Analog Distance Sensor 20-150cm

Overview

3-pin JST cable connected to a Sharp analog distance sensor.

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 works with our 3-pin JST cables 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.

Feature summary

• 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)
• update period: 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. TheGP2Y0A02YK datasheet (703k 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).

Alternative Sharp Distance Sensors

We carry two shorter-range versions of this sensor as well: the Sharp GP2Y0A41SK0F analog distance sensor (4 – 30 cm) and the Sharp GP2Y0A21YK0F analog distance sensor (10 – 80 cm). These analog distance sensors have identical packages and pin-outs, making it easy to swap one version for another should your application requirements change. We also carry two digital Sharp distance sensors that have lower minimum detection distances, quicker response times, lower current draws, and much smaller packages; they are available with a 5 cm or 10 cm range and simply tell you if something is in their detection range, not how far away it is.

http://www.pololu.com/product/1137