Charliewatch

An "Analog" watch with 72 (60+12) Charlieplexed LEDs. Based on Travis Goodspeed's GoodWatch21 schematic, using the CC430F5137IRGZR CPU, which doesn't have the LCD controller of the CC430F6xxx in the GoodWatch.

v0.2 works, although it has no radio parts. It is exactly 1 square inch of PCB and should fit in a 38mm or 36mm case.

See it in action: https://www.youtube.com/watch?v=VaebR-6KNXE

Charliewtch schematic

Bill Of Materials (BOM)

• CC430F5137IRGZR https://www.mouser.co.uk/ProductDetail/595-CC430F5137IRGZR

• 0603 68k Resistor ERA3AEB683V

• 0603 Red LED KP-1608EC

• KEYSTONE 3002 Battery Contact, Coin Cell - 20mm, SMD 3002

• IQD FREQUENCY PRODUCTS LFXTAL050789 Crystal, 32.768 kHz, SMD, 2mm x 1.2mm, 12.5 pF, 20 ppm, IQXC-25 Series LFXTAL050789

• Push button - Omron B3U3100P

Programming

Programmed via TI Code Composer Studio using the Programmer/Debugger on the MSP430 FR4133 Launchpad. http://www.ti.com/tool/MSP-EXP430FR4133

Programming cable

From the top of the board: (Wiring from watch to Programmer/Debugger on MSP430 FR4133 Launchpad)

• TST - SBWTCK
• RST - SBWTDIO
• RX - RXD
• TX - TXD
• VCC - 3V3
• GND - GND

There is also a four-wire setup that might simplify the wiring. Travis documents it and the power consumption here: https://github.com/travisgoodspeed/goodwatch/wiki/EnergyTrace

Bricked Launchpad

If you brick your launchpad by running Energia under Linux, it will no longer program the Charliewatch. The other weirdness is that tilib can detect the device, but can't write to it unless run as root.

Energy Trace

• libmsp430.so: https://dlbeer.co.nz/articles/slac460y/index.html
• https://github.com/carrotIndustries/energytrace-util
• Have to update path to MSP430.h from the slac/DLL430_v3/include directory