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[on:]

Good Day Everyone;

I am working one making up / down counter using two RFIDs (https://www.sparkfun.com/products/8419) and LED Matrix  (https://www.adafruit.com/product/555) I did successfuly program the first RFID and Led matrix and I am stick in connecting the second one and make the down counter could someone guide me on that. The code as below:

Code:

#include "HT1632.h"

#define DATA 2
#define WR   3
#define CS   4
#define CS2  5

int scrwrt =0;
int newtag =0;
// use this line for single matrix
HT1632LEDMatrix matrix = HT1632LEDMatrix(DATA, WR, CS);

int RFIDResetPin = 13;

//Register your RFID tags here
char tag1[16] = "50008FF398B4";
char tag2[16] = "5000B98D6206";

void setup(){
  Serial.begin(9600);
//Serial1.begin(9600);

  matrix.begin(HT1632_COMMON_16NMOS); 
  matrix.fillScreen();
  delay(500);
  matrix.clearScreen();


  pinMode(RFIDResetPin, OUTPUT);
  digitalWrite(RFIDResetPin, HIGH);

  matrix.print("on..");
  matrix.writeScreen();

}

void loop(){
  char tagString[13];
  int index = 0;
  boolean reading = false;

  if (scrwrt > 0)
  {
  matrix.clearScreen();
  matrix.setTextSize(1);    // size 1 == 8 pixels high
  matrix.setTextColor(1);   // 'lit' LEDs
  matrix.setCursor(0, 0);   
 
  matrix.writeScreen();
  if (scrwrt==1)
  {
  matrix.print("no");
  matrix.writeScreen();
  matrix.setCursor(0, 8);   // next line, 8 pixels down
  matrix.writeScreen();
  matrix.print("ident");
  matrix.writeScreen();
  }
  if (scrwrt==2)
  {
  matrix.print("emp:");
  matrix.writeScreen();
  matrix.setCursor(0, 8);   // next line, 8 pixels down
  matrix.writeScreen();
  matrix.print(tagString);
  matrix.writeScreen();
  }
  if (scrwrt==3)
  {
  matrix.print("stu:");
  matrix.writeScreen();
  matrix.setCursor(0, 8);   // next line, 8 pixels down
  matrix.writeScreen();
  matrix.print(tagString);
  matrix.writeScreen();
  }
 
  scrwrt=0;
  }

clearTag(tagString); //Clear the char of all value

  while(Serial.available()){

    int readByte = Serial.read(); //read next available byte

    if(readByte == 2) reading = true; //begining of tag
    if(readByte == 3) reading = false; //end of tag

    if(reading && readByte != 2 && readByte != 10 && readByte != 13){
      //store the tag
      tagString[index] = readByte;
      index ++;
    }
    scrwrt=1;
  }

  checkTag(tagString); //Check if it is a match
 
  resetReader(); //eset the RFID reader
}

void checkTag(char tag[]){
///////////////////////////////////
//Check the read tag against known tags
///////////////////////////////////

  if(strlen(tag) == 0) return; //empty, no need to contunue

  if(compareTag(tag, tag1)){ // if matched tag1, do this
    lightLED(2);
Serial.print("studant : ");
scrwrt =2;
  }else if(compareTag(tag, tag2)){ //if matched tag2, do this
    lightLED(3);
Serial.print("employee : ");
scrwrt=3;
  }

else{
  Serial.print("unknown : ");
  }
Serial.println(tag);
}

 
void lightLED(int pin){
///////////////////////////////////
//Turn on LED on pin "pin" for 250ms
///////////////////////////////////
  Serial.println(pin);

  digitalWrite(pin, HIGH);
  delay(250);
  digitalWrite(pin, LOW);
}

void resetReader(){
///////////////////////////////////
//Reset the RFID reader to read again.
///////////////////////////////////
  digitalWrite(RFIDResetPin, LOW);
  digitalWrite(RFIDResetPin, HIGH);
  delay(150);
}

void clearTag(char one[]){
///////////////////////////////////
//clear the char array by filling with null - ASCII 0
//Will think same tag has been read otherwise
///////////////////////////////////
  for(int i = 0; i < strlen(one); i++){
    one[i] = 0;
  }
}

boolean compareTag(char one[], char two[]){
///////////////////////////////////
//compare two value to see if same,
//strcmp not working 100% so we do this
///////////////////////////////////

  if(strlen(one) == 0) return false; //empty

  for(int i = 0; i < 12; i++){
    if(one[i] != two[i]) return false;
  }

  return true; //no mismatches
}

[Reply #1 on:]

You have done quite some good work, still some remarks to improve coding style.

remove the bulk of code from loop by defining 2 functions  e.g. updateDisplay()  and  checkSerial(). loop could become something like:

Code:

#define WAINTING 1
#define READING 2
etc

int state
void setup()
{
  ...
  state = WAITING
}
void loop()
{
  switch(state)
  {
    case WAITING:
      if (cardDetected()) state = READING;
      break;
    case READING:
      readSerial();
      if (strlen(input) == 12) state = READ;
      break;
    case READ:
      if (checkTag(input, tag1)) state = EMP;
      if (checkTag(input, tag2)) state = STU;
      break;
    case EMP:
      increase(var);
      state = WAITING;
      break;     
    case STU:
      decrease(var);
      state = WAITING;
      break;
  }   
  updateDisplay(state);
}

other functions

in the code above the loop is mostly controlling the state machine.