In this configuration, the LDR is connected between VCC and the output (A2 pin of Arduino) and a pull-up resistor of suitable value is connected between output and ground. The LDR sensor is connected in a pull-up configuration. The LDR is connected to pin A2 of the Arduino Pro Mini. The analog sensor used in this project is an LDR (Light Dependent Resistor). 1: Block Diagram of Arduino based Analog RF Data Transmitter Circuit Connections This project demonstrates reading the analog data from LDR sensor by an Arduino board and its transmission to another Arduino board which display the data in digitized form on an LCD screen. The read analog data can be serially out to an RF transmitter from any digital input/output pin. The digitization of analog data to a digital form can be performed using the open-source virtualWire library of the Arduino.

The Arduino microcontrollers which are most commonly used in hardware projects are also capable of reading the analog data and representing it to digital form. Like, the most sensors actually are analog sensors and they are capable of transmitting the analog data to a digital form only when a microcomputer process it from analog to digital form. The real world isn’t the digital, it is analog. In real-life situations, the source of digital data are only the computers, microcomputers or digital ICs. The circuits using RF modules for digital data transmission are simple and uses HT12E encoder and HT12D decoder ICs for parallel to serial and serial to parallel data conversion respectively.

The 434 RF modules are capable of transmitting 4-bit data along with the address byte. The transmission of digital data over an RF module is quite common.

Virtual wire arduino library