Well everything's just upside down now!

I was all set to save money on PIC's by using 555 timers for the majority of my thesis circuits. (previous entry)

Background: Pic's are programmable microchips, they cost $8 and have cpu's, ram, rom I/o pins. You’ve seen other PDIP style packages (black rectangle shapes) around..(first picture). PIC’s generally use Oscillators to acquire their timing and clock cycles (second picture).

So what’s new?

The custom 555 circuit I mentioned last entry was gonna total $4 after capacitors etc which was half cost of my 16f84a chips, but yesterday I was reading about PIC’s for most of the day, and found the 16F628 !!! Rob mentioned it but hadn’t really gone into learning it yet. So I did.

Wowies!
It’s about $5 ($3 less than the 16F84a) and it has DOUBLE the code space 2k instead of 1k, as well as other features, but the kicker is it has a built in OSCILLATOR! That’s the clock that tells the chip how fast to run and what to do, it’s like the chips pulse. The clocks aren’t a big deal, but it eats up 2 pins as well as costing an extra $1 (multiply by 18 for thesis)

So do I build a multi-piece circuit with difficult to design timings with 555's and hardware programming just to save $1?

BUT WAIT! There’s more! If you order now, we'll throw the PIC in for FREE! Operators are standing by!

Yes, Microchip.com is sending me FREE samples! About $50 worth! So the cost of using a PIC is… 5cents for the socket!
So do I wrestle with capacitors and resistors to get the right delay? Or do I simply program "pause 8000" for my 8 second delay I want… hmmm tough choice.

What else did I do? Well I played with my motor shipment yesterday of course! It’s what I need that circuit to control.
And my Gear motors are AMAZING! Everything I could have EVER hoped for!!
Not only are they geared, but they have a built in circuit. When you send them a short + signal, they spin 1 full rotation exactly and then stop! And they do it in about 1-2 seconds (slow and nice) (in comparison to a normal motor that simply spins insanely fast non stop).

These will be the basis for the chest breathing mechanism of the animatronics in each.