iButton is useful for authentication (antitheft).
Similar to a battery-holder (with 2 metal contacts) that iButton can be easily touched against.
Separate lamp or LED cathode can be connected to VEMS ECU low power ("p259") output (configured as Output / Warning light, also called CEL/Check Engine Light) so that it flashes until touchon of correct button.
- I-button reader case must be connected to GND (signal-GND)
- I-button middle pin must be connected to EC18/pin16
The smarties are inside the related products, at least 1 needed from each to be useful:
- 2 iButtons can be useful: 2nd ibutton switches to eeprom page-B. Example usage: page-A can be "wallet-mode" and page-B can be high power (or "fallback to safe-defaults" and "cutting-edge under-tuning", whatever one likes)
- DS2480B interface chip
- VEMS ECU
- 10mm LED