Parallax 28440 interfaced with Arduino mega 2560

Projects General Guidance
1

I recently bought a parallax rfid reader model 28440. I am trying to interface it with an Arduino Mega 2560. The light turns red but it is not reading any of the rfid tags i bought. My current code follows .

#include <SoftwareSerial.h>
#define RFID_READ 0x01
#define txPin 18
#define rxPin 24

SoftwareSerial mySerial(rxPin, txPin);
int val;
int runs = 0;

void setup()
{
Serial.begin(9600);
Serial.println("RFID Read/Write Test");
mySerial.begin(9600);
pinMode(txPin, OUTPUT);
pinMode(rxPin, INPUT);
}

void suppressAll() //suppresses the "null result" from being printed if no RFID tag is present
{
if(mySerial.available() > 0)
{ mySerial.read();
suppressAll();
}
}

void loop()
{
int val;
mySerial.print("!RW");
mySerial.write(byte(RFID_READ));
mySerial.write(byte(32));

if(mySerial.available() > 0)
{
val = mySerial.read(); //The mySerial.read() procedure is called, but the result is not printed because I don't want the "error message: 1" cluttering up the serial monitor
if (val != 1) //If the error code is anything other than 1, then the RFID tag was not read correctly and any data collected is meaningless. In this case since we don't care about the resultant values they can be suppressed
{suppressAll();}
}

if(mySerial.available() > 0) {
val = mySerial.read();
Serial.print("1st:");
Serial.println(val, HEX);
}

if(mySerial.available() > 0) {
val = mySerial.read();
Serial.print("2nd:");
Serial.println(val, HEX);
}

if(mySerial.available() > 0) {
val = mySerial.read();
Serial.print("3rd:");
Serial.println(val, HEX);
}

if(mySerial.available() > 0) {
val = mySerial.read();
Serial.print("4th:");
Serial.println(val, HEX);
Serial.println("-----------------");
}

delay(750);
}

I have read about 2 dozed forems and I am lost trying to get this to work. Any hlp would be appreciated. Thanks in advance.

2

A week or so ago, somebody was trying to work out his RFID situation and only much later did he let on that he was "powering" the card from an Output pin (instead of using 5V). So, I hope that you're not trying to "power" yours from an Output pin.

Second, there's a Red/Green LED on the card. It's Red till presented with a tag and then it goes Green. Is yours doing that much?

3

i an using 5v and ground for power. I the light on the reader starting green then goes red. when i open the serial monitor it displays rfid read write test and doesnt read the card or show any indication of reading it

4

this is the source of my code, There is no mention which Arduino is used. My pin 6 and Pin 8 are analog pwm pins. I have tried using the pin 18 tx and 19 rx along with the other tx/rx combos on the mega. I have also tried using straight digital pins. all give the came result. Im at a loss of ideas.

5

last thought for the moment, I appologize for being scatter brained, All I am out to do is read the card and verify it as good then do "X". Only been fighting this issue for a week now.

6

Darn.
I'm not gigging you, but you posted, "I recently bought a parallax rfid reader model 28440." So, I thought you were dealing with the "reader", the only one I've any knowledge of (the 28140.)
With your last posts, and looking at the site's page for it, I see that it's a reader/writer.
I do not have any good knowledge of the R/W.

7

All I know is I'm at a stand still and about 30 hours of research and tinkering with the code im at a stand still. From looking at spec sheets I didnt see any capatibility issues. I welcome any help i can get. The 5 boooks i looked at were od no help primarily they had no refference for interfacing the parallax rfid modules.

8

Hope you don't mind my refering to the Playground article --
http://arduino.cc/playground/Learning/ParallaxRFIDreadwritemodule

9

I have tried that code with no luck

10

I had the same problem u have right now (or maybe 120 days ago), but for reference, i think this code is not meant for arduino mega 2560 or adk, because i have it and tried this code but it didnt work but when i installed the parallax rfid module on an arduino uno it worked directly