Feed the map with your own gear

Every way to put something on SparrowMap from hardware you own — planes, drones, police radio, speed radar, plate readers. Each one has a build route (cheap, DIY) and a buy route (plug it in). Prices are ballpark, US, mid‑2026.

Just want to buy and plug in? Skip to the plug‑and‑play picks — one recommended device per job, no building. Everything can run in a browser except a couple of things (and the easy fixes are there too).

The direction this is heading: plug‑and‑play, wireless, usable anywhere. A node gets its position from GPS (so no setup — it knows where it is), talks over LTE (so no wires to a router), and can run on solar + battery (so no wall power). Flash one image, power it on anywhere, and it registers itself. Everything below is a step toward that kit. Nodes already sign what they report, and moving one mints a new node — so a portable sensor is a first‑class citizen, not a hack.

Start here — one kit tests almost everything ~$120 + add‑ons

A single Raspberry Pi covers planes, police radio, and the plate/camera reader. Add an ESP32 for drones. Radar is the one thing that needs a real detector (its own section below).

Raspberry Pi 5 (4 GB) + case, PSU, SD card~$95

RTL‑SDR Blog V4 dongle + antenna (planes + police radio)~$40

USB GPS receiver (position anywhere)~$15

ESP32‑S3 dev board (drones, Wi‑Fi/BT sensing)~$10

Pi Camera 3, or any cheap IP camera (plate / housing reader)~$35

Later: 4G/LTE hat + 18650 battery + small solar panel (untethered)~$70

✈️ Planes & police aircraft easiest — do this first

Aircraft broadcast their position on 1090 MHz (ADS‑B), unencrypted by design. You just receive it. Police helicopters and fixed‑wing show up here; an orbit over one spot is the tell. SparrowMap already has an aircraft layer — a local receiver makes it yours and real‑time.

Build

RTL‑SDR + antenna on the Pi, run dump1090 / PiAware.
Our feeder posts government/orbit aircraft to the hub.

Cost on top of the base kit: $0. Proven by thousands of PiAware sites.

Buy

FlightAware Pro Stick Plus + 1090 MHz antenna ~$45.
Or a ready FlightAware/ADSB kit ~$100.

Legal — receive‑only. No transmitting.

🛸 Drones cheap, but only compliant drones

US law now makes most consumer drones broadcast Remote ID over Wi‑Fi and Bluetooth — the drone's position and the operator's. An ESP32 hears it. Local/state police drones must broadcast; federal can fly dark, and home‑built ones may not comply — so this is "drones that announced themselves," not every drone.

Build

ESP32‑S3 ~$10 running open‑source OpenDroneID / WiFi‑RemoteID firmware.
Reads BLE + Wi‑Fi Remote ID; forwards to the hub.

Same board the RF beta uses. No SDR needed.

Buy

Pre‑flashed Remote ID receiver / "drone scanner" board ~$30–60.
Phone apps (Drone Scanner, OpenDroneID) work too — no hardware.

Detecting is legal. Jamming a drone is a federal crime.

📻 Police radio partial — encryption varies

An RTL‑SDR + trunk‑recorder can follow P25 trunked police radio where it is unencrypted. That tells you there is activity in an area and what is being said — not a GPS pin. Many departments now encrypt, so coverage is spotty. Check your county's encryption before investing time.

Build

1–2 RTL‑SDR dongles on the Pi, trunk‑recorder + a talkgroup list.
Feed activity/alerts to the map's scanner layer.

On top of the base kit: ~$25 for a second dongle.

Buy

A handheld digital scanner (Uniden SDS100) ~$550 — turnkey, but pricey.
Or link an existing Broadcastify feed (no hardware).

Receiving public‑safety radio is legal to listen to in most states; using it while committing a crime is not.

📡 Radar & speed traps the real‑time red dot

This is the new radar screen and map layer. A police speed gun emits microwave radar; a detector hears it. Ka band (33–35 GHz) is essentially police‑only — that is the clean signal. K band (24 GHz) now fires on modern cars' blind‑spot radar, and X band is mostly automatic doors, so those need corroboration.

Honest limit: one detector gives you band and strength, not coordinates. The accurate dot on a road comes from the strength peak as you drive past, a directional detector, or — best — several drivers seeing the same source, whose detection circles overlap onto the real spot. So the dot's confidence climbs with the network. And there is no cheap DIY build for a 34 GHz front end — the $200 detector already is that part.

Build (the bridge)

You still buy a detector; you build the data link.
tools/radar_bridge.py reads a Bluetooth detector's alerts + your GPS and posts them, authenticated by your node token.

Cheap 24 GHz doppler modules (HB100, CDM324) do not work — they detect motion, not police radar.

Buy (the detector)

Uniden R7 / R8, or Escort/Radenso with Bluetooth out ~$150–500.
Bluetooth is what lets the bridge read alerts automatically.

Radar detectors are legal in 48 states (not VA or DC, not on commercial vehicles / federal land). Radar jammers are illegal everywhere. We only detect.

No detector yet? Open /radar and tap Demo to see the scope work.

📷 Plate readers (ALPR) buyable and buildable

This is what SparrowMap's own camera does: read government / marked plates to map them — never civilians. You can buy a reader or build one for the price of a Pi and a webcam.

Build

Pi + camera + an open plate model (YOLO plate weights, CodeProject.AI, or PlateRecognizer's free tier) ~$80–150.
This is the SparrowMap node design — see Add a camera.

Buy

An LPR/ANPR IP camera (Reolink, Dahua, Hikvision) that reads plates onboard ~$150–400.
Point it at a road, feed it in via Add an IP camera.

Flock itself is subscription‑only and not sold to individuals.

🚗 Dashcams & your car's cameras every car is already a dashcam

The highest‑leverage version needs no new hardware: your phone in drive mode already captures the road and runs the detector. Actual dashcams vary a lot in whether software can reach their video.

Option	Can we tap it?	How
Your phone (drive mode)	Yes — best path	Already captures at speed; we can run detection on‑device and contribute automatically. No cost.
VIOFO (A139, A229…)	Yes	Publishes an RTSP stream + HTTP API over its Wi‑Fi. A Pi on that Wi‑Fi can pull frames, detect, and post. ~$130–200.
Novatek / Ambarella chip dashcams	Often	Many expose undocumented CGI endpoints (`cgi-bin/Config.cgi`, a feed on `:8192`) the community has mapped. Case by case.
WolfBox and most no‑name cams	No / unknown	Closed Wi‑Fi AP, no published RTSP or API. Joining it usually costs the phone its internet. Not worth buying to test.
Tesla / factory 360 cameras	No live access	Locked by the maker. TeslaCam is a USB dump after the fact, no live API. Not usable in real time.

Why not just plug in any dashcam? Browsers can't play RTSP, so it needs a small board (a Pi on the cam's Wi‑Fi) doing "detect locally, post over its own link." And pulling recorded files would put full video with plates intact across the boundary — exactly what SparrowMap refuses to do. The clean shape is always: detect on the device, ship a decision, not the footage.

🔌 The plug‑and‑play node the destination

Put the useful pieces on one board and you have a SparrowMap sensor you can drop anywhere:

Pi + camera — reads marked/government plates and (soon) spots ALPR‑camera housings.
RTL‑SDR — planes overhead and, where open, police radio.
ESP32 — drones that broadcast Remote ID.
GPS — it knows where it is, so there's nothing to configure.
LTE + solar/battery — no router, no wall power. Truly anywhere.

The blocker for the fully automatic "spot a Flock camera while driving and add it" step is a camera‑housing detector — that is the next build. Until it's proven, drive‑bys confirm known cameras automatically and only propose new ones to review.

Ready to set one up? Step‑by‑step guides for every option are on the setup page — radar, planes, drones, police radio — and all guides live at /guides.

Quick links. Radar → /radar + a Bluetooth detector. Cameras → Add a camera or Add an IP camera. Write your own → /contribute. RF gear on a phone/Pi/ESP32 → /rfbeta.

Legality note, US: receiving ADS‑B, Remote ID, and public‑safety radio is legal; transmitting on those bands or jamming is not. Radar detectors are legal for passenger vehicles except in Virginia and DC, and are barred on commercial vehicles and federal property. SparrowMap sensors only receive, and only government/marked vehicles are ever published. Prices are rough and change.