Power Shield Question

Hardware
1

I want to use the Photon in conjunction with stepper motors. I have everything working correctly, but the stepper motors need more power than what the Photon outputs in order to have the necessary force. I’m kind of a newbie to all this and am not sure of the best route forward.

I need to power the Photon, but yet have more voltage to move the steppers carrying a load. Would the Power Shield https://docs.particle.io/datasheets/photon-shields/#power-shield allow me to do this?

Thanks in advance for your insight!

2

@pattersonc, because of their high current (and possibly higher voltage) demands, steppers cannot be controlled directly from Photon GPIO pins which can only provide 20ma at 3.3v. This is a limitation of the STM32 processor used on the Photon and not a lack of power on the board. So the Power Shield would not help.

What you want to look at is a stepper motor driver board like this assortment from Pololu:

These boards have two supplies - logic and stepper. The logic side can be powered from the 3.3v pin on the Photon while you provide a separate supply for the motors, which can vary from 3v to 12v or more depending on your steppers.

If you don’t want to use a driver board, you will need to use high current drivers (transistors) between the Photon pin and the motor inputs. The board is easiest to implement.

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3

Thanks for your quick and thorough response. I do appreciate it.

I’m currently using this Drok Stepper Driver to make it work. I’m wondering if these drivers will still meet my need. Perhaps I can try the 12 volt power option on the driver and see if it provides me with more force needed. (The last image on the Amazon page shows the layout, one with 12 volt option). Maybe I just need a bigger battery and try the 12v option. If so that will be good news.

I’ll keep investigating… and thanks again for your insight.

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@pattersonc, what stepper motors are you using? If they are not rated for 12v operation you will simply burn them out. Selecting steppers with the desired torque is always a good idea :wink:

5

Thanks again for the pointers and info… appreciate it.

I’m doing some testing and have NEMA 14, 17, & 23 that’s I’m experimenting with. I will be mindful to investigate the voltage ratings so as to no burn them out! Definitely don’t want that happening.

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