The Sharp distance sensors are a popular choice for many projects that require accurate distance measurements. This IR sensor is more economical than sonar rangefinders, yet it provides much better performance than other IR alternatives. Interfacing to most microcontrollers is straightforward: the single analog output can be connected to an analog-to-digital converter for taking distance measurements, or the output can be connected to a comparator for threshold detection. The detection range of this version is approximately 4 cm to 30 cm (1.5″ to 12″).
The GP2Y0A41 uses a 3-pin JST PH connector (now included with unterminated wires on the other end).
- Operating voltage: 4.5 V to 5.5 V
- Average current consumption: 12 mA (note: this sensor draws current in large, short bursts, and the manufacturer recommends putting a 10 µF capacitor or larger across power and ground close to the sensor to stabilize the power supply line)
- Distance measuring range: 4 cm to 30 cm (1.5″ to 12″)
- Output type: analog voltage
- Output voltage differential over distance range: 2.3 V (typical)
- Update period: 16.5 ± 4 ms
- Size: 44.5 mm × 18.9 mm × 13.5 mm (1.75″ × 0.75″ × 0.53″)
- Weight: 3.5 g (0.12 oz)
Linearizing the output
The relationship between the sensor’s output voltage and the inverse of the measured distance is approximately linear over the sensor’s usable range. The GP2Y0A41SK0F datasheet (1MB pdf) contains a plot of analog output voltage as a function of the inverse of distance to a reflective object. You can use this plot to convert the sensor output voltage to an approximate distance by constructing a best-fit line that relates the inverse of the output voltage (V) to distance (cm).