Hi,
I'm having loads of small problems and also loads of small successes with this newbie project I'm trying to do.
My plan is to use two shift registers to eventually drive relays to hit things to make chords. (12 things, 12 tones=every possible chord.) As an intermediate step, I'm just turning on and off a bunch of LEDs connected to the shift reg. Once those are working properly, I'll switch to relays.
The most frustrating thing right now: My shift register will turn off randomly from time to time. I can make it work again by unplugging the Vcc 5V, but then it quits sooner and sooner until I give it a rest. Plugging in the 5V somewhere else on the rail seems to help. The chip's cool to the touch, so no overheating, but maybe there's some capacitance weirdness happening somewhere?
I'm new to this and don't know enough about circuits to do this by the book, but I put in a bunch of tiny tiny capacitors .1uF and that seems to have helped some. I still get all sorts of weird behavior, though, the pinnacle of which is: If I pick up the breadboard in my hands, the shift register comes on and the LEDs start working. (I'm running count-to-255 code now, and it starts wherever the Arduino is in the sequence... so the Arduino seems to be fine.) Then, after I set it down, it works for 7-10 seconds more, and then quits.
Could this be some weird capacitance thing? My body acting as a decoupler?
I'll work on a diagram. But this seems like the kind of thing that one of the "God Members" could read and just say "Oh yes, grasshopper. You're forgetting ______."
Perhaps?
Thanks,
Charlie