Voltage output from IRLib

I guess this might be an stupid question putting my ignorance on full display but here it goes :

With the IRLib library, why is the output voltage at D3 only around 0.6V and not the full 5V? My understanding is that when that pin goes high, it should output board voltage.

I ask because I am trying to drive a IR LED that has a normal forward voltage of 1.3V and the 0.6V ain't cutting it.


Hi, and welcome to the forum.

IR LEDs for remote control are are pulsed. If you are trying to see this on a DMM, it will show you an average. e.g 10% of the time "on" and 90% of the time "off" will show 10% of the pin voltage (~0.5volt).

Make sure you use the right current limiting resistor (>= 100ohm) for your IR LED. Leo..

No code, no schematic and you want an answer?

Maybe the code is writing a pulse-train to pin 3 whose average voltage on a DVM is .6 volts. Maybe you have no led series dropping resistor. Everything is a guess until you decide to give more information to us.


Thanks Wawa. That answers my question. Makes perfect sense. Cheers.