Not sure what your Computer Science / Electrical Engineering background is. If this is too basic of an explanation - charge it to my head and not my heart.
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Skimming through the project - it looks like you are attempting the Option 2) Modify an USB-to-serial cable.
You're doing this because:
1) the PCLogBook requires that the dive computer be connected with a USB device (either the $$$ one sold commericially or the inexpensive one you are building.)
AND
2) you must change the characteristics of this custom built USB device by altering the VID (Vendor-ID) / PID (Product-ID) to prevent the OS from detecting it as a standard USB to Serial device. You don't have to understand what this means. Just that it is so.
The
24C02 is an EEPROM that when properly programmed and installed on your custom built USB device will make sure that the VID / PID are altered as required above.
In order to program it - you'll need to purchase / build a piece of hardware to temporarily mount the EEPROM in. This will create the electrical conditions that permit the EEPROM chip to be programmed (burned) with the EEPROM data that you have downloaded from
http://www.divecable.com/site/downloads/pl2303-24c02.zip
An example of this hardware is SI-Prog - the schematics for building it are available here:
PonyProg - Serial device programmer
You'll also need some sort of software to drive the burner hardware above - something to tell the 24C02, "Hey - this is the data that I want to program you with. Be so programmed!"
An example of the software that will drive SI-Prog is PonyProg - also described on
PonyProg - Serial device programmer.
You'll find instructions for using PonyProg with SI-Prog on the lancos site - but this project is probably starting to feel like an onion (I've got to build an EEPROM burner before I can build my dive computer interface...)
If you want to avoid building the SI-Prog yourself - you could by the EEPROM burning hardware. Googling - I found the following for about $22 (
24Cxx, 93Cxx and 25xxx Serial Eeprom programmer E-EPROM) it claims to be compatible with PonyProg - and is compatible with the 24C02 EEPROM.
Of course - I'm not vouching for this seller - use them at your own risk.
Once you have either built or bought an EEPROM burner. Use PonyProg - (or another program of your choice) to install the EEPROM data on the the 24C02 chip. Then solder the configured 24C02 chip onto the standard USB to serial device you are modifying.
If you've done everything perfectly - you'll be able to interface your dive computer to the PcLogBook Software.
If you'd like to PM me - I'd be happy to provide more direction
