Arduino Uno Hobby Motor possibilities

Projects General Guidance
1

Greetings forum,

I appreciate your patience in advance. Definitely in learning mode when it comes to this.

I have a project that I'm wanting to use many hobby size DC motors in, roughly 100. I'm also interested in driving as many of them as I can with an arduino set up. My question is how many of these motors (the ones available from Adafruit: DC Toy / Hobby Motor - 130 Size : ID 711 : $1.95 : Adafruit Industries, Unique & fun DIY electronics and kits) can one Arduino controller handle?

Thanks!

2

Also, is the Mega an option that would handle more motors than the Uno could?

3

What do you want the motors to do? Go in just one direction, change speed? What Kind of load?

The number of those motors which can safely be driven by an Uno is the same as for the Mega and it is 0.

Mark

4

So 0 is the number. I'm confused then because in the description on Adafruit, it says that this motor could be controlled by the motor shield or by the Arduino itself.

I would want them to be variable speed If I could manage more than one per Arduino.

5

Adafruit says:

This range makes them perfect for controlling with an Adafruit Motor Shield, or with an Arduino where you are more likely to have 5 or 9V available than a high current 3V setting.

The latter part of that sentence is incorrect. By itself, an Arduino cannot switch or control the amount of current required by that motor. However, with a transistor (with a junction transistor, also add a base resistor) for each motor, you could turn on/off or control the speed of a half-dozen or more motors per Arduino.

Edit: to elaborate a bit, with the above single-transistor configuration you can turn on and off one motor, using one digital I/O pin. With a PWM pin, you can control the speed of one motor in one direction only, from full on to full off. The number of each type of pin depends on the Arduino you choose. Last, it is possible to have one pin control a couple of transistor/motor combinations, but all the motors connected to that pin will behave similarly.

You will need a HEFTY power supply to power the motors and it should be independent of the Arduino power supply. Connect all grounds together!