Here’s the first permanent board for a node that is intended for the kitchen.The bell doesn’t work yet, but the rest of the circuit is there, including everyone’s favorite feature, a clock! This is a copy of the breadboard Node #2 and its program, so just receives the message from Node #1, but not the sensor reading. The RTC is provided by the DS1305 to the right of the PIC and uses the crystal hidden inside the blue shrink tube below (it was an SMD part).
Since this circuit is going up on the wall, I tried to make it look nice. The paint scheme is all the 99¢ spray variety as usual, gloss black for the piece of pine board and flat black for the perf board. To hold the LCD, I drilled undersized pockets (about the width of the flats) for the #4 nuts and stamped the hex with a rubber mallet and punch. After painting they were glued in with superglue. The circuit board and bell is similar, but are size #6 and the nuts are on the bottom.
The bell seems original to my house, but was terrible sounding when I first bought the place. I though it was wall papered over, but was just painted close to a hundred times. Once I stripped off the paint it rang instead of clattered. It rings fine from a nice beefy power supply, but sagged the puny wall wart and browns out the microcontroller. Guh, so I’ll have to get real readings and shit to get that going. Anyways, here’s what is looks like inside.
So this concludes the physical portion of the design. The MCP2551 and the ECAN engine in the PIC18F4580 takes care of that for the most part. So now I’m on to software development.