Clean up and simplify code, write output as keyboard

hidReader.ino

@@ -1,64 +1,59 @@
-/*
+/* Based on:
  * HID RFID Reader Wiegand Interface for Arduino Uno
  * Originally by  Daniel Smith, 2012.01.30 -- http://www.pagemac.com/projects/rfid/arduino_wiegand
  *
  * Updated 2016-11-23 by Jon "ShakataGaNai" Davis.
  * See https://obviate.io/?p=7470 for more details & instructions
-*/
+ */
 
+#include <limits.h>
+#include <Keyboard.h>
+
+// LED pins
+#define LED_GREEN 11;
+#define LED_RED 12;
+#define BEEP_BEEP 10;
 
-#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
+#define DATA_SIZE 32
+volatile uint32_t dataBits = 0;         // stores all of the data bits
+volatile size_t bitCount = 0;           // number of bits recieved
 
-unsigned long facilityCode=0;        // decoded facility code
-unsigned long cardCode=0;            // decoded card code
+volatile unsigned char flagDone;        // goes low when data is currently being captured
+volatile unsigned int  weigand_counter; // countdown until we assume there are no more bits
 
-int LED_GREEN = 11;
-int LED_RED = 12;
-int BEEP_BEEP = 10;
-
-// interrupt that happens when INTO goes low (0 bit)
-void ISR_INT0() {
-  //Serial.print("0");   // uncomment this line to display raw binary
+inline void gotBit() {
   bitCount++;
   flagDone = 0;
   weigand_counter = WEIGAND_WAIT_TIME;
+}
 
+// interrupt that happens when INTO goes low (0 bit)
+void ISR_INT0() {
+  //Serial.print("0");
+  dataBits &= ~(1UL << (DATA_SIZE - bitCount));
+  gotBit();
 }
 
 // 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;  
+  //Serial.print("1");
+  dataBits |= 1UL << (DATA_SIZE - bitCount);
+  gotBit();
 }
 
 void setup() {
-  pinMode(LED_RED, OUTPUT);  
-  pinMode(LED_GREEN, OUTPUT);  
-  pinMode(BEEP_BEEP, OUTPUT);  
-  digitalWrite(LED_RED, HIGH); // High = Off
-  digitalWrite(BEEP_BEEP, HIGH); // High = off
-  digitalWrite(LED_GREEN, LOW);  // Low = On
   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;
+  Keyboard.begin();
 }
 
 void loop()
@@ -72,82 +67,39 @@ void loop()
   // if we have bits and we the weigand counter went out
   if (bitCount > 0 && flagDone) {
     unsigned char i;
+    uint32_t data = dataBits >> (DATA_SIZE - bitCount + 1);
 
     Serial.print("Read ");
     Serial.print(bitCount);
-    Serial.print(" bits. ");
+    Serial.print(" bits: ");
+    Serial.println(data, BIN);
 
-    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];
-      }
+    // standard 26 bit format:
+    // P: parity bit, F: facility code, C: card code
+    // PFFFFFFFFCCCCCCCCCCCCCCCCP
+    if (bitCount == 26) {
+      uint8_t facilityCode = (data >> 17);
+      uint16_t cardCode = (data >> 1);
+      // TODO: check parity bits
 
-      // 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();  
+      Keyboard.print(facilityCode);
+      Keyboard.print('\t');
+      Keyboard.print(cardCode);
+      Keyboard.print('\n');
+      printBits(facilityCode, cardCode);
     }
     else {
-     // you can add other formats if you want!
-     // Serial.println("Unable to decode."); 
+      // TODO: handle failures and other formats
     }
 
-     // cleanup and get ready for the next card
+    // reset for the next card
     bitCount = 0;
-     facilityCode = 0;
-     cardCode = 0;
-     for (i=0; i<MAX_BITS; i++) 
-     {
-       databits[i] = 0;
-     }
   }
 }
 
-void printBits() {
+void printBits(uint8_t facilityCode, uint16_t cardCode) {
   Serial.print("FC = ");
   Serial.print(facilityCode);
   Serial.print(", CC = ");
   Serial.println(cardCode);
-
-      // Now lets play with some LED's for fun:
-      digitalWrite(LED_RED, LOW); // Red
-      if(cardCode == 12345){
-        // If this one "bad" card, turn off green
-        // so it's just red. Otherwise you get orange-ish
-        digitalWrite(LED_GREEN, HIGH); 
-      }
-      delay(500);
-      digitalWrite(LED_RED, HIGH);  // Red Off
-      digitalWrite(LED_GREEN, LOW);  // Green back on
- 
-      // Lets be annoying and beep more
-      digitalWrite(BEEP_BEEP, LOW);
-      delay(500);
-      digitalWrite(BEEP_BEEP, HIGH);
-      delay(500);
-      digitalWrite(BEEP_BEEP, LOW);
-      delay(500);
-      digitalWrite(BEEP_BEEP, HIGH);
 }