Unfortunately I selected an obsolete Sensor which is not produced anymore. Warning: This replacement suggestion works for the drehkino circuit, but is not a general replacement for APDS 9102.
original APDS 9102 cracked open (IR LED left, IR Receiver right), standard 3mm parts inside
There is a wide range of transmitters and receivers, I tested with matched ones for 950 nm:
- Osram SFH 409. It is not recommended for new designs though still available, Osram suggests using SFH 4346 as replacement
- Osram SFH 309 FA , pro: daylight filter, need to change series resistor R8 from 27k to 100k
- BPW 42
The enclosure is not needed, but it makes assembly easier:
I drew and ordered some of the enclosures as 3D-prints from shapeways using this STL: APDS_simple_nf.stl. A first test revealed that the black material is not tight for IR light, so I ordered the cheaper WSF material and added some extra light insulation with black heat shrink tube (Schrumpfschlauch), 3.2mm diameter before shrinking, so the receiver only sees the reflected light. The tube should shrink over the dome of the parts as seen in the photo, so that no stray light can escape to the side.
glue the optical parts to the enclosure
Orientation of the parts is very important. There is only one out of eight combinations correct (4x orientation, 2x position). Refer to the datasheets of the parts to locate anode and cathode of the IR-transmitter (LED) and emitter and collector of the IR-receiver (phototransistor). In the photo you see that the leg of the anode is longer than the cathode, and the emitter leg is longer than the collector wire of the photoransistor.