nodemcu-firmware/docs/modules/wiegand.md

wiegand Module

Since	Origin / Contributor	Maintainer	Source
2020-07-08	Cody Cutrer	Cody Cutrer	wiegand.c

This module can read the input from RFID/keypad readers that support Wiegand outputs. 4 (keypress) and 26 (Wiegand standard) bit formats are supported. Wiegand requires three connections - two GPIOs connected to D0 and D1 datalines, and a ground connection.

wiegand.create()

Creates a dynamic wiegand object that receives a callback when data is received. Initialize the nodemcu to talk to a Wiegand keypad

Syntax

wiegand.create(pinD0, pinD1, callback)

Parameters

• pinD0 This is a GPIO number (excluding 0) and connects to the D0 data line
• pinD1 This is a GPIO number (excluding 0) and connects to the D1 data line
• callback This is a function that will invoked when a full card or keypress is read.

The callback will be invoked with two arguments when a card is received. The first argument is the received code, the second is the number of bits in the format (4, 26). For 4-bit format, it's just an integer of the key they pressed; * is 10, and # is 11. For 26-bit format, it's the raw code. If you want to separate it into site codes and card numbers, you'll need to do the arithmetic yourself (top 8 bits are site code; bottom 16 are card numbers).

Returns

wiegand object. If the arguments are in error, or the operation cannot be completed, then an error is thrown.

Example

local w = wiegand.create(1, 2, function (card, bits)
  print("Card=" .. card .. " bits=" .. bits)
end)
w:close()

Wiegand Object Methods

wiegandobj:close()

Releases the resources associated with the card reader.

Syntax

wiegandobj:close()

Example

wiegandobj:close()