Hi!
I am working on a project which requires stepper motors to be driven at high speeds like 5000 steps/sec and AccelStepper (AccelStepper) Class documentation discourages use of setSpeed() function for speeds more than 1000 steps/sec setSpeed() documentation
Does anyone have some suggestion on how I can still use AccelStepper and Arduino (or in fact any other library for Arduino) for this purpose or should I move to Raspberry Pi/some industrial stepper controller?
Assuming (because you have not told us) that you have a stepper driver that takes step and direction signals then it is easy to write your own code to operate the motor without any library.
Have a look at this Simple Stepper Code
And for "roll-your-own" acceleration have a look at this (Reply #7)
It would probably also be a good idea to use the digitalWriteFast library for that bit of extra performance.
...R
or should I move to Raspberry Pi/some industrial stepper controller?
Well the Raspberry Pi will not do because Linux is not real time and so trying to output such a fast signal will have lots of stuttering in the output.
You can use a Teensy 3.2 (Arduino compatible) and the TeensyStep library. This gives you up to 300000 stp/sec on multiple motors. Accelerated and synchronised movement.
TeensyStep: GitHub - luni64/TeensyStep: Fast Stepper Motor Library for Teensy boards
Teensy 3.2: Teensy® 3.2
and here a short video showing the performance: TeensyStep High Speed Stepper Library - YouTube
That looks promising.
Problem is that the stepper driver is expecting to see 5 volts, any recommendations for a level shifter that will work fast enough for this?
Great job on the library!
Fats
Problem is that the stepper driver is expecting to see 5 volts,
No it is not, I don't think you understand stepping motors.
If the motor says 5V then that combined with the resistance of the coil tells you the current. You do not get this current by applying 5V, you get this current by applying a large voltage, say 24V and using a chopping regulator to limit the average maximum current deliverer.
This over voltage allows the current to get into the coil faster and so the motor develops more toque and so can move faster.
any recommendations for a level shifter that will work fast enough for this?
You need a proper motor driver, not the toy one you appear to have.
Thanks!
Fats
Problem is that the stepper driver is expecting to see 5 volts, any recommendations for a level shifter that will work fast enough for this?
In case you are using those small drivers like a DRV8825 or a A4988 -> they are directly compatible to 3.3V outputs so no need to level-shift. In case you use one of those larger optocoupled drivers like a Leadshine DM556 or similar you can try if it works directly with 3.3V (it usually does for me) but this is somehow borderline.
I usually use one of the 74HCTXXX buffers for level shifting from 3.3V to 5V. They are pretty fast (~10ns transfer time), cheap, available in breadboard friendly DIP housing and readily available.
E.g. the [74HCT125](https://octopart.com/search?q=74HCT125&start=0&specs2.20.values=Through Hole) has 4 buffers, the [74HCT245](https://octopart.com/search?q=74HCT245&start=0&specs2.20.values=Through Hole) 8 buffers. You get them for about 50 ct.
Here some more information on interfacing 3.3V Arduinos to 5V optocoupled stepper drivers.
Thank you, I will check out your links.
Fats