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 20 cm to 150 cm (8″ to 60″); a plot of distance versus output voltage is shown below.
The GP2Y0A02 uses a 3-pin JST connector that connects to our 3-pin JST cable for Sharp distance sensors (not included) as shown in the top picture on the right. It is also simple to solder three wires to the sensor where the connector pins are mounted (see the lower picture to the right). When looking at the back, the three connections from left to right are power, ground, and the output signal.
- operating voltage: 4.5 V to 5.5 V
- average current consumption: 33 mA (typical)
- distance measuring range: 20 cm to 150 cm (8″ to 60″)
- output type: analog voltage
- output voltage differential over distance range: 2.0 V (typical)
- response time: 38 ± 10 ms
- package size: 29.5×13.0×21.5 mm (1.16×0.5×0.85″)
- weight: 4.8 g (0.17 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 GP2Y0A02YK data sheet 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).
Alternative Sharp Distance Sensors
There are shorter-range versions of this sensor as well: the Sharp GP2D120XJ00F analog distance sensor (4 – 30 cm) . These analog distance sensors all have identical pin-outs and very similar packages, making it easy to swap one version for another should your application requirements change. We also sell a digital Sharp distance sensor, which has a very low minimum detection distance, quicker response time, lower current draw, and a much smaller package.
Note: The manufacturer recommends you insert a bypass capacitor of 10 uF or more between Vcc and GND near this sensor to stabilize your power supply line.