from the T500 while the motor is in transit. My main device can get on with other jobs. I’d tie that User I/O to an interrupt pin on my main unit, and on H2L, clear my flag via an ISR. Then, when I’m ready, go check the status of the Tic and plan my next move.

You’re potentially already using a pair of your serial lines, so you’d need to be able to map the functions to any of the Tic’s four outputs (SDA, SCL, TX, RX).

Thinking aloud, Output Functions might include:

  • Transiting
  • AtFullSpeed
  • PulseOnTarget
  • AbruptHalt
  • PositionUnknown
  • VINBrownout
  • SpeedPWM (relative to your max)
  • PositionPWM (50% = 0)
  • CurrentPWM

Hi.

Thanks for the feedback. We are considering adding a scripting feature to our Tic controllers that would likely cover most of your cases by including a command for reading any of the Tic’s variables and another command for controlling I/O pins

-Claire

Hey! First time using Pololu products, and I’m very impressed so far! I’m using a tic 249 on a project, and I was wondering if the feature described here was ever implemented. I’ve got a small relay in the project that I’d love to be able to turn on/off via i2c commands through the tic.

Sorry for dredging up such an old thread, but it was relevant!

Hi, kebennett.

Thanks for chiming in to let us know you are also interested in a digital output feature! Unfortunately, we still do not have any timeline for when this kind of feature might be available. Feel free to continue bugging us about this, and if others area also interested, feel free to chime in too. More interest can only help push it higher on our to do list!

-Claire

1 Like

Hi,

I’m also interested in user i/o and scripting on the TIC, any word on when the update is coming out?

Hello, Andrew.

Unfortunately, we do not have any updates on when those features might be available.

Brandon

Hi guys,
Any news about this topic?

We use TIC36V to drive 4-axis robot and would like to avoid I2C overloading when moving.
I mean instead of asking/polling via I2C if the “current position” != “target position”, we could simply connect the dedicated pin to an I/O of the master. Then wait for the pin change, meaning the driver has finished the movement. That would be so much more efficient.

For reminder:
As stated here: Pololu - Tic Stepper Motor Controller User’s Guide

Pin function: User I/O

For now, the “User I/O” function is exactly the same as “User input”. (In the future, we might add commands allowing you to turn User I/O pins into outputs and drive them high or low.) This function is only available for the SCL, SDA, TX, and RX pins. The RC pin cannot be an output due to hardware limitations.

I am wondering if it would be possible that Pololu updates the Tic36V firmware allowing us to turn one I/O in output and drive it low (or high) while the driver is still busy producing steps.

I hope that makes sense to you and look forward to hearing from you soon.
Stephane

Hi, Stephane.

Thank you for your feedback; that sounds like a good feature that I hope won’t be too difficult to implement. I’ll look into it with my team and get back to you on it next week.

- Ben

Hi, Stephane.

If you contact us directly, we can get you a custom firmware version to try out with the feature you are requesting.

- Ben