Lab_interaccio/2009/RFID2/applet/RFID2.cpp

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2025-02-25 21:21:58 +01:00
// RFID reader ID-12 for Arduino
// Based on code by BARRAGAN <http://people.interaction-ivrea.it/h.barragan>
// and code from HC Gilje - http://hcgilje.wordpress.com/resources/rfid_id12_tagreader/
// Modified for Arudino by djmatic
// Modified for ID-12 and checksum by Martijn The - http://www.martijnthe.nl/
//
// Use the drawings from HC Gilje to wire up the ID-12.
// Remark: disconnect the rx serial wire to the ID-12 when uploading the sketch
#include "WProgram.h"
void setup();
void loop ();
void setup() {
Serial.begin(9600); // connect to the serial port
}
void loop () {
byte i = 0;
byte val = 0;
byte code[6];
byte checksum = 0;
byte bytesread = 0;
byte tempbyte = 0;
if(Serial.available() > 0) {
if((val = Serial.read()) == 2) { // check for header
bytesread = 0;
while (bytesread < 12) { // read 10 digit code + 2 digit checksum
if( Serial.available() > 0) {
val = Serial.read();
if((val == 0x0D)||(val == 0x0A)||(val == 0x03)||(val == 0x02)) { // if header or stop bytes before the 10 digit reading
break; // stop reading
}
// Do Ascii/Hex conversion:
if ((val >= '0') && (val <= '9')) {
val = val - '0';
} else if ((val >= 'A') && (val <= 'F')) {
val = 10 + val - 'A';
}
// Every two hex-digits, add byte to code:
if (bytesread & 1 == 1) {
// make some space for this hex-digit by
// shifting the previous hex-digit with 4 bits to the left:
code[bytesread >> 1] = (val | (tempbyte << 4));
if (bytesread >> 1 != 5) { // If we're at the checksum byte,
checksum ^= code[bytesread >> 1]; // Calculate the checksum... (XOR)
};
} else {
tempbyte = val; // Store the first hex digit first...
};
bytesread++; // ready to read next digit
}
}
// Output to Serial:
if (bytesread == 12) { // if 12 digit read is complete
Serial.print("5-byte code: ");
for (i=0; i<5; i++) {
if (code[i] < 16) Serial.print("0");
Serial.print(code[i], HEX);
Serial.print(" ");
}
Serial.println();
Serial.print("Checksum: ");
Serial.print(code[5], HEX);
Serial.println(code[5] == checksum ? " -- passed." : " -- error.");
Serial.println();
}
bytesread = 0;
}
}
}
int main(void)
{
init();
setup();
for (;;)
loop();
return 0;
}