AM radio transmission using AVR

radio_circuitry

When you think about building a radio transmitter circuit, the first thing that comes in mind is it requires too many analog components. But wait a minute, this guy demonstrates an AM transmission using a microcontroller. The interesting part is it uses a plant as an antenna for transmission. This project is based on Atmega324 microcontroller, internally clocked at 8 MHz, and it generates a modulated AM signal using internal timers and counters. It uses TC1 timer/counter to generate a PWM signal of approximately 540 KHz. This is the carrier frequency. You know that before AM transmission, the high frequency carrier signal is modulated with a low frequency message signal. In this case, the carrier frequency is modulated by varying the duty cycle of the output PWM from 5% to 50% using TC0 timer/counter.


The modulated output from the microcontroller has square waves. A simple RLC resonant circuit can suppress the higher frequency components and change the square waves into sine waves. Now it is ready for transmission. The author tested it with a plant as an antenna, and worked well. Visit the link below to see more details about the project.


Read More

We recommend EasyEDA for circuit design and PCB prototype
Schematic Drawing to PCB Production, Just Need One Tool
Cheap PCB Prototype: 10 pcs 2 layers only $10, quick delivery, 100% E-test

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *