Cribbage Board #10: The Wedding Board


These files are the PDF versions of the Peg and Programmer schematics. Since both the Peg and the Programmer PCBs acted as key mechanical components, pdf's of the layouts are included as well. The Peg layout was size critical (and could be made even smaller now using an ATMega8 in a MLF package).

This annotated PCB view was invaluable during construction of Pegs. In fact, this file allowed me to "outsource" construction of some of the Pegs. Rest assured, I have personally assembled >60% of the 100+ Pegs made to date. Note, because this document is an X1 revision, it has an error noted on it (the missing 0.1uF cap that proved essential for stability). This cap gets added following integration into the RCA plug

The color schematic of the Peg PCB includes the Bill Of Materials.. Simple, yes, but extremely versatile. Pegs have been embedded into numerous devices where anything larger could not have fit. Pegs can drive enough current to make things interesting, yet are simple enough to construct in a short time. Pegs are fairly low cost (the MOSFETs and LED account for >50% of the total cost). Because surface mount components are used, 30AWG wire can be attached to the solder pads quite readily. Additionally, the ISP port allows firmware upgrades. Typically, I will heatshrink an entire Peg and cut a small square port for the ISP connector.

This pdf shows the programmer board layout and some of its mechanical dimensions. Of note is the mode listing (provided for user interface) at the bottom of the board. This board utilizes the same components as the Peg, thereby keeping costs down. This board has numerous mechanical constraints, yet because of the 3D modeling it integrated without a problem.

This is the schematic of the Programmer board and includes the Bill Of Materials. Note, the input power goes through the switches before reaching the regulators. Not a big deal for people who do electronics day-in and day-out, but for a mechanical engineer, this was an insight that prevented quiescent current draw from draining the batteries. Additionally, you'll note that this circuit mimics the Peg circuit in numerous ways. This was intentionally done to reduce the number of unique parts in the Wedding Board's Bill Of Materials. This, in turn, helped keep costs down (albeit insignificantly compared to some of the high cost components).

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