Infrared troubleshooting

Hello, I've been trying to use the IRremote library ( to read an infrared signal sent from a remote control and then an infra red LED to emit the code read to a device (TV, Home Theater, etc.).

It was very easy and simple to make the receiver work, however, the emitter doesn't seem to be working and I can't even tell if the emitter is in fact emitting, I tried to do a simple blinking on digital pin 3 with a regular LED and it blinks just fine, then I switched to an IR LED and tried to use my Iphone to try to see any sign of light with no luck.

Is there any other way I can try to see if my IR LED is emitting? I'm currently using an Arduino Nano to emit the infra red signal to my devices and an Arduino Mini to receive the signal from the remote control, reading the documentation I could find they use the digital pin 3 to emit the signal, so I connected D3 to a 220ohm resistor and the resistor to the bigger "leg" of the IR LED and the smaller leg I just grounded, I tried to switch them as well with no luck though.

Thanks in advance

Is there any other way I can try to see if my IR LED is emitting?

You could try pointing a phone camera at it. Check it first with a known working remote.

+1 on the camera.

Dropping the resistor value to 100 (or even 50) might help.

At 220R, you are getting about 4mA (or less) on average and 15mA peak going through the IR Led, which may not be enough. (assumes 5V Arduino, less if 3.3V)

The pin can deliver 20mA.

A better soulution would be to use an NPN transistor to drive more current (...via google)

Thanks AWOL and AnalysIR, I was trying to see through my phone’s camera but couldn’t see anything, now, switching to 100ohm I can see a very dim light glowing blue, the weirdest thing is that I tried to switch to a 50ohm resistor and the light disappeared again.
I believe that the strength of the light I can see through the camera has a direct impact on the range of the emitter, right? Because the recorded code isn’t working yet
Thanks again guys, gonna keep this post updated as I have any new result

UPDATE: it turns out Iphone has an IR filter on its camera, I switched to an older digital camera and finally saw the infra red light, it’s working with 100ohms and it’s quite bright, it wasn’t working on my TV because even though I was sending the right code, the number of bytes was incorrect (I was sending 20 instead of 32) and now the code worked
Thanks again everyone!