Homework was to use circuits to construct the 5 fundamental logic gates: NOT, AND, OR, NOR (Not Or), NAND (Not And). I also added the trivial Buffer case as well. Yay electricity! And logic! And physics!

Lesson learned: if nothing seems to be working, check to see if your battery is still connected or if you have to redo the soder :).

Also, why don’t breadboards make it visibly more obvious which holes are connected to each other. For reference, the sides are connected the long way which is sort of marked. But, they don’t connect through the halfway point. And, the 5-across rows are connected horizontally. This could be made more obvious with design. But, I guess you just learn it quickly and then know it forever.

Buffer

Not

And

Or

Nor

Nand

Still lingering question: the transitor seems to work forwards or backwards if there is only one (or if you have them all backwards). In oher words, if you switch the emittor and the collector. But, evidently they’re not supposed to be used backwards. I will have to do some more research to learn why this seems to work (at least with just one LED), but is not a good idea.