Radio Telemetry is the process of data communication using the radio waves. It is used in many applications where it may be necessary to read signals from environmental sensors or to control a device or a piece of hardware remotely. Typical application areas of radio telemetry are in factory automation, robotics, medical applications, environmental monitoring and so on. In environmental monitoring it may be required to measure various environmental parameters, such as temperature, humidity, atmospheric pressure, pollution level, wind speed, wind direction etc. using a remote station to transmit the collected data to a main receiving station for processing.
Most radio telemetry applications are based on the Low Power Radio (LPRA) or Short Distance Radio (SDR) techniques. In general, most of these applications use the permitted un-licensed frequency bands, where communication power and range are limited to several hundred milliwatts and to several kilometres or less respectively.
Nearly all radio telemetry applications use some kind of processor to read, format, and transmit/receive the data. Because of their low cost and high processing power, microcontrollers or microprocessors are commonly used in most radio telemetry applications.
This book is written for students, for practising engineers, and for hobbyists who want to learn more about radio telemetry applications and microcontroller programming using the PIC18F series of microcontrollers. The design of a radio telemetry based mini weather station is considered as an example system in the book where the developed system can measure the temperature, humidity, atmospheric pressure, altitude, dew point, carbon monoxide level, nitrogen dioxide concentration, air quality level, wind direction, and wind speed.
The book has been written with the assumption that the reader has taken a course on digital logic design, and has been exposed to writing programs using at least one high-level programming language. Although not essential, knowledge of the C programming language will be useful. Also, familiarity with at least one member of the PIC series of microcontrollers (e.g. PIC16 or PIC18) will be an advantage. The knowledge of assembly language programming is not required because all the projects in the book are based on using the C language.