/* * HID RFID Reader Wiegand Interface for Arduino Uno * Written by Daniel Smith, 2012.01.30 * www.pagemac.com * * This program will decode the wiegand data from a HID RFID Reader (or, theoretically, * any other device that outputs weigand data). * The Wiegand interface has two data lines, DATA0 and DATA1. These lines are normall held * high at 5V. When a 0 is sent, DATA0 drops to 0V for a few us. When a 1 is sent, DATA1 drops * to 0V for a few us. There is usually a few ms between the pulses. * * Your reader should have at least 4 connections (some readers have more). Connect the Red wire * to 5V. Connect the black to ground. Connect the green wire (DATA0) to Digital Pin 2 (INT0). * Connect the white wire (DATA1) to Digital Pin 3 (INT1). That's it! * * Operation is simple - each of the data lines are connected to hardware interrupt lines. When * one drops low, an interrupt routine is called and some bits are flipped. After some time of * of not receiving any bits, the Arduino will decode the data. I've only added the 26 bit and * 35 bit formats, but you can easily add more. */ #define MAX_BITS 100 // max number of bits #define WEIGAND_WAIT_TIME 3000 // time to wait for another weigand pulse. unsigned char databits[MAX_BITS]; // stores all of the data bits unsigned char bitCount; // number of bits currently captured unsigned char flagDone; // goes low when data is currently being captured unsigned int weigand_counter; // countdown until we assume there are no more bits unsigned long facilityCode=0; // decoded facility code unsigned long cardCode=0; // decoded card code // interrupt that happens when INTO goes low (0 bit) void ISR_INT0() { //Serial.print("0"); // uncomment this line to display raw binary bitCount++; flagDone = 0; weigand_counter = WEIGAND_WAIT_TIME; } // interrupt that happens when INT1 goes low (1 bit) void ISR_INT1() { //Serial.print("1"); // uncomment this line to display raw binary databits[bitCount] = 1; bitCount++; flagDone = 0; weigand_counter = WEIGAND_WAIT_TIME; } void setup() { pinMode(13, OUTPUT); // LED pinMode(2, INPUT); // DATA0 (INT0) pinMode(3, INPUT); // DATA1 (INT1) Serial.begin(9600); Serial.println("RFID Readers"); // binds the ISR functions to the falling edge of INTO and INT1 attachInterrupt(0, ISR_INT0, FALLING); attachInterrupt(1, ISR_INT1, FALLING); weigand_counter = WEIGAND_WAIT_TIME; } void loop() { // This waits to make sure that there have been no more data pulses before processing data if (!flagDone) { if (--weigand_counter == 0) flagDone = 1; } // if we have bits and we the weigand counter went out if (bitCount > 0 && flagDone) { unsigned char i; Serial.print("Read "); Serial.print(bitCount); Serial.print(" bits. "); // we will decode the bits differently depending on how many bits we have // see www.pagemac.com/azure/data_formats.php for mor info if (bitCount == 35) { // 35 bit HID Corporate 1000 format // facility code = bits 2 to 14 for (i=2; i<14; i++) { facilityCode <<=1; facilityCode |= databits[i]; } // card code = bits 15 to 34 for (i=14; i<34; i++) { cardCode <<=1; cardCode |= databits[i]; } printBits(); } else if (bitCount == 26) { // standard 26 bit format // facility code = bits 2 to 9 for (i=1; i<9; i++) { facilityCode <<=1; facilityCode |= databits[i]; } // card code = bits 10 to 23 for (i=9; i<25; i++) { cardCode <<=1; cardCode |= databits[i]; } printBits(); } else { // you can add other formats if you want! Serial.println("Unable to decode."); } // cleanup and get ready for the next card bitCount = 0; facilityCode = 0; cardCode = 0; for (i=0; i