FreeTrack Forum

I'm in the process of testing my circuit on some breadboard, but can't seem to get it working. I am using 4xAAA batteries (6V) connected in series to a 25R resistor and then 3 x SFH485P 880nm LEDs.



This should provide the LED's with around 60mA of forward current - plenty to ensure they're shing nice and bright.

The problem is, no matter what I use, they do not shine. I initially wired them up the wrong way around (assuming the long leg was the anode, arrghhh!!) but luckily I ordered 25 of them so I have plenty spare.

I am using an iPhone to see if they're working, but it's not showing anything. I have tried using the iPhone to look at a remote control but this shows nothing either - maybe the iPhone 4S camera is very good at filtering IR?

Does anyone know of a way of inserting a visible LED to the cuircuit as verification it's turned on? How would this affect the values?

Thanks!

It seems the Iphone has a good IR-filter. I used my Samsung Galaxy and the camera shows the IR when the leds are on.

Don't you have a normal digital camera you can use instead of your iPhone?

Otherwise darken your room and you should see a little dot of red licht in the led when you look very closely.

Thanks for the info, ill try setting up my Canon 650D on a tripod and connect that to the tv for testing. ill also try the PS3 Eye as well.

im determined to get this working before i go mad, but it may be too late  

It was working all along! In the end, I found an old CCTV camera (with IR) and hooked it up to the TV.