I need an IR receiver that can directly be used with a microprocessor – the TSOP series from Vishay seems to fit well and there are enough tutorials and software libraries to make use of it. Unfortunately in my design I only have space for a normal 3mm (preferably) or 5mm LED receiver diode. Is there a simple IR driver chip that works like the TSOP receivers but with an external IR diode? So it should have 4 pins (Vs, OUT, GND, LED-INPUT) instead of 3 pins, three of them (Vs, OUT, GND) to be used as IR receivers with build-in IR diode and the fourth to connect the diode to (and to GND, of course).
P.S: Maybe a bit more background about my actual project: I want to put an IR receivers into a LEGO® and/or DUPLO® bricks, such as shown in this project. The bricks shall receive signals such as "brick number 12, switch on", "brick number 7, send temperature" etc. from a TV remote control, from an IR keyboard and/or from a custom IR sender at the ceiling. There is enough space at least in a DUPLO brick for one or two additional microprocessors (e.g. ATtiny 13/45/85) and a few wires and resistors. The only possible solution I found so far is using transparent bricks.
Best Answer
Most IR Receivers have circuitry inside to strip the (typically) 38khz carrier wave used in IR remote applications. The Diode is closely matched to this, and is often encased in a shield to protect against noise. You would be hard pressed to find a different form factor.
What you can do, if the Lego brick only allows a typical 3 or 5mm led to be inserted, is use a piece of 3 or 5mm clear acrylic rod, cut to a short length and flame polished, inserted into the brick, with the IR receiver inside facing the rod. A cheap light pipe.