Arduino infrared problems

Forum 2005-2010 (read only) Hardware Interfacing
5

Hej,

this is my code for sender and receiver, note that the receiver is having a nasty hack to get the data out, but it sends and receives numbers from 1 to 8 with no problem :slight_smile:

RECEIVER
-----------------

int ir_pin = 7;                         //Sensor pin 1 wired through a 220 ohm resistor
int led_pin = 13;                           //"Ready to Receive" flag, not needed but nice
int debug = 0;                           //Serial connection must be started to debug
int start_bit = 2000;                   //Start bit threshold (Microseconds)
int bin_1 = 1000;                           //Binary 1 threshold (Microseconds)
int bin_0 = 400;                             //Binary 0 threshold (Microseconds)


void setup() {
 pinMode(led_pin, OUTPUT);             //This shows when we're ready to receive
 pinMode(ir_pin, INPUT);
 digitalWrite(led_pin, LOW);       //not ready yet
 Serial.begin(9600);
}

void loop() {
 int key = getIRKey();             //Fetch the key
 if (key != -1) {
   Serial.print("Key Recieved: ");
   Serial.println(key);
 }
}


int getIRKey() {
 int data[12];
 digitalWrite(led_pin, HIGH);     //Ok, i'm ready to recieve
 while(pulseIn(ir_pin, LOW) < 2200) { //Wait for a start bit
 }
 data[0] = pulseIn(ir_pin, LOW);       //Start measuring bits, I only want low pulses
 data[1] = pulseIn(ir_pin, LOW);
 data[2] = pulseIn(ir_pin, LOW);
 data[3] = pulseIn(ir_pin, LOW);
 data[4] = pulseIn(ir_pin, LOW);
 data[5] = pulseIn(ir_pin, LOW);
 data[6] = pulseIn(ir_pin, LOW);
 data[7] = pulseIn(ir_pin, LOW);
 data[8] = pulseIn(ir_pin, LOW);
 data[9] = pulseIn(ir_pin, LOW);
 data[10] = pulseIn(ir_pin, LOW);
 data[11] = pulseIn(ir_pin, LOW);
 digitalWrite(led_pin, LOW);

 if(debug == 1) {
   Serial.println("-----");
 }
 for(int i=0;i<11;i++) {                 //Parse them
   if (debug == 1) {
         Serial.println(data[i]);
   }
   if(data[i] > bin_1) {                 //is it a 1?
       data[i] = 1;
   }  else {
       if(data[i] > bin_0) {           //is it a 0?
         data[i] = 0;
       } else {
        data[i] = 2;                     //Flag the data as invalid; I don't know what it is!
       }
   }
 }

 for(int i=0;i<11;i++) {                 //Pre-check data for errors
   if(data[i] > 1) {
       return -1;                           //Return -1 on invalid data
   }
 }

 int result = 0;
 int seed = 1;
 for(int i=11;i>=0;i--) {                //Convert bits to integer
   if(data[i] == 1) {
       result |= seed;
   }
   seed = seed * 2;
 }

 //patch for the weird data result
 //I wish I knew wtf is wrong
 for (int j = 0; j <= 11; j++) {
 int aux = result;
   aux -= pow(2, j);
   if (aux < 0) {
     result = j;
     break;
   }
 }
 if (result > 8) result = -1;
 return result;                             //Return key number
}

SENDER
--------------

int ir_pin = 6;                         //Sensor pin 1 wired through a 220 ohm resistor
int led_pin = 13;                           //"Ready to Receive" flag, not needed but nice
int debug = 1;                           //Serial connection must be started to debug
int start_bit = 2400;                   //Start bit threshold (Microseconds)
int bin_1 = 1200;                           //Binary 1 threshold (Microseconds)
int bin_0 = 600;                             //Binary 0 threshold (Microseconds)
int dataOut = 0;
int guardTime = 300;


void setup() {
 pinMode(led_pin, OUTPUT);             //This shows when we're ready to recieve
 pinMode(ir_pin, OUTPUT);
 digitalWrite(led_pin, LOW);       //not ready yet
 digitalWrite(ir_pin, LOW);        //not ready yet
 Serial.begin(9600);
}

void loop() {
 if (Serial.available()) {
   int val = Serial.read();
   switch (val) {
   case '0':
     dataOut = val - 48;
     break;
   case '1':
     dataOut = val - 48;
     break;
   case '2':
     dataOut = val - 48;
     break;
   case '3':
     dataOut = val - 48;
     break;
   case '4':
     dataOut = val - 48;
     break;
   case '5':
     dataOut = val - 48;
     break;
   case '6':
     dataOut = val - 48;
     break;
   case '7':
     dataOut = val - 48;
     break;
   case '8':
     dataOut = val - 48;
     break;
   default:
     dataOut = 255;
     break;
   }
 }
 int key = sendIRKey(dataOut);             //Fetch the key
 Serial.print("Key Sent: ");
 Serial.println(key);
}


int sendIRKey(int dataOut) {
 int data[12];
 digitalWrite(led_pin, HIGH);     //Ok, i'm ready to send
 for (int i=0; i<12; i++)
   data[i] = dataOut>i & B1;   //encode data as '1' or '0'

 // send startbit
 oscillationWrite(ir_pin, start_bit);
 // send separation bit
 digitalWrite(ir_pin, HIGH);
 delayMicroseconds(guardTime);
 // send the whole string of data
 for (int i=11; i>=0; i--) {
   //digitalWrite(ir_pin, LOW);
   //if (data[i] == 0) delayMicroseconds(bin_0);
   //else delayMicroseconds(bin_1);
   if (data[i] == 0) oscillationWrite(ir_pin, bin_0);
   else oscillationWrite(ir_pin, bin_1);
   // send separation bit
   digitalWrite(ir_pin, HIGH);
   delayMicroseconds(guardTime);
 }
 delay(20);
 return dataOut;                            //Return key number
}

// this will write an oscillation at 38KHz for a certain time in useconds
void oscillationWrite(int pin, int time) {
 for(int i = 0; i <= time/26; i++) {
   digitalWrite(pin, HIGH);
   delayMicroseconds(13);
   digitalWrite(pin, LOW);
   delayMicroseconds(13);
 }
}

/d