Here is a short video showing how everything just stops when the bypass cap from my Etch-a-Sketch to chart Temperature vs Time is removed. Connect the bypass cap and, like magic, everything is back to normal. Pretty amazing, huh?
-----If you follow DIY projects on the web you see this issue frequently. The fix often is simply to add a capacitor between power and ground. This is called a by-pass cap or decoupling cap. They are most useful in projects with electrical noise or where larger loads like motors, solenoids, relays, etc. are involved.
As I said, this recently happened to me. I had the great idea to use two stepper motors mounted to an Etch-a-Sketch to chart Temperature vs Time. The project came off fine in the end, but not without a bump in the road.
The rig was stable with one stepper motor. However, adding the second stepper motor made everything 'wacky'. Sometimes the PICAXE 18M2 microcontroller would not even accept new code downloads. All fixed with a by-pass cap.
Below is short video of the finished rig in action. (Thanks Hack-a-Day for featuring it!) Take a look at the build page if you are interested in duplicating the project.
Thanks for the visit and "All hail the mighty bypass cap"!!!