Stacking 4 Stepper Motor hats to control 8 stepper motors

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Mechblak
 
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Stacking 4 Stepper Motor hats to control 8 stepper motors

Post by Mechblak »

I am trying to control 8 stepper motors on 4 Hats with a Raspberry Pi 4. Will I be able to stack that many Hats on the Raspberry Pi 4? Also how would the power supply work between the 4 hats, will I have to have an individual power supply per 2 Hats(so 2 power supplies total)?

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Re: Stacking 4 Stepper Motor hats to control 8 stepper motor

Post by adafruit_support_bill »

You can stack 4 HATs.. You will need to give them all unique addresses. Addressing is covered in the guide. https://learn.adafruit.com/adafruit-dc- ... -1097209-3

You will need one or more power supplies capable of supplying enough total power for all 8 of your motors. You will also need to choose motors that are compatible with the drivers on the HATs. Note that the drivers do not have current limiting, so motors that are designed for use with current limiting drivers are not going to work.
https://learn.adafruit.com/all-about-st ... he-stepper

One limitation you are likely to run into with that many motors is motor speed. Since communication with the HAT is via i2c, the total combined step rate for all motors will be limited by the speed of the i2c bus.

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Mechblak
 
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Re: Stacking 4 Stepper Motor hats to control 8 stepper motor

Post by Mechblak »

Thank you for the response I will look into that. I would like to address that not all 8 motors will be operating at once. Only 1 motor max will be operated.

"One limitation you are likely to run into with that many motors is motor speed. Since communication with the HAT is via i2c, the total combined step rate for all motors will be limited by the speed of the i2c bus."

Addressing your comment above, since only 1 motor will be operating at a given time, will motor speed still be an issue?

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Re: Stacking 4 Stepper Motor hats to control 8 stepper motor

Post by adafruit_support_bill »

If only one motor is moving at a time, it will have full use of the i2c bus.

What motor speeds are you looking to achieve?

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Mechblak
 
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Re: Stacking 4 Stepper Motor hats to control 8 stepper motor

Post by Mechblak »

I'm don't have certain speeds that I need. For some background information, I'm designing a automated test bench and a portion of that test bench is to turn and push knobs on a display using stepper motors. I will be running through a python script that will push/turn these knobs sequentially so only one motor will be used at a time. The knobs require some initial force to activate, do you have an idea if any stepper motor would work or would I need a specific one? Would the Stepper motor - NEMA-17 size - 200 steps/rev, 12V 350mA on your website be compatible with the drivers on the HAT? Thank you

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Re: Stacking 4 Stepper Motor hats to control 8 stepper motor

Post by adafruit_support_bill »

The knobs require some initial force to activate,
Stepper motors have more torque at lower speeds. So they are a good choice for that application.
Would the Stepper motor - NEMA-17 size - 200 steps/rev, 12V 350mA on your website be compatible with the drivers on the HAT?
The #324 motor in the store is a good match for the HAT. https://www.adafruit.com/product/324

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Re: Stacking 4 Stepper Motor hats to control 8 stepper motor

Post by Mechblak »

Thanks for your help!

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