I am creating a robot with my Raspberry Pi 3 B+. For my project, I wish to use 2x NEMA 17 stepper motors for moving around, and 2x SG90 servos for managing pan/tilt of the head.

I already have an Adafruit DC and Stepper Motor Hat that I wish to use for the steppers.

I am evaluating the purchase of the Adafruit 16-channel PWM/Servo Hat and Bonnet to use for servos.

I believe I can use there 2 hats together because they are both I2C hats. I will need to use the address jumpers to use both boards on the same Pi.

Does anyone have experience with this? Reviews? Concerns?

  • A HAT seems overkill to drive a couple of servos. I suppose it might make the wiring simpler. Even so I'd just use the Pi to send the servo pulses.
    – joan
    Oct 30 '19 at 18:24
  • I thought of that too. However, in addition to running servos, the hat can provide additional PWM functionality. When it comes to adding a bunch of blinking/dimming LEDs, this will come in handy. Oct 30 '19 at 18:39
  • Possibly. However all devices connected to that HAT have to use the same frequency. The servos need 50 Hz so your LEDs will have to be driven at 50 Hz also.
    – joan
    Oct 30 '19 at 18:48
  • This is a consideration, for sure. Oct 30 '19 at 19:05
  • It looks like they use different I2C addresses by default (0x60 and 0x40) so you should be good to go using both. Using HATs like this to offload the real-time PWM and servo control is a perfectly good idea and can really simplify your life in coding and debugging unexpected issues. The only thing to watch out for becomes the bandwidth limitations of I2C itself if you want to update the motors too frequently.
    – Fred
    Nov 2 '19 at 9:13

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