Suggestion on how to run 5 Stepper Motors from a Photon?

General
1

I am trying to create an information bar chart using 5 stepper motors, but they will not need to be run simultaneously. That said, they will probably each need an interrupt switch so they can be calibrated. Any suggestions on setup/products would be greatly appreciated. THANKS!

2

What power requirements will these steppers have? Will more than one stepper ever need to move at the same time? I’m thinking that if not, then you might be able to use one driver for all 5 steppers along with some kind of switch that would control which stepper is connected to the driver.

3

Thanks @Ric - they should not need more than 5v and only one would need to move at a time. I like your solution. Thanks so much!

4

@Ric - that said, do you have any suggestions for the switch I could use?

5

@jpalay you may be able to use a Pololu board and supply a serial input from the Photon. Micro Maestro 6-Channel USB Servo Controller. The website has examples of how to use with an Arduino. I don’t have one with me to try it on a Photon but they make them with up to 24 channels. Look at the resources tab for additional information.

6

You could use N muxes where N is the number of control lines for your stepper motor (usually 4?)

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7

@harrisonhjones - thanks for the suggestion by I am not sure how that would work? I can see maybe using a mux to to turn different servos on and wire them all in serial…Is that what you were thinking? Thanks again, Josh

8

Well, it really depends:

  1. Are we talking about servos or stepper motors?
  2. If we are talking about servos it depends on the type of servos. Some servos maintain their position after their input is lost. If you are using these kind of servos you can hook a single servo output to the mux’s input and then up to 8 servos to the outputs of the mux (assuming an 8 channel mux). You’d then cycle through the various outputs to control the 8 servos.
  3. If we are talking about stepper motors it depends on how much holding torque you need. When steppers aren’t energized they have very little holding torque so a mux might not make any sense. If you just need position control with no holding torque the mux approach would work.

I personally would just suggest a I2C servo/stepper controller which would allow you to chain the controllers and control many servos/steppers at one.

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