Ok, got it, along with the other points about resistance and signal/power. Thanks.
That makes sense. I'm assuming the power draw of LEDs (and small speakers?) is low enough to be an exception - is that right?
It is a Mimic, and you saw that before I did!
I had no idea! Sounds like I should keep an eye out for a simple project using external power for a motor while using an Arduino for control. I'll see what I can find.
For any other beginners coming here, here's the condensed version of what I learned from this thread and this project:
- User-made Libraries can have compatibility problems with other Libraries. See Posts 10 and 34.
- Documentation for user Libraries isn't in the 'Read Me' file but rather in the '.h' file, which can give info about the various definitions used. See Posts 4 and 16.
- Be careful following old Arduino projects as models. Newer ones can contain errors, too, but some old code is now obviated. See Posts 21, 24, and 34.
- Other people's Arduino projects can contain errors not just in the code, but even in the circuitry. I figured anyone who drew a schematic or a Tinkercard diagram must know what they're doing, but that's not necessarily so.
- Writing your own instructions in C++ is fun and not nearly as hard as I feared.
- You can go through all the Tutorials in the Arduino Starter Kit and still have a lot to learn about even basic projects. It's a big open-source world out there.