Overview
The sensor consists of an IR LED and a photo sensor (phototransistor). The light emitted by the IR LED gets reflected by any object placed in front of the sensor and this reflection is detected by the photo sensor (phototransistor). Any white (or lighter) colored surface reflects more than black (or darker) colored surface.
When the reflected light is detected, it produces Digital HIGH (or Binary 1) output on the Sig pin. The on-board LED indicator will also glow. If no reflection is detected or if the object is too far from the sensor, the output on the SIG pin stays at Digital LOW (Binary 0). The on-board LED indicator will be off as well.
The detectable range of this sensor is 4–16 mm. The module incorporates a Rail-to-Rail Operational Amplifier to amplify the output of phototransistor. There is a potentiometer which can be used to adjust the gain of the amplifier, that is, sensitivity of detection.
Get Inspired
A quick tutorial on how to interface the voice recognition module with few examples.
For people not familiar with American Sign Language (ASL), being able to recognize what certain hand motions and positions mean is a nearly impossible task. To make this process easier, Hackster.io user ayooluwa98 came up with the idea to integrate various motion, resistive, and touch sensors into a single glove that could convert these signals into understandable text and speech. The system is based around a single Arduino Nano board, which is responsible for taking in sensor data and outputting the phrase that best matches the inputs. The orientation of the hand is ascertained by reading values from the X, Y, and Z axes of a single accelerometer and applying a small change based upon prior calibration. Meanwhile, resistive flex sensors spanning the length of each finger produce a different voltage level according to the bend’s extent. At each iteration of the program’s main loop, a series of Boolean statements are evaluated to pick the phrase that best matches the current finger bends and hand orientation, and this data is then outputted via the UART pins to an attached Bluetooth® HC-05 module. The final component is a connected phone running a custom app that takes the incoming words from Bluetooth® and saves them for text-to-speech output when the button is pressed. To see more about this project, you can read ayooluwa98’s write-up here on Hackster.io.
