Long range IR led at 38khz n555 timer Vs TSOP38khz

Other Hardware Sensors
1

Hi,

Project Intro

My project is to build an IR emetter-receiver system linked to my arduino to make the shooting system of an arduino based laser tag game.

I noticed that the TSOP2238 I'm using can receive IR pulse from standard remote control (15 meters easily approx 49ft).

Datasheet of the TSOP2238 used in this project

The receptor

I built a small circuit with an arduino uno, this receptor and a led which switches on when the TSOP receive an IR signal at 38khz:

The code for the receptor is as follow:

int ledR=7;
int IRReceiver=8;

void setup() {
    pinMode(ledR,OUTPUT);
    pinMode(IRReceiver,INPUT);
    digitalWrite(ledR,LOW); //eteint
}

void loop() {
    bool reception=digitalRead(IRReceiver);
    if(reception==true){
        digitalWrite(ledR,HIGH);
    }
   else{digitalWrite(ledR,LOW);}
}

When I point a standard remote control at it it works perfectly so I guess there is no problem on the receptor side.

The emetter

At first I only used a n555 timer with a matching IR led. I used a 10uF capacitor, R1=1100Ohm, R2= 1330Ohm

Datasheet of the n555 timer used in this project

The cicrcuit is as follows:

The problem

Yet this doesn't really work, where I had a bright red led with a remote control on the receptor, now it only fades and have a much smaller range (10 centimeters approx 0.33 ft).
After checking forum and websites about the topic (such as this very good one )
I noticed that this 38khz signal should be modulated at at a low frequency approx 30 hertz. I did this with the tone function of my arduino nano. The red witness led still switches on at small range (still 10centimeters approx 0.33 ft) but more briglthy so I guess it's better. But when the led is straight forward oriented to the detector, the red witness led doesn't switches on. Indeed, i must put some angle between the receptor and the IR led to recieve the signal.
Have you tips on how have a bigger range (such as a remote control) ?

Thanks a lot,

An arduino and electronic noob,

2

The signal (data) you want to send is to be modulated onto the 38kHz carrier (OOK)
check the current in your transmitter. You may need 50mA+

3

Thanks, Indeed there is modulation needed for this 38khZcarrier. I tried to modulate it with frequency from 10Hz to 100 Hz (10 ,16 30,90 Hz) But none yielded a correct result.
Thanks for the tips of current checking, I will try to use an amplifier such as this one I found on Instructable. I'll post the result here.

Credits to j44 for his awesome work on laser duino tagger.

4

You might find this circuit useful....you can control the amount of current by changing the base resistor.

Constant current infrared LED emitter circuit