Adding Bluetooth to digital calipers
Modified calipers with bluetooth addition
Federico Conci might just win the "husband of the year" award with this bit of practical engineering. His wife has a job that requires measuring fruits, leaves, and stems with digital calipers. This measurement takes place in the canopy of a tree, so you can only imagine what a horrible nightmare a pair of wired calipers would be.
Federico stepped up to resolve this issue by modifying some digital calipers to have Bluetooth capabilities. This way his wife can record her measurements without becoming tangled in the treetops!
The additional circuit
Not only did Federico construct a custom circuit based around a PIC12F629 to read the caliper and transmit the data through a Bluetooth module, he even constructed his own flex cables from scratch! We see PCBs created all the time, but a homemade flex cable? That is truly inspiring. To make his flex cable, he glued brass sheeting to overhead transparency material with the correct symbols printed on it.
Amazingly well done home made flex cable.
You can find more details, including code and schematics on his website.