I designed a new breakout board for a pressure sensor today, for the MPX2053DP sensor. It took me a while to get the unibody outline drawn in an Eagle library so that I could place the part.
I could get 10 copies of the board from ITEAD for the same price as the instrumentation amp prototyping boards ($9.90 for 10, plus shipping), since they are 1.25″×1.1″, or 3.175cm×2.794cm, which is under the 5cm×5cm breakpoint for that price. I could get 3 copies from OSHPark for $6.88 (including shipping). If I later need a larger number of boards, I can get 100 boards smaller than 5cm×5cm for $75 or 200 for $120 from ITEAD, but I don’t think I’ll need that many this year, since we’ll either make a dozen pressure sensors for the lab, or have each student solder up their own (for which 30 boards would be plenty this year).
I also found a source for a cheap capacitor collection that we may be able to use for the student kits. It has 10 each of 25 different values from 1pF to 0.1µF. I would have preferred slightly larger values (say, 47pF to 4.7µF), but at $4.80 for 250 capacitors it seems like a pretty good deal. Unfortunately, I can’t tell if they are 0.1″ or 0.2″ spacing on the leads, which would make a difference for my protoboard design. If I order the pressure sensor breakout boards from ITEAD, I could order capacitors at the same time.