As an automotive repair expert and content creator for keyfobprog.com, I’ve been diving deep into the Flipper Zero, a fascinating tool for many applications, including acting as a Key Fob Frequency Scanner. Recently, I investigated why the Frequency Analyzer feature within the Flipper Zero, specifically in firmware version 0.50.0, isn’t performing as users expect, particularly when it comes to scanning frequencies for key fobs.
After reviewing code pointed out by the community, it appears the current implementation of the Frequency Analyzer within the Flipper Zero firmware has some critical shortcomings. The core issue lies within the code responsible for signal detection and frequency scanning. Specifically, the subghz_scene_frequency_analyzer_on_event function, found in the subghz_scene_frequency_analyzer.c file, is designed in a way that it will always return false, effectively halting any signal detection notification.
Furthermore, and perhaps more fundamentally, the code lacks the essential logic to initiate a proper frequency scan. The Flipper Zero utilizes the CC1101 chip, which is capable of operating across a broad frequency range. However, the current Frequency Analyzer code doesn’t systematically step through these frequencies to identify signals. It doesn’t perform incremental scans (e.g., in 1MHz or 5MHz jumps) to measure the RSSI (Received Signal Strength Indicator) across the spectrum and pinpoint the strongest signal. This systematic scanning is crucial for any effective key fob frequency scanner to function.
In essence, the Frequency Analyzer, in its current state, doesn’t actively scan and analyze frequencies to provide meaningful feedback to the user. It’s not set up to methodically search for the highest RSSI across the available frequency ranges and present that information. As it stands, the chip and its associated library aren’t being instructed to “listen” across the entire frequency spectrum in a useful way for users trying to identify key fob frequencies.
This also highlights a potential limitation in the Read RAW function. Currently, it seems limited to reading preset, well-known frequencies. To be truly effective, especially for tasks like identifying unknown key fob frequencies, the Flipper Zero needs the ability to read and analyze any frequency within the CC1101 chip’s capabilities. This would empower users to use the Flipper Zero as a more versatile key fob frequency scanner and general RF analysis tool.
Moving forward, addressing these code deficiencies is critical to realizing the Flipper Zero’s potential as a useful key fob frequency scanner. Enhancements are needed to both the Frequency Analyzer and potentially the Read RAW function to enable comprehensive and effective frequency analysis. Hopefully, future firmware updates will incorporate these necessary improvements, making the Flipper Zero a more powerful tool for RF enthusiasts and professionals alike.
