This IR-Reflex "bumper" can trigger on obstracles in an adjustable range of about 10cm to 1.5m on a radius of 180° or 90°, and discriminate the direction by 26° respectively 13° or better (half step). One scan is performed in about 1ms. Using the 90° variant allows the use of LEDs with narrower angle and thus up to 3m distance radius. As this is rather a low cost approach, the circuit is easy, using one AVR2313, 8 Transistors, 9 High Speed IR-LEDs and two TSOP7000, plus some red LEDs and very little electronics. The sensitivity is in part software controlable and thus adaptable to the parcour or environment an additional poti alows additional adjustment.
As this bumper is working as reflex coupler, it is not suitable for extreme black materials but "normal" black can be detected thanks to the extraordinary sensitivity of the TSOP7000 at reduced distance. The actual output is RS-232 @19.2 or 34.4 kBd, but using a bigger ATmega controller would allow I²C and 360°-view.. Photos and sheet coming soon, if there is interest. sigo