In Part 1 of this series, we learned how to interface an organic light-emitting diode (OLED) display, using analog voltage (a potentiometer), with Arduino. In Part 2, we covered how to present data from an analog sensor — specifically, a light-dependent resistor (LDR) and soil moisture sensor — on an OLED display. In Part 3,…

 This project uses Sharp’s distance measuring sensors for exact distance measurement. Advanced measurement techniques make these sensors more reliable. [[wysiwyg_imageupload::]]They have higher precision since they are less influenced by the color and reflectivity of the reflected object. They use a focused beam to indicate the presence and location of an object in a particular range depending on the variant of the sensor. Typical ranges for different sharp sensors vary from 4 cm to 150 cm.The project works on the same principle as that of simple IR sensor based distance measurement. The analog output of the sensor is directly converted to digital by employing an ADC0804 interfaced with AT89C51.  The measured distance is also displayed on an LCD screen. This project is used for detecting humans and objects in several devices, security systems and robotics applications. It can be employed for sanitary purposes in electronic faucets, flush levers, soap dispensers etc. This project mainly consists of three units: a sensor unit, an ADC component and the LCD module.