SubCar is a receiver app for decoding automotive remote keyless entry (RKE) signals from car key fobs. It passively listens on a configurable frequency and attempts to match incoming signals against a library of known manufacturer protocols, displaying decoded results in a scrolling list.

Settings

• Frequency: Default is 433.92 MHz, the standard European RKE band. Adjustable via the encoder knob or on-screen numpad for other regional bands (e.g., 315 MHz in North America).
• RF Amp (0 or 1): Enables/disables the internal RF amplifier.
• LNA gain (0–40): Low-noise amplifier gain. See Receive Quality Issues.
• VGA gain (0–62): Variable-gain amplifier gain. See Receive Quality Issues.
• Mode: Selects the demodulation mode — AM (default) or FM. Most car key fob protocols operate with AM (OOK) modulation; FM mode may be needed for some regional or newer implementations.
• Clear: Clears the decoded signal list from the display (does not affect the log file).
• Log: When checked, decoded packets are written to a timestamped CSV file on the SD card: LOGS/SubCarLOG_YYYYMMDD_HHMMSS.CSV. The file header is ; Type; Bits; Data;.

Decoded Signal List

Each decoded packet is shown as a row with three columns: Type (protocol name), Bits (bit length of the decoded frame), and Age (seconds since last received). The list is deduplicated by signal content — repeated presses of the same fob button update the age counter rather than adding a new row.

Selecting an entry opens a detail view showing the protocol type, serial number, button code, and additional decoded fields where available for that protocol.

Supported Protocols

The following car key fob protocols are currently implemented:

Protocol	Manufacturer
Suzuki	Suzuki
VW	Volkswagen (button IDs: Lock, Unlock, Trunk, Panic, combinations)
Subaru	Subaru
Kia V0–V5	KIA
Ford V0	Ford
Fiat V0	Fiat
BMW V0	BMW

Note: Some protocols with full rolling-code encryption (Kia V6, PSA/Peugeot-Citroën) are recognized but not decoded, as the payload is entirely encrypted.

Settings Persistence

The modulation mode and Log checkbox state are saved to rx_subcar.ini on the SD card when App Settings is enabled in the global Settings menu