Building an ESP32 Security Multi-tool

This project began as a cheap way to get a Flipper Zero, but it has given me a newfound love for hardware and OT. After seeing videos online of people making their own Flipper clones with an ESP32 and Marauder Firmware, I decided that it would be fun to make my own with custom firmware. Using AI, I created a firmware for the "Flipper32", and I am currently in the process of soldering everything together.

Hardware

The build is centered on an ESP32 microcontroller paired with an OLED display for on-device status and menu navigation, a CC1101 module for Sub-GHz radio work (garage remotes, sensors, and other ISM-band devices), and a PN532 module for NFC/RFID reading and emulation. Everything was assembled on a breadboard before moving to a more permanent enclosure.

Why This Matters for Security Work

A huge amount of physical and facility security still depends on Sub-GHz (gate remotes, wireless sensors) and NFC/RFID (badge access) technology that's rarely audited the way network infrastructure is. Building a tool that can read, analyze, and in some cases replay these signals is a fast way to understand why badge cloning and signal replay attacks are still realistic threats. Additionally, I learn about how mitigations (rolling codes, encrypted badges, reader tamper detection) actually defend against them.

Lessons Learned

This is a fun little project that has taught me about 3D Modeling, soldering, as well as a basic understanding of C++. After this project is done, I will be returning the the ESP32 world for more projects involving microcontrollers; I just had way too much fun with it.