The Use Of Wiegand

[espruino-discuss]

Posted at 2017-09-26 by Alexander

I want to hook the reader Matrix3 want to use the Wiegand Protocol. Is this possible? If to how? Maybe someone has done this before and have an example? Since iButton DS1990A on 1wire is bad.

[espruino-discuss]

Posted at 2017-09-26 by @allObjects

...a pretty weird protocol... Wiegand Interface Definition and Micro RWD EM4001 “Mag swipe” Decimal Output Version.

Is that what you are talking about?

Seems to be a 500bps protocol... a state-machine in Espruino could implement it with setWatch()'s on two RX connected to the sensor's/reader's TX (and of course two more connections for the communication in the other direction).

I'm though not sure that ESP8266 has the capacity and the option to serve that state machine, because of the Wifi demands (interrupt requests) which come first (are of higher priority and are served first). - I read somewhere that you have about 15ms for a piece of event driven JavaScript to execute... if it takes longer, something gives way and the whole falls apart.