Detection range of IR much shorter than of TV

[JsBergbau]

First thanks for developing this great device.
I've build it and attached the signal output to active speakers. With that you can hear remote control of television when transmitting. In a quite dark room when facing the RC directly to IRis range is a few meters in which you can hear the RC. Despite it's digital output at some distance audio signal is clearly more quiet. Either signal is so weak that voltage output is lower or less impulses are detected so signal output is more quiet.

When putting IRis about 3.7 meters away from a window, facing at the window detection range is less than 50 cm. Detection range can be improved about 10 cm by applying a IR 760nm filter or putting a tube on, shielding the outside light, light the roles from toilet paper. There was no direct sunlight on IRis. Light measurement gave about 1200 lux at sensor angle. So it was not very bright and still range was reduced a lot.

I wonder how TVs can be remote controlled from a few meters distance even at very bright light conditions. So perhaps there is some possibility to increase detection range by using some technology like TVs do to increase detection range.

There is this cool project https://github.com/tb69rr/Iris using IRis to fingerprint smartphones. With higher detection range at daylight conditions it would get even more powerful.