Suggestions for controlling motors?

[sgbaird]

How would you recommend driving a motor using the Maker Pi Pico base? I'm interested in controlling this peristaltic pump. Or is there something other than the Maker Pi Pico base that you'd recommend? For me, I want it to be WiFi-enabled, so preferably something that works with the Pico W.

CytronTechnologies/MAKER-PI-RP2040#4

EDIT: Perhaps https://shop.pimoroni.com/products/automation-2040-w

[kiate]

If Pico W is your preferred choice, you may consider to use Maker Drive for motor control. This little motor driver not only allows you to control the motor speed, it has a 5V output which can be used to power up the Pico W via the VSYS pin too. You may even skip Maker Pi Pico Base if the expansion and onboard features are not needed. However, it would come in handy for creating projects. The MicroPython library for motor control is available here

[kiate]

@sgbaird I got super excited with the Pico W... quickly connect a few things together and it works! All thanks to wonderful getting started guide by Raspberry Pi.
You may take a look at my proof-of-concept here.

[sgbaird]

@kiate thanks for the link to the Maker Drive and your example code! I think this will help a lot. Agreed about the nice getting started guide, and the Pico W has also been exciting to me 😁. For provenance, I came across a few more options:

• Maker Drive (which you mentioned, but seems to be out-of-stock, 2022-09-08, but available in some of the other distributors in limited quantities). 9.5 V max
• Motor Driver Board for Raspberry Pi Pico. 10V max
• Robotics Board for Raspberry Pi Pico 10.8V max
• DC Motor Driver Module for Raspberry Pi Pico, 6-12V input, benefit of having a breakout for all the pins
• Grove - I2C Motor Driver with L298 (out-of-stock, 2022-09-08)
• Grove - I2C Motor Driver (TB6612FNG) (out-of-stock, 2022-09-08)
• Grove - MOSFET for Arduino (might require a logic leveler to deal with 3.3V on Pico W vs. assumed minimum of 5V). 5-15V. Hmm.. maybe this works ok with 3.3V logic? (see here and this SeeedStudio forum post EDIT: seems to be compatible with Raspberry Pi - there's a tutorial of using it with an RPi)
• Maker MDD3A. Essentially the Maker Drive, but a bit more expensive and tolerant of 4-16V (and higher currents)
• Grove Screw Terminal which might be useful for using a board that doesn't have a Grove port by default
• Grove to Jumper cables (might be useful with the Maker Drive)
• https://www.amazon.com/Qunqi-Controller-Module-Stepper-Arduino/dp/B014KMHSW6
• Stemma-QT/Grove logic-level shifter (having trouble finding a grove-to-grove logic level shifter)
• Grove relay (just ON/OFF)
• RC speed controller, idea suggested at How many can the Pico (W) run in total? KitronikLtd/Kitronik-Pico-Robotics-Board-MicroPython#6, the idea being to control DC motor power via a servo (0 = 0% power, 180 = 100% power), meaning you can also leverage the servo channels of the kitronik robotics board for Pico W. As an aside, from both a hardware and software perspective, it's probably best to keep the control to a single type to keep it modular and therefore easy to add new channels per user needs (up to the maximum of course).

Powering the Pico W via VSYS seems like a nice option! And probably OK to have both VSYS and USB connected when needing to upload code to the Pico W. I.e. do whatever code stuff needs to happen via USB, then unplug and let it run via main.py.

I've been developing MicroPython code for the Pico W here.

[kiate]

Oh It's a shame that the item is not available in stock. Btw getting from distributors might be a good idea due to shipping cost and taxes.
Great info of all the parts listed there. Kitronik's board has a small form factor and is flexible for wiring with its terminal block.
Do you mind sharing what kind of project are you working on?

[sgbaird]

Oh It's a shame that the item is not available in stock. Btw getting from distributors might be a good idea due to shipping cost and taxes.

Yeah, I'll probably go with a distributor.

Great info of all the parts listed there. Kitronik's board has a small form factor and is flexible for wiring with its terminal block.

Thanks! Agreed that the Kitroniks board seems nice, though it might be nice if it had a second row of headers on each side to make arbitrary pins more easily accessible (similar to the Maker Pi Pico).

Do you mind sharing what kind of project are you working on?

Sure! The motivation for my project is nicely captured at https://acceleration.utoronto.ca/vision and was largely in response to a call for white papers. A recent manuscript version is available here. In a nutshell, it's a demo that helps teach "Industry 4.0" style principles of automation hardware and machine learning focused on laboratory-scale research settings and materials discovery. [hackaday], [github], [youtube]

[kiate]

That's a really unique use case for a product. Even a very simple feature as a built-in RGB LED can be utilized for machine learning research.

[sgbaird]

That's a really unique use case for a product. Even a very simple feature as a built-in RGB LED can be utilized for machine learning research.

Thanks! :)

[sgbaird]

As a side note, one observation is that cheaper peristaltic pumps are generally 12 V devices; however, the Maker Drive (and several others) only support output voltages up to ~10V. I can go with a 5 V peristaltic pump, but it's over 2x the cost of some of the cheaper ones. Any thoughts here?

EDIT: perhaps just using the max input voltage and driving the DC motors at the lower voltage with the Maker drive is fine.

• Liquid based color matching demo sparks-baird/self-driving-lab-demo#89

[sgbaird]

Essentially the Maker Drive, but tolerant of higher currents (3A) and voltages (4-16V): https://www.cytron.io/p-3amp-4v-16v-dc-motor-driver-2-channels

[kiate]

Hi, we've just launched a robot controller board, and it works with Raspberry Pico and Pico W
https://www.cytron.io/p-robo-pico-simplifying-robotics-with-raspberry-pi-pico

[sgbaird]

@kiate fantastic! This looks so good. Thank you for pinging me on this. I used two MDD3A's for https://github.com/sparks-baird/self-driving-lab-demo#clslabliquid. I will keep this one in mind!