Building ZeroTrace: An ESP32-S3 Hardware Companion for RF Auditing & USB-HID Security
April 15, 2026
Why Build ZeroTrace?
Modern cybersecurity audits often require a mix of wireless spectrum monitoring tools, USB endpoint testing devices, and RF telemetry trackers. ZeroTrace was created to unify these capabilities into a single, pocket-sized, self-contained embedded companion powered by the ESP32-S3 dual-core microcontroller.
Key Engineering Highlights
• 2.4 GHz RF & Wi-Fi Auditing: Non-blocking background promiscuous packet scanning, channel noise assessment, and live RSSI foxhunting with visual feedback.
• Deterministic USB-HID Payloads: Native hardware USB OTG stack enabling keystroke automation routines for vulnerability assessments without auxiliary USB dongles.
• Responsive Firmware Architecture: Written in modular C++ leveraging FreeRTOS multi-threading to guarantee that 60 FPS display rendering on the ST7735 TFT screen never drops a packet.
• Deterministic USB-HID Payloads: Native hardware USB OTG stack enabling keystroke automation routines for vulnerability assessments without auxiliary USB dongles.
• Responsive Firmware Architecture: Written in modular C++ leveraging FreeRTOS multi-threading to guarantee that 60 FPS display rendering on the ST7735 TFT screen never drops a packet.
Firmware Task Architecture
main_dispatcher.cpp
1// ZeroTrace FreeRTOS Dual-Core Architecture
2void app_main() {
3 // Core 0: Wireless Promiscuous Sniffing & RF Spectrum Calculations
4 xTaskCreatePinnedToCore(vTaskRFEngine, "RF_Task", 8192, NULL, 3, NULL, 0);
5
6 // Core 1: Low-Latency ST7735 UI Rendering & ADC Joystick Handling
7 xTaskCreatePinnedToCore(vTaskDisplayUI, "UI_Task", 4096, NULL, 2, NULL, 1);
8}Open Source & Future Work
ZeroTrace is currently being evaluated for advanced signal resilience tests and design patent filing. You can inspect the firmware, circuit designs, and hardware build documentation on the official GitHub repository.
#esp32-s3#embeddedsecurity#rfspectrum#freertos#usb-hid#hardwareaudit