Medium wave transmitter using only a PIC Microcontroller!

This is a MW/AM (1000KHz) transmitter using PIC Microcontroller CCP module generating 1MHz PWM signal with MCW (Modulated Continuous Wave) modulation. Demo music comes from the legendary Mario Bros video game.

The radiated signal is rich in harmonics up to 1Ghz. In this video you can see the 145MHz harmonic being received using a Yaesu VX-2 handheld amateur radio. It's so strong that you can hear the signal 20m away! Take in account that no impedance matching or serious antenna has been used for the demo. It's just a piece of wire to microcontroler's pin, so radiation is very poor, specially at low frequency.

After this proof of concept, i'm thinking on an application as simple and cheap LF RFID transmitter.

Category:

Science & Technology

Tags:

• MW
• MCW
• AM
• Transmitter
• PIC
• Microcontroller
• PWM
• CCP
• RFID
• RF
• Modulation

[6p1p]

Hi, What is the PIC model you are using for this experiment?

[eb4fbz]

pic18f2520

[grapetonix]

Great one. Add a mosfet plus driver and a better antenna, ramp it up to a watt or so maybe. I don't understand exactly - are you using the square wave from the CCP module straight off? Gotta be a signal full of spurs if so, for sure...

[eb4fbz]

You are right, as said on the description, i'm using the CCP square wave driving a piece of wire, so the radiated signal is full of harmonics and other spurs.

I could add some filtering and matching but this evening project was only for fun.

[noccy80]

Dude, great job! Sharing is caring, is it possible to get a copy of the schematics and the code? I am trying to get into PIC programming and basically learn how to do what you just did, but instructions are sparse :-) tia

[gery315]

lol super mario:D