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Personal fingerprint recognition doorbell Answered

Anybody fancy making a fingerprint-reading doorbell, that gives out different rings/does different things depending on who it is? Maybe even with an option to ignore anybody whose print is not registered for the days when one is too murderous to deal with the general public?

From scratch(ish), would be a waste to destroy an expensive security system just for this (maybe).


As CrapFlinger pointed out, building a fingerprint ID truly "from scratch" is an extreme technological challenge. 

Your best bet would probably be to buy one of the cheap USB scanners on the market (Google says under $40!), and do up either a custom "micro notebook" board to handle the software and launching a doorbell chime program, or just hook it up to an old/used/low-end laptop in a drawer near the door. 

This would be mostly a software project, obviously, but still worth an I'ble if you get it going!

from scratch would be difficult....a lot goes into fingerprint reading...especially accurate fingerprint reading.

you've got to have just the right IR spectrum to get a reading through crud on peoples fingers (the best readers actually read the fingerprint from the 2nd layer of skin not the first). then it's got to be able to translate what it sees into some form of mathematical algorithm (most commercial readers pick anywhere between 5 and 100 individual points in the print depending on how secure they are) then it's got to have some form of database to check the algoritym against to preform an action otherwise anyone could get in (either internally or external)

it would be slightly easier to just "hack" an existing system