Electronic – How to build a circuit in a breadboard?

Given the lack of actual measurements thus far, I've decided to upload some measurements of my own. I used a ruler and a magnifier because I don't have anything more accurate, but I verified the measurements by pulling some pins out of a .1" header and test fitting it in the measurements indicated.

| BB  | A  | B  | C  | D  | E  | 1  | 2  | 3  | 4  | R4 |
|-----|----|----|----|----|----|----|----|----|----|----|
| Top | .3-| .1 | .4 | .3 | .3 | .2-| .4 | .2 | .2 | 0  |
| 2nd | NA | .1 | .4 | .3 | .3 | .2 | .4 | .2 | .3 | inf|
| 3rd | .2+| .15| .4 | .3 | .3 | .2 | .4 | .2 | .3 | inf|
| Bot | .3-| .1 | .4 | .3 | .3 | .2-| .4 | .2 | .2 | 0  |

A measurement like .3- means that it was slightly smaller than .3, but not .25 or .3. Measurement 4 is the distance between the center two power rails (notice that it's different on the middle 2), and R4 is the resistance between the top and bottom of the measurement.

The breadboards I used are shown in the following picture, numbered 1 (on the bottom) to 4.

The one on top of the stack is from RSR, the next is a couple old 3M Super Strips. I think that the third might be a Twin Industries model, but I don't know that. It and the bottom one were purchased by my school and the guys who would know where they're from don't get back until Monday.

I'd love to have some Twin Industries, Parallax, Global Specialties, Sparkfun, Seeedstudio, and Adafruit measurements. I'm about ready to just email all of those manufacturers and ask them to take some calipers out to the warehouse, but I feel bad asking for that kind of a favor without intending to buy one of them.

Fortunately, if you're using the internal clock, that 168MHz doesn't ever get to the breadboard. Think of your max frequency as what's going on at the pins.

For that processor, though, the simplest way to go is to pick up the stm32f4 discovery board for about $15, and do your prototyping with that. The useful pins are all broken out for you.

To get the signals you need from the Discovery board to something you can get at more is easy. I like using 50-pin ribbon cable breakouts. I use them to bring signals to breadboards, but they'll also bring them to solderable things like vectorboards. The ribbon cable, of course, attaches directly to the Discovery board headers.

This is all intermediate steps, of course. Eventually, when the bits and pieces of the design are all finished, you can print up a PCB with confidence, and move everything there. If I may offer advice, though, a 100 pin package with 0.5mm pitch isn't necessarily the friendliest way to break into surface mounted devices.