@Moon wow i never heard of those! That is a neat idea tho. The button feeds and and connects the processor in the ring to the 1 wire pin of the arduino .. right?
I really need to undust mine. I was using it with a sim800l module to process sms as commands for a gate but i stopped at some point
When I touch the ring, the probe provides power to the ring which contains a microprocessor that communicates over 1Wire. the bus master side (arduino) does a search command over the network and the ring replies back with a family id (what model of iButton) and a 48-bit unique ID, and a CRC to check that they're intact.
When I get the response, I parse the ID and compare it to the ID I have stored as belonging only to my key, and then play a tone and led pattern depending on if it matches or not.