Full Spectrum: the $499 kit that covers a car from 300 MHz to 5 GHz

2 Nov 2026 · 7 min read · Shop · Full Spectrum · Kit · Car

Spotter covers Wi-Fi on 2.4 and 5 GHz, and Bluetooth. The Pi and its RTL-SDRs cover everything below 1.7 GHz. Full Spectrum is both, with the two RTL-SDRs the Pi needs to do all its jobs at the same time, assembled and tested as one rig. It's the kit we run in our own car.

What's in the box

Every part is tested with every other part before it's boxed: both dongles found by serial, the sensor decoder and the sweep running together, the ESP32 pairing as the second companion, and the local pack for your area loaded on the Pi and checked against the phone.

Not included, because they depend on your car: the 12 V to 5 V converter and the powered USB hub. Both are in the car install guide with the specs that matter (5 V 3 A for a Pi 4; an externally powered hub, because two dongles and an ESP32 draw more than the Pi's ports supply). The roof antenna kit at checkout ($49: mag-mount antenna, 3 m SMA lead, free sealant; fits the RTL-SDR or a HackRF) puts the scanner antenna outside the metal, and the $99 case set adds a fitted case for every part and a hard carry case with cut foam for moving the rig between cars.

Three radios at once

Wavelens pairs with two companions: one main, one second. In the kit the Pi is the main (it carries the scanner audio and the sensor decoder) and the ESP32 is the second. With both paired, three radios feed the same screen:

• The phone does what it always did: BLE and Wi-Fi scans, GPS, the classifier, the map, the alerts.
• The ESP32 parks on the body-cam and hotspot channels with a real antenna and reports every beacon and advert there, from further out.
• The Pi names the sub-GHz world (whose tyre sensors are near you, which remotes and meters), sweeps the public-safety bands, follows trunked systems and tells you who holds the licence on a carrier.

The HUD shows one verdict from all of it. Rule hits counts what each radio contributed, which is how we know what the kit adds over a phone alone: on the same drive, the kit's rule hits run several times the phone's, mostly from the sub-GHz decoder and the parked ESP32.

Installing it

1. Power: buck converter on an ignition-switched circuit to the Pi; the hub's own supply to the hub.
2. Pi to hub on a short USB 3 cable (half a metre or less).
3. Each dongle on its own USB extension from the hub: dongle A to the dash with its whip, dongle B to wherever the roof antenna's coax comes in (keep the coax under 3 m; USB can be long, coax can't).
4. The ESP32 on a third extension or any USB port, antenna against glass.
5. Pair the Pi, then the ESP32, from More → Companion radio.

The wiring diagram shows all of it, including why the extensions matter: dongles run hot, block each other's ports, and pick up each other's oscillator noise side by side.

Growing it

The rig scales by USB port. A third RTL-SDR adds ADS-B aircraft. A HackRF (not something we sell; about $300 on its own) adds a 1 MHz to 6 GHz sweep that reaches 5.8 GHz video, 4.9 GHz public-safety links and cellular uplinks, labelled honestly as "something is transmitting here". The bridge already supports both; plug them in and set the roles.

What it doesn't do

Nothing in the kit transmits. It can't hear anything that talks only over cellular, or doesn't transmit at all, and an oncoming car at highway speed is usually out of range before one packet arrives; known weaknesses has the honest list. Radar and laser aren't receivable at all. The only link out is Bluetooth LE to your phone. Make sure you follow the laws where you drive; in some places detecting some devices is an offence, and a local pack switches those rules off where it applies.

Order Full Spectrum, $499

Next: The pre-configured RTL-SDR: what a $40 dongle with the right antenna actually does · all articles