# Telltale — 6 kits, what to buy Six ready-to-order bundles, cheapest → most capable. Prices are indicative NZD **as at September 2026** and move around — re-check before quoting one to a club; links are to **named products** and **stable search queries** rather than throwaway listing IDs (those die). Cross-reference the parts detail in `AIS-HOME-STATION.md` and the wiring in `CLUB-DEVICE-SPEC.md`. > **Rule of thumb:** one **Shore station** per club (records the AIS fleet), then **phones** for the > non-AIS fleet, and a **boat gateway** only for boats that want their own wind/heel/speed in the replay. --- ## 1. Phone only — NZ$0 The `/track` page (position) or `/relay` page (position + BLE instruments). No hardware. - **Buy:** nothing. Open **telltaleracing.com/track** on any phone. - **Covers:** dinghies, sportboats, any boat without AIS. Position-only replay. ## 2. Boat gateway, 0183 — the ~NZ$8 ESP32 ⭐ cheapest hardware Reads the boat's two 0183 wires and re-serves NMEA over WiFi (UDP+TCP+BLE) to every phone/OpenCPN at once. Flash `firmware/telltale_gateway/telltale_gateway.ino`. - **ESP32 WROOM-32 dev board** (~NZ$5) — AliExpress search: · Amazon: - **RS-422 / MAX3485 level converter** (~NZ$2–3) — AliExpress: (a MAX485 module works for receive-only) - **Dupont jumper wires + USB power** (~NZ$3) — most people already have these. - **Covers:** one boat's OWN instruments (+ its own AIS if on the 0183 bus). Not the wider fleet. - **Note:** instruments are 4800 baud; a separate AIS 0183 output is 38400 — set `NMEA_BAUD` to match, or use two ESP32s. ## 3. Boat gateway, NMEA-2000 — ~NZ$10–14 ⭐ truly plug-and-play, no wiring The easiest box of all. N2K uses standard Micro-C **plugs** and **T-pieces** — plug a tee into the backbone, plug this box into the tee, and it powers itself off the bus's 12V. **One plug = data + power. No wiring.** Flash `firmware/telltale_gateway_n2k/telltale_gateway_n2k.ino` (decodes N2K → re-emits 0183 over WiFi). - **ESP32 WROOM-32 dev board** (~NZ$5) — as kit #2. - **SN65HVD230 CAN transceiver** (~NZ$1) — the only added part vs the 0183 box: - **M12 Micro-C field-attachable plug or pigtail** (~NZ$4) — - **N2K drop-tee** (~NZ$8, if not already a spare on the backbone). - **12V→5V buck** (~NZ$2) to power the ESP32 off the bus (respect the backbone LEN budget; ESP32 ≈ 2 LEN). - **Covers:** one modern N2K boat's own instruments — wind/heel/speed/depth — with zero installation skill. - **Note:** N2K is binary, so this firmware leans on the `NMEA2000` + `NMEA0183` Arduino libraries (Library Manager) — heavier than the self-contained 0183 sketch, but the boat-side is genuinely plug-in. ## 3b. Boat gateway, NMEA-2000 via Pi — ~NZ$40 (if you already run Signal K) The full-fat option if you want Signal K on the boat anyway (adds a proper data model, plugins, local logging). - **Raspberry Pi Zero 2 W** (~NZ$25) — - **USB↔CAN adapter** (~NZ$15) — Waveshare USB-CAN: - **N2K drop-tee + micro-C cable** (~NZ$15 if not already spare). - **Software:** Signal K + canboat + `signalk_telltale.py` (`provision.sh`). ## 4. Shore station, budget — ~NZ$75 ⭐ the club wedge One box in the clubhouse records the whole harbour's AIS keelboat fleet, automatically. - **Raspberry Pi Zero 2 W** (~NZ$25) — as above (Pi 3/4 for rock-solid unattended, +NZ$30). - **RTL-SDR dongle** (~NZ$15) — **RTL-SDR Blog V4** is the reliable choice: · AliExpress: - **Dedicated AIS/VHF antenna** (~NZ$25–50) — AliExpress "marine AIS antenna 162MHz": - **microSD (32GB) + 5V USB mains plug** (~NZ$15). - **Software:** AIS-catcher + Signal K + connector via `provision.sh shore`. - **Covers:** every AIS-equipped boat in view. Height + water-view of the antenna = range. ## 5. Shore station, solid — ~NZ$145 The set-and-forget clubhouse build. Same as #4 but bulletproof. - **Raspberry Pi 4 (2GB)** (~NZ$70) — - **RTL-SDR Blog V4** (~NZ$25) — as #4. - **Proper AIS antenna + coax** (~NZ$50) — outdoor, mast/roof mounted. - **Case + PSU + 64GB SD** (~NZ$25). - **Covers:** as #4, with headroom for years of unattended logging. ## 6. Boat AIS feeder, away races — ~NZ$95 A mobile shore-station-on-a-boat for offshore/coastal races where no clubhouse covers the course. That boat becomes the fleet's AIS feeder (and can push to AISHub for wider coverage). - **Raspberry Pi Zero 2 W** (~NZ$25) + **RTL-SDR Blog V4** (~NZ$25) — as #4. - **AIS/VHF antenna** (~NZ$25) — or an **active AIS splitter** (~NZ$150–250) to share the boat's transmitting VHF antenna. **Never a passive T-piece** — 25W VHF will fry the receiver. - **12V→5V buck converter, 3A, inline fuse** (~NZ$8) — off the same 12V as the VHF. AliExpress: - **microSD** (~NZ$12). - **Software:** `provision.sh boat … --sdr` — logs the fleet AND the boat's own instruments; always-log-to-SD means zero internet is fine. --- ### Antenna & power safety (applies to any SDR build) - A **cheap dedicated AIS antenna is always simpler** than sharing a transmitting VHF antenna. - To reuse a transmitting VHF antenna you **must** use an **active AIS splitter** — a passive splitter/T-piece routes the VHF's 25W into the receiver and destroys it. - On 12V (boat/VHF cabinet), use a **3A-rated buck converter with an inline ~1A fuse**. The Pi draws ~0.15A. ### Keeping your instruments to your own crew (boats race close!) Your wind/heel/target-speed is competitively sensitive, and 2.4GHz WiFi carries 50–100m+ over open water — boat-to-boat range at a start or mark. The relay to Telltale is encrypted and raw replays are login-gated, so the exposure is only the **local radio link**. Keep it private: - **Best: run the gateway in STA mode on your boat's own WPA2 WiFi.** UDP broadcast never leaves that network, and nobody joins without your password. - **AP mode uses a password UNIQUE to each box** (auto-derived from its chip ID, printed to serial on boot) — never a shared one, or a competitor with the same kit would know it. Give it only to your crew. - **Never put the gateway on an open or shared club/marina WiFi** — everyone on it sees the broadcast. - **BLE** is short-range (~10m) and unauthenticated — fine for your own phone; don't rely on it for privacy. ### What each kit does NOT do - A **boat gateway (#2/#3)** shares only that boat's own NMEA — not the wider AIS fleet. That's the shore station's job. - **AIS only catches transponder-equipped boats** (most keelboats; not dinghies) — pair any shore station with phones (#1) for full-fleet coverage.