Python libraries for generating and transmitting data to the Timex Data Link series of watches using optical data tramsission. Currently only the protocol for the original Data Link (50 or 70?) is implemented.
There is a guide [written by dfries] (https://github.com/dfries/datalink_ironman/blob/github_submodules/datalink/70.txt) on the Data Link packet encoding. This information was verified using the original software, and a few errors were corrected. The data was collected using the included script timex_notebook_adapter.py, which emulates the Timex Notebook Adapter and logs all bytes sent from the program. Much easier than getting it from the CRT!
- Test everything more extensively (most tests have been comparing to data from the original Timex software) - set up unit tests
- Work on the protocol documentation
More specific work:
- Implement phone number type/letter support
- Support for date format (model 150)
- Support for multiple numbers on one phone book entry
- Add "beeps" packet
A device for sending data to the watch if you don't have access to a CRT monitor. Connected via serial port and powered by the CTS line. Initially responds to commands "x" (reply with "x", used for identification), "?" (reply with "M764\0", probably some kind of model name) and 0x55 (enter send mode, actually the first sync bytes sent). After 0x55 is received, all bytes are sent over the IR LED. To get back to the initial state, device power must be cycled. This is done by pulling CTS low for a few hundred milliseconds.
When a byte is sent to the adapter, it replies with the same byte to keep things in sync.
Since I do not have access to an actual adapter, I have no way of verifying the timings of the device. It's a safe bet, though, that they will be very similar to those from the CRT. It is also possible the data could be sent somewhat faster since it does not need to be phase locked to the CRT refresh.
Arduino code for the above protocol is available in timex_transcoder.
It works both with the Pyhton code, and with the original Timex software
using an RS232 to UART converter.
To use it you need an Arduino with ATmega328 (168 would probably work too) with 16 MHz clock. Should work with Uno, Nano, Duemilanove and others. Connect a bright LED to pin 12 (maybe with a suitable resistor in series) and that's it. Experiment with distance and intensity to get it just right. Some LEDs are very focused and offers only a narrow beam, so if you have the option, try to find a bright one with a wide beam.
What ultimately worked best for me was to use a high-intensity white LED without a resistor and shine it onto a surface. That way, the angle and position of the watch didn't matter as much.