Hi all,
I am using a PN532 RFID reader module.
In its example library is a Mifare UID reading sketch.
It outputs a reverse HEX value on the serial monitor like so; 0xCE 0x67 0x6E 0x5A
So, to get the correct UID you need to reverse this value (5A6E67CE) and then I have been using online converters etc to get the value I want (1517184974)
Ideally I would like the serial monitor to just spit out this value rather than the reverse code, I know (I'm fairly sure) it can be done in code but unfortunately don't have the ability (I'm really bad at maths), so was hoping somebody could come to my rescue...
I don't think the modification would necessarily be too complicated if you know what you are doing, although I'm not qualified to make that assertion.
Thank you for reading and any advice you may have to offer...
Here is the original code for reference;
/**************************************************************************/
/*!
This example will attempt to connect to an ISO14443A
card or tag and retrieve some basic information about it
that can be used to determine what type of card it is.
Note that you need the baud rate to be 115200 because we need to print
out the data and read from the card at the same time!
*/
/**************************************************************************/
// choose to SPI or I2C or HSU
#if 0
#include <SPI.h>
#include <PN532_SPI.h>
#include "PN532.h"
PN532_SPI pn532spi(SPI, 10);
PN532 nfc(pn532spi);
#elif 0
#include <PN532_HSU.h>
#include <PN532.h>
PN532_HSU pn532hsu(Serial1);
PN532 nfc(pn532hsu);
#else
#include <Wire.h>
#include <PN532_I2C.h>
#include <PN532.h>
PN532_I2C pn532i2c(Wire);
PN532 nfc(pn532i2c);
#endif
void setup(void) {
Serial.begin(115200);
Serial.println("Hello!");
nfc.begin();
uint32_t versiondata = nfc.getFirmwareVersion();
if (! versiondata) {
Serial.print("Didn't find PN53x board");
while (1); // halt
}
// Got ok data, print it out!
Serial.print("Found chip PN5"); Serial.println((versiondata>>24) & 0xFF, HEX);
Serial.print("Firmware ver. "); Serial.print((versiondata>>16) & 0xFF, DEC);
Serial.print('.'); Serial.println((versiondata>>8) & 0xFF, DEC);
// Set the max number of retry attempts to read from a card
// This prevents us from waiting forever for a card, which is
// the default behaviour of the PN532.
nfc.setPassiveActivationRetries(0xFF);
// configure board to read RFID tags
nfc.SAMConfig();
Serial.println("Waiting for an ISO14443A card");
}
void loop(void) {
boolean success;
uint8_t uid[] = { 0, 0, 0, 0, 0, 0, 0 }; // Buffer to store the returned UID
uint8_t uidLength; // Length of the UID (4 or 7 bytes depending on ISO14443A card type)
// Wait for an ISO14443A type cards (Mifare, etc.). When one is found
// 'uid' will be populated with the UID, and uidLength will indicate
// if the uid is 4 bytes (Mifare Classic) or 7 bytes (Mifare Ultralight)
success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, &uid[0], &uidLength);
if (success) {
Serial.println("Found a card!");
Serial.print("UID Length: ");Serial.print(uidLength, DEC);Serial.println(" bytes");
Serial.print("UID Value: ");
for (uint8_t i=0; i < uidLength; i++)
{
Serial.print(" 0x");Serial.print(uid[i], HEX);
}
Serial.println("");
// Wait 1 second before continuing
delay(1000);
}
else
{
// PN532 probably timed out waiting for a card
Serial.println("Timed out waiting for a card");
}
}