• Pin 1 is signal
• Pin 2 positive power
• Pin 3 is ground

Different Models have different pinouts. The raw vs18388 part has

Pinout Reminder (for VS1838B):

• IRRemote Library
• IRremote Tutorial

#include <Arduino.h>
#include <IRremote.h>

#define IR_RECEIVE_PIN 36

IRrecv IRReceiver(R_RECEIVE_PIN);
decode_results results;

void setup()
{
   Serial.begin(9600);
   IRReceiver.enableIRIn();


}

void loop() {
   if(IRReceiver.decode(&results)) {
      Serial.println(results.value, HEX);
      IRReceiver.resume();
   }

}

00000000111111110110100010010

00000000111111110110

The NEC protocol follows a specific timing pattern:

Header:

MARK: ~9000µs
SPACE: ~4500µs
32-bit Data (8-bit Address, 8-bit Inverted Address, 8-bit Command, 8-bit Inverted Command):

Each bit consists of:
MARK (~560µs)
SPACE (~560µs for 0, ~1600µs for 1)
End Signal:

MARK (~560µs)
Final SPACE (~40ms, if the key is held, FFFFFFFF is sent)

Observed pattern on Oscilliscope

Leader Code (Start Frame)

LOW for ~9200µs, then HIGH for ~4500µs Indicates the start of an IR transmission.

Bit Encoding

Every bit starts with a LOW pulse (~560-600µs). The following HIGH pulse determines if the bit is 0 or 1: Short HIGH (~500-600µs) → 0 Long HIGH (~1500-1700µs) → 1

00000000 11111111 01101000 10010111

Holding the Key
Instead of repeating the full command, the remote sends a repeat signal every 108ms.
The repeat signal consists of:
9ms LOW (MARK)
2.25ms HIGH (SPACE)
560µs LOW (MARK)
97ms HIGH (SPACE)
Key Release
No further signals are sent after the final repeat signal.