Looking for a fun and educational pentesting project that blends hardware hacking and wireless experimentation? Meet Cypher Jammer – a compact, open-source jamming device designed to disrupt 2.4GHz signals including Bluetooth and Wi-Fi, powered by an ESP32-WROOM-32D and up to two NRF24L01+PA+LNA modules.

Whether you’re a hardware enthusiast, a cybersecurity researcher, or just a Flipper Zero fan, this little board is your new favorite sidekick.

What Is It?

The Cypher Jammer generates noise across the 2.4GHz spectrum, effectively jamming Wi-Fi and Bluetooth devices within range. It’s a pure educational and experimental tool aimed at helping you understand RF interference and channel saturation.

Important Disclaimer: Wireless jamming is illegal in many countries. This device is meant strictly for controlled environments, testing, and educational use. Know your local laws before operating.

Inspired by Noisy Boy

This project owes a big thanks to the talented Smoochie, creator of the well-known Noisy Boy project. In fact, this PCB mirrors Noisy Boy’s pin layout, making it fully compatible with his firmware. So if you’ve tested Noisy Boy, you’ll feel right at home here.

What You’ll Need

• 1x ESP32-WROOM-32D (or other ESP32 dev board)
• 1 or 2x NRF24L01+PA+LNA modules
• 1x Capacitor (between 10µF and 100µF depending on your NRF module)
• Optional: 1x DIP switch – for channel hopping patterns
• Optional: 2.4GHz RF amplifier – for extra range

Pin Configuration

For Dual NRF24:

• HSPI:
  • SCK: GPIO 14
  • MISO: GPIO 12
  • MOSI: GPIO 13
  • CS: GPIO 15
  • CE: GPIO 16
• VSPI:
  • SCK: GPIO 18
  • MISO: GPIO 19
  • MOSI: GPIO 23
  • CS: GPIO 21
  • CE: GPIO 22

For Single NRF24, choose either HSPI or VSPI.

Optional DIP switch can be attached to GPIO 33 for custom pattern control.

How to Upload the Code

No need to fumble around with Arduino IDE if you don’t want to. Use the WebFlasher for a fast and easy upload. Just open the installer in Chrome or Edge, select your port, choose between HSPI, VSPI, or Dual mode, and flash away.

Prefer manual uploading? Download the code, make sure you install the required libraries:

• RF24
• ezButton

Pro Tips & Features

• Channel Coverage:
  • NRF24 supports up to 125 channels
  • BLE: 40 channels
  • Bluetooth Classic: 80
  • Wi-Fi: Channels 1–14
• You can modify these ranges in the code to target specific devices or expand scanning.
• Want to tweak payload size? Look inside RF24.cpp around line 1972.

Performance Notes

• Tested on Bluetooth 5.0 and 5.3 devices – effective up to 10 meters.
• Adding an RF amplifier can greatly extend the effective jamming range.
• Performance depends on the environment, signal strength, and Bluetooth version.

PCB + Deal

You can grab the Cypher Jammer PCB from PCBWay and even score a $10 coupon to start your build:

Order here

Support & Credits

This project is free and open-source. If you found it helpful or modified the code, credit the original author – and consider donating to support future development.

Special thanks to:

• AtomNFT
• ParrotStore
• Sok Ponleu
• Philipp Simon

Support via PayPal or GCash – details on request.

Final Word

The Cypher Jammer is a must-have tool for anyone curious about wireless jamming, RF protocol fuzzing, or just experimenting with NRF modules and ESP32s. It’s lightweight, budget-friendly, and adaptable to your setup – even integrates nicely with Flipper Zero and other custom tools.

Whether you’re jamming for education, testing, or research, this open-source project gives you the foundation to explore, modify, and improve.

Visit https://github.com/dkyazzentwatwa/cypher-jammer

The post Meet the Cypher Jammer – The Open-Source Wireless Jamming Toolkit appeared on Hamradio.my - Amateur Radio, Tech Insights and Product Reviews by 9M2PJU.