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lecture: Building a Damned Good Watch

An Adventure in Amateur Radio


This lecture describes the design and implementation of the GoodWatch, an open source calculator watch for reverse engineers and amateur radio operators. Built around a CC430 chip from Texas Instruments, it provides years of battery life and a half dozen useful tools, including a spectrum analyzer and a Morse code transmitter.

This lecture begins with Casio's 3208 watch module design, describing how the mechanical dimensions of the board and the pinouts of its connectors were reverse engineered, then bootstrapped into a new PCB with minimal drivers.

Then we'll cover the radio design, in which a 70cm transceiver can be fit into such a small case by using the metal watchband as a random wire antenna. And power management, in which firmware can be carefully written to be fast and responsive while running for years on a CR2016 coin cell battery.

Full hardware CAD and software source code for this watch are freely available, with forks and pull requests welcome. Some PCBs will be on hand for those fine folks who would like to build their own.


Day: 2018-08-25
Start time: 18:20
Duration: 00:50
Room: Klapka


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