A WSPR multi-band beacon transmitter using an Si5351 and an ESP32-S3

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Jelle Kalf ed4a8c0f03 updating the readme		2026-01-22 17:50:00 +01:00
.vscode	Modifications:	2026-01-22 15:27:47 +01:00
src	Modifications:	2026-01-22 15:27:47 +01:00
.gitignore	Modifications:	2026-01-22 15:27:47 +01:00
main.cpp	some tweaks for esp8266 support	2026-01-22 17:07:22 +01:00
platformio.ini	some tweaks for esp8266 support	2026-01-22 17:07:22 +01:00
README.md	updating the readme	2026-01-22 17:50:00 +01:00

README.md

ESP32 (and ESP8266) WSPR Beacon

This project is related to a Tech Minds video on how to build a WSPR beacon using an Si5351 and an ESP32 module. The files wihtin this repo are for use with Visual Studio Code.

Like this project? Send me a dono here: https://buymeacoffee.com/techminds_matt

Hardware

Si5351
UK: https://amzn.to/3NM5uQk
US: https://amzn.to/4qOQD5X

ESP32-S3-N16R8
UK: https://amzn.to/4sDV05G
US: https://amzn.to/49By4v1

2W RF Amplifier
UK: https://amzn.to/4sHx9Ce
US:https://amzn.to/4jKjeHt

Device connectivity to Si5351

How to connect the Si5351 module to the various tested boards.

ESP32-S3-N16R8 connect the Si5351 with SDA to pin 8 and SCL to pin 9.
Generic ESP32-Wroom devkit connect the Si5351 with SDA to 21 and SCL to pin 22.
Generic ESP8266 connect the Si5351 with SDA to pin D2 and SCL pin D1.

Usage

Create a new PlatformIO project within Visual studio code, then replace main.cpp and platformio.ini with those in this repo. The board details wihtin the platformio.ini file are specific for the linked ESP32 module above.

Once firmware has been loaded onto ESP32 use a wifi device to connect to "TechMinds-ESP32WSPR". This is open, no password needed. Then navigate to: http://ESP32WSPR.local where you can change the wifi to connect to your home network, enter your callsign and assign a valid Maindenhead locator.