PMRScan — Flipper Zero Application

Introduction

PMRScan is a Flipper Zero Sub-GHz scanning application designed to cycle through common PMR (Private Mobile Radio) frequencies in the 446 MHz band. It monitors signal strength (RSSI) and provides audio feedback through the Flipper speaker, allowing users to hear when a signal is detected.

When a signal above the configured sensitivity threshold is detected, scanning pauses and the signal is routed to the speaker. Press the OK (center) button to toggle scanning/lock behavior.

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Features

• Scans common PMR 446 MHz channels
• Real-time RSSI signal monitoring
• Audio output via Flipper speaker
• Auto channel scanning (up/down direction control)
• Adjustable sensitivity threshold
• Manual lock/unlock on detected signals
• Visual UI with channel + RSSI display

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Supported Frequencies

The app scans standard PMR446 channels:

446.00625 MHz
446.01875 MHz
446.03125 MHz
446.04375 MHz
446.05625 MHz
446.06875 MHz
446.08125 MHz
446.09375 MHz
446.10625 MHz
446.11875 MHz
446.13125 MHz
446.14375 MHz
446.15625 MHz
446.16875 MHz
446.18125 MHz
446.19375 MHz

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Installation

Requirements

• Flipper Zero
• Custom firmware with Sub-GHz API support
• Build environment (Flipper Zero SDK (Unleashed or OFW))

Build

git clone https://github.com/MeiosisKMZ/pmrscan/
cd pmrscan
./fbt fap_pmrscan

Install to device

./fbt flash_usb

Or drop the compiled (Released) .fap file for your firmware directly in ext/apps/Sub-GHz/

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Usage

1. Launch PMRScan from Flipper apps menu

2. Device begins scanning PMR channels automatically

3. When signal is detected:

   • Scanning pauses
   • Audio output is enabled

4. Press OK to lock/unlock scanning manually

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Troubleshooting

I don't have a walkie-talkie for the moment but I'm looking forward on testing my app against one. If any issues with the app not working, open an issue on Github.

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Project Structure

pmrscan/
│
├── pmrscan_app.c        # Main logic (scanning, UI, audio)
├── pmrscan_app.h        # App structure and declarations
├── README.md            # Documentation
├── LICENSE              # License
├── application.fam      # App informations
└── icons                
      └── pmrscan.png    # Fap icon

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License

LICENSE

The original work is from @thecybermind with FRSScan

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Happy Hunting !