Awhile ago, Amatus and I decided we needed a way to read and program serial EEPROMs. Serial EEPROMs are in all kinds of digital consumer electronics. They are usually pretty small and only hold enough data to store things like a serial number and some metrics or user preferences. The particular EEPROM we tried first was an ST 24c02, shown below, attached to a handy PCB and connector. I built an I2C to PC-parallel adapter board and Amatus wrote a quick program to talk to the EEPROM. For a final casing, I painstakingly crafted a steel chasis, resembling an Altoids can, with the help of the following tools:
Getting the EEPROM to reveal it's golden, juicy secrets did not take long. Building the adapter and writitng the code took less than a day, in total. All the information to build the adapter and write the software are widely available. I'll post a copy of the schematic and program source when I get around to it. All parts were purchased at the local electronics hobby store for under $5. Shop smart, support your local businesses.
LS05 pin 14 (Vcc) o -------
| | |
+--+--+---------------------+--+--+------------+------+-o 1 |
| | | | | | ===.1uF | +5V |
-------- [R][R][R] 3x10K 3x10K [R][R][R] LS05 | | |
| | | | | | | | pin 7 o-+------+-o 2 |
| 12 o-+--+ | | 3|\ 4 | | | (Gnd) | GND |
| 17 o-+-----|--|----| >o-------------+--|--|--------------+ | |
| | | | |/ 8 /|9 | | 10 /|11 +----+-o 3 |
| 15 o-+-----+--|--------------o< |------+--|------o< |----+ | SCL |
| | | 1|\ 2 \| | \| | |
| 9 o-+--------|----| >o-------------------+--------------+----+-o 4 |
| | | |/ 6 /|5 | | SDA |
| 11 o-+--------+----------------------------------o< |----+ -------
| 10 o-+-+ \| 4-pin
| 13 o-+-+--oGND Connector
| 25 o-+-+ ------------------ Part List --------------------------
-------- | 1 - .1 uF capacitor | 6 - 10K 5% resistors |
25-pin male D | 1 - 4-pin connector | 1 - 25-pin male D connector |
connector to PC | 1 - 74LS05 open collector hex inverter |
printer port -------------------------------------------------------
