如何正确接收和发送来自 Arduino 的原始 IR 数据

Question

Following is my code to read the raw IR data from Arduino:

#define sprint Serial.print 
#define sprintln Serial.println
#include <IRremote.h>

#define IR_RCVR_PIN 11
IRrecv ir_receiver(IR_RCVR_PIN);
decode_results results;

void setup() {
    Serial.begin(9600);
    ir_receiver.enableIRIn(); // Start the receiver
}

void loop() {
   if (ir_receiver.decode(&results)) {
    dump(&results);
    ir_receiver.resume(); // Receive the next value
   }
}

int c = 1;

void dump(decode_results *results) {
   int count = results->rawlen;
   sprintln(c);
   c++;
   sprintln("For IR Scope: ");
   for (int i = 1; i < count; i++) {
       sprint("0x");
       sprint((unsigned int)results->rawbuf[i], HEX);
    sprint(" ");
   }

   sprintln("");
   sprintln("For Arduino sketch: ");
   sprint("unsigned int raw[");
   sprint(count, DEC);
   sprint("] = {");
   for (int i = 1; i < count; i++) {
       sprint("0x");
       sprint((unsigned int)results->rawbuf[i], HEX);
       sprint(",");
    }
    sprint("};");
    sprintln("");
    sprint("irsend.sendRaw(raw,");
    sprint(count, DEC);
    sprint(",38);");
    sprintln("");
    sprintln("");
}

Using that I can get this from a remote controller:

1
For IR Scope: 
0x47 0x1F 0xB 0x17 0xA 0x17 0xB 0x6 0xA 0x6 0xB 0x6 0xA 0x17 0xB 0x6 0xA 0x6 0xB 0x17     
0xA 0x17 0xA 0x7 0xA 0x17 0xA 0x7 0xA 0x6 0xB 0x17 0xA 0x17 0xA 0x6 0xB 0x17 0xA 0x17    
0xB 0x6 0xA 0x6 0xB 0x17 0xA 0x6 0xB 0x6 0xA 0x17 0xB 0x6 0xA 0x6 0xB 0x6 0xA 0x7 0xA     
0x6 0xB 0x6 0xA 0x6 0xB 0x6 0xA 0x7 0xA 0x6 0xB 0x6 0xA 0x7 0xA 0x6 0xB 0x6 0xA 0x6 0xB    
0x6 0xA 0x7 0xA 0x6 0xB 0x6 0xA 0x6 0xB 0x17 0xA 0x6 0xB 0x6 0xA 

For Arduino sketch: 

unsigned int raw[100] =       
{0x47,0x1F,0xB,0x17,0xA,0x17,0xB,0x6,0xA,0x6,0xB,0x6,0xA,0x17,
 0xB,0x6,0xA,0x6,0xB,0x17,0xA,0x17,0xA,0x7,0xA,0x17,0xA,0x7,0xA,0x6,
 0xB,0x17,0xA,0x17,0xA,0x6,0xB,0x17,0xA,0x17,0xB,0x6,0xA,0x6,0xB,0x17,0xA,
 0x6,0xB,0x6,0xA,0x17,0xB,0x6,0xA,0x6,0xB,0x6,0xA,0x7,0xA,0x6,0xB,0x6,0xA,
 0x6,0xB,0x6,0xA,0x7,0xA,0x6,0xB,0x6,0xA,0x7,0xA,0x6,0xB,0x6,0xA,0x6,0xB,
 0x6,0xA,0x7,0xA,0x6,0xB,0x6,0xA,0x6,0xB,0x17,0xA,0x6,0xB,0x6,0xA,};

So on sending this data I can use this instruction:

irsend.sendRaw(raw,100,38);

The problem is I cannot get any respond from the device I need to control. I already check my IR transmitter my reading is the same above.

Im I missing something?

Answer 1

You should take multiple reading of the signal, then average their values to remove little bias error. Be sure your emitter and receiver use the same light wavelength and to work at 38KHz (you are transmitting modulating at 38KHz. If your emitter does modulation for you, then you should not use IRremote).

Also, what do you expect as "response"? Normally, IR communication is one-way.

Answer 2

You are reaching the 100 bytes limit of RAWBUF, so you probably need to increase that number. Try going up to 400.

Open in IRemote.h and modify this line (about #122)

#define RAWBUF 100 // Length of raw duration buffer

to something bigger

#define RAWBUF 400 // Length of raw duration buffer

I'm tying your code with a Samsung air conditioner and I'm receiving 116 bytes

Answer 3

I just started playing with Arduino and was trying to replicate the code from my Pentax remote by doing what you did, but it wasn't working. Then I found this article: http://www.righto.com/2009/08/multi-protocol-infrared-remote-library.html . I says: "There are two differences between the raw buffers for sending and for receiving. The send buffer values are in microseconds, while the receive buffer values are in 50 microsecond ticks."

So all you need to do is multiply every element in your raw array by 50 and send those values in irsend.sendRaw(raw,100,38) . Worked for me.