I made an Infrared transmitter and receiver, but it seems to only work when shooting directly on. It uses TSAL7600 Infrared Led and a TSOP2438 38 MHz Infrared Receiver.
Any ideas to allow it to work better from multiple angles? Anyone add a lens?
What power are you putting out from your diode? You could try reducing the resistor and driving it harder.
On the receiver supply decoupling close to the chip is very important for this device. Have you followed the arrangements shown in the application circuit on page 1 of the data sheet. If not that will reduce the sensitivity.
Finally as you made the transmitter is the pulse rate right for the device. You should get at least an 6ft range over 45 degrees with this.
To make it omni directional take a piece of perspex and drill a hole half way through it. Mount the received pointing into this hole and mount the whole thing at horizontally.
38 MHz
You sure about that?
You sure about that?
yep - give or take three orders of magnitude. 
"To make it omni directional take a piece of perspex and drill a hole half way through it. Mount the received pointing into this hole and mount the whole thing at horizontally. "
I assume perspex is English for acrylic or plexiglass. Does it matter the shape of the perspex, like would a 1" circle with the led mounted in the center work? I guess this is like a poor man's lense.
I assume "lense" is American for "lens".
I played around with this and it seems better at night w/o sunlight coming in through the window and most lights off.
Overall there was about a 90 degree range that worked from 6 feet. This suggests the issue is with the receivers noise suppression.
I was thinking of trying a few receivers with different noise reduction. The retrievers have the same 3 connections, so they are easy to try. (The biggest hurdle is the cost of the shipping.) These are the receivers, I was thinking of trying: TSOP4838, TSOP34838, TSOP8238 and TSOP1138.
Also would like to try tsal7200. It is supposed to have greater range.
Any suggestions on receivers and emitters is appreciated.
Does it matter the shape of the perspex, like would a 1" circle with the led mounted in the center work?
It would work even better if you did it with a rod, because the sides would be polished.