Mayhem — Capabilities

Mayhem organizes its features as a grid of applications launched from the main menu, grouped into receivers, transmitters, transceivers, capture and replay, utilities, and games. This volume catalogues them. The list reflects the application set documented on the project wiki as of September 2026, matching the contemporaneous nightly builds; Mayhem adds and renames apps often, so treat any single list as a snapshot rather than a fixed specification.

A structural fact frames everything below: the HackRF One is half-duplex and tunes roughly 1 MHz to 6 GHz. Any app either receives or transmits at a given moment, and the same wide front-end serves them all.

2.1 Receive applications

The receiver set is the largest and least legally fraught part of the firmware (receiving is broadly lawful in most jurisdictions; see the legality section). It spans general-purpose tuners and a long list of protocol-specific decoders:

• General reception — a broadband Radio receiver (AM/FM/SSB/wideband), audio receivers, a Scanner, a Search function, a Signal Hunter and a Level meter, plus Looking Glass, a wide-span spectrum survey.
• Aviation and maritime — ADS-B (aircraft transponders), AIS (ship transponders), VOR (aviation navigation).
• Paging and data — POCSAG and FLEX pager decoders, ACARS (aircraft messaging), APRS (amateur packet), AFSK, RTTY, Morse, 2-Tone, and TETRA reception.
• Telemetry and sensors — TPMS (tyre-pressure sensors), ERT (utility meters), Radiosonde and Meteor/NOAA/WeatherFax weather reception, and generic OOK/sub-GHz decoders.
• Imaging and novelty — SSTV (slow-scan TV), an analog TV receiver, a BLE (Bluetooth Low Energy) receiver, an NRF24L01 decoder, an EPIRB distress-beacon receiver, and small tools such as a spectrum Detector and ProtoView.

2.2 Transmit applications

The transmit set mirrors many of the receive decoders with encoders, plus tools that generate specific signals. Whether any of these may lawfully be used is governed entirely by the band and the operator’s licensing — see the legality section, which applies to this whole list. The apps include:

• Signal generation — a Signal Generator, Tuner, OOK (with an editor and brute options), a Soundboard and Microphone transmitter, Spectrum Painter (paints an image into the waterfall), and Jammer.
• Encoders paired with the receivers — ADS-B TX, APRS TX, POCSAG TX, FLEX TX, RTTY TX, Morse TX, 2-Tone TX, SSTV TX, RDS (FM radio data), P25 TX, MDC-1200, SAME (weather-alert tones), and EPIRB TX.
• Remote and key protocols — KeeLoq TX, Security+ TX, Key Fob TX, TouchTunes, TEDI/LCR, and a FlipperTX app that replays .sub sub-GHz files.
• GPS and Bluetooth — a GPS simulator, BLE TX and BLE-advertisement spam tools.

2.3 Transceivers, capture and replay

• Transceivers — a Microphone transceiver (push-to-talk voice) and a KISS TNC for packet radio.
• Capture — records raw IQ samples to the SD card in the HackRF .C16 format (and related .C8/.CU8), with metadata alongside. This is the record-anything primitive: capture a slice of spectrum for later analysis or replay.
• Replay — transmits a previously captured IQ file back out, the basis of capture-and-replay work. Replay is a transmit operation and carries every one of the legal constraints below.

2.4 Utilities and extras

The Utilities menu carries the housekeeping and workshop tools: a File Manager, the Flash Utility (on-device firmware updates, Volume 3), a Frequency Manager, SD Over USB, an Antenna Length Calculator, a Waterfall Designer, Notepad, a WAV Viewer, Wipe SD Card, and more. Mayhem also ships a set of small games (Doom, Snake, Tetris and others) that are incidental to its purpose but part of the shipped image.

External applications (files with the .ppma/.ppmp extensions) can be added on the SD card and appear in the menu without rebuilding the firmware; this is how the project ships less-central apps without bloating the flashed image.

2.5 Transmitting is regulated

Receiving with a HackRF and PortaPack is broadly lawful in most jurisdictions — listening to, analyzing and decoding signals is generally treated as permitted. Transmitting is a different matter and is legally restricted. Mayhem’s own “Intended Use and Legality” documentation puts it directly: in general it should be assumed that transmitting radio signals is not legal without authorization. The main lawful exceptions are narrow:

• ISM bands are licence-free in most jurisdictions provided power limits and other conditions are met.
• Amateur radio bands are available to operators who hold the appropriate licence (in the United States, an FCC amateur licence under Part 97), and only within the terms, band plans and power limits of that licence.

Outside those, transmitting is generally an offence. The HackRF One is not certified as an intentional radiator by the FCC, CE or ISED, and transmitting on cellular, aviation, emergency or other protected bands is unlawful and can carry substantial penalties or equipment seizure. Several apps in the transmit list (jammers, GPS simulation, key-fob and remote replay) have essentially no lawful use against equipment the operator does not own. The practical reference rule the firmware’s documentation gives is to only ever transmit where explicitly permitted, into a dummy load or a shielded enclosure for bench work, and to confirm the rules for one’s own jurisdiction — this dive is not legal advice. The owner is in Michigan, United States, where the FCC framework governs.

Continue to Volume 3 for installation and the update flow.