Work principle
AM Radio transmissions are based on a carrier signal which is modulated by the audio signal. It’s a very basic principle but prone to noise from the environment. Using the ESP32 it is really simple to generate an analog signal using the built-in DACs. With the provided code here just a wire as an antenna has to be connected to the pin 25 of the ESP32. The transmission will end up on the AM frequency ~835kHz.
Parts
The parts used here are the LOLIN32 and the ESP32 MiniKIT. But Any ESP32 board can be used.
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Where to get them
These links are the cheapest I could find and also supporting our work (affiliate). I also ordered my modules there
LOLIN32 Board (~$6.90)
ESP32 Mini KIT (~$7.58)
But there are also cheap modules on Amazon and eBay:
Amazon.com .ca .de .fr
Ebay 
.de .fr
The oscilloscope came quite handy this project. I really like it, check it out:
Amazon.com .de .ca .fr
Code
All projects and files can be found here:
https://github.com/bitluni/ESP32AMRadioTransmitter
Audio to header converter
You can prepare your sounds using Audacity
Datasheets
Similar Projects
Send me a message if you know of any similar projects