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teemuatlut / TMC2130Stepper

Arduino library for Trinamic TMC2130 Stepper driver
MIT License
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Is DIR pin obsolete? / verify current fraction of steps / 1 step function in SPI #97

Closed Er9y714 closed 3 years ago

Er9y714 commented 3 years ago

When using driver.begin(); function, I suppose the driver is connected via SPI. Then we do not need DIR pin. I verified this by not connecting the pin to anywhere. driver.shaft_dir(0); still changes the direction.

In this case what is the point of using DIR_PIN in this line? TMC2130Stepper driver = TMC2130Stepper(EN_PIN, DIR_PIN, STEP_PIN, CS_PIN, MOSI_PIN, MISO_PIN, SCK_PIN);

When I remove the DIR_PIN (to save a pin on the board), the function does not work of course.

My first question is, if I will use SPI connection, how can I not use DIR_PIN for this function? I do not want to waste a pin that is not being used.

Second question is, is there a way to know where the step is in terms of fractions (instead of counting from the start)? Imagine I advance step by step (each step is 1/8 step) and after 3 steps I would like to check what the fraction it is standing.

Is there an SPI function for 1 step advancing instead of setting STEP_PIN as HIGH and then LOW?

Thanks!

teemuatlut commented 3 years ago

Basically yes, it's obsolete and the library doesn't do anything else with it other than setting it as an output. I had some plans to use the step, dir and en pins but there are better libraries to handle the step generation. I also moved to developing a new library with new architecture and the unnecessary pins were dropped from the API.

You can read current microstep counter with .MSCNT().

To take a single microstep you'll have to use the max 256 microstep setting.

Er9y714 commented 3 years ago

Wow thank you for prompt response!

I have come across with that library but I did not know they were different. Because I have spent so much time to figure this library out, I do not think I will try other libraries. It is silent while holding the motor, I can adjust the microstep setting by software and it works :).

It seems I will not be able to use the step function because of 256 limitation.

Have a nice evening!