RFID reader connection

Topic last updated 01 Jul 2011, by user Alan Copeland. 1 reply tag prallax, RFID, Serial
user Alan Copeland
30 Jun 2011

Hi, I'm fairly new to both MBED and programming in general. My current project is to read a rfid card and if it matches the card in the program then activate a relay, the relay code is written, where I'm having problems is with getting the mbed to correctly read the RFID tag. currently it detects the tag and prints detected rfid...| on the terminal, but never sends the tag, here is my code. Any help would be appreciated.

#include "mbed.h"

DigitalOut led(LED1); //indicates the enabled state on the board as well as the reciver
DigitalOut enable(p20); //enables the reader when 0
Serial rfid(p28, p27); //tx, rx
Serial pc(USBTX, USBRX); //For pc comunication
void * cpoin; //pointer to 'code'
char code[100]; //string to hold the alphanumeric RFID code

int main() {
cpoin = &code;
    rfid.baud(2400);//RFID reader operates at 2400 baud
    enable = 0;
    led = 0;
    while (1) {
        if (rfid.readable()) {
            rfid.scanf("%s", cpoin);
            pc.printf("detected rfid...| \n");
            pc.printf("rfid code is:", code);
            enable = 1;
            led = 1;
            wait(15);
            enable = 0;
            led = 0;
        }
    }
}

Replies

user Adam Green
01 Jul 2011

Try changing the scanf line to

rfid.scanf("%s", &code[0]);
 -- or --
rfid.scanf("%s", code);

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