We would like for them to be able to integrate the art & music projects that they have created in Snap! with extensions that will enable them to incorporate kinetic art / motion.
Therefore, an extension that could control an external motor from Snap! would be better. The precise model of the microcontroller is not important as long as it is (a) affordable and (b) can be controlled by a PC or Chromebook.
We collaborated with Roger Wagner to develop a shield for the Arduino, now in its fourth iteration, that includes a motor controller.
This works well, and we have been using it with Snap4Arduino for several years. However, the combination of the Arduino plus the shield & motor controller costs about $25. So, in cases in which we would like each student in a class of 20 students to take away a working motor & controller, the cost is about $500 per class.
We haven't worked with the Raspberry Pi, but the low cost ($4) seems attractive if we had a way to communicate with it from a PC using Snap! (We could probably add an amplifier to the output to obtain enough current to drive a motor.)
If we attempted to run Snap! on a Raspberry Pi, we would need to acquire monitors, keyboards, etc., to obtain complete working systems usable as stand-alone computers. Since the students already have PCs and Chromebooks, this would quickly drive up the cost. It seems as though it would be more economical to connect a Raspberry Pico to a PC and use it as a microcontroller. Is there something that we're missing or not understanding about the economics?
When we have some time later this summer, we may acquire a Raspberry Pico to gain some firsthand experience and get a better idea of its potential. The price and size are certainly attractive. Thanks for the suggestions.
"Serial port" library allows direct access to any USB/CDC (serial port emulation) device. So you can "talk" to a program running on the microcontroller board.
With micropython@Pico in REPL mode, everything you send to the board is interpreted as a program.
There is a typical led switching program (not tested yet as my pico is buried somewhere)
There are cheap lightweight servos known as the SG90/MG90, easily modifiable to continuous rotation and driven directly by single I/O line.
Those are available through global retailers or EB for less than 2$ each.