Flipper Zero GPS module wiring for wardriving GPIO fix

Flipper Zero GPS Wardriving Setup: The GPIO 15/16 vs 13/14 UART Fix

PINGEQUA Lab · Troubleshooting · 6 min read · Updated 2026-07-15

Your Flipper's GPS app says "No fix" and you've been staring at the sky. Ninety percent of the time it's not the sky, the antenna, or the module — it's which two pins the GPS is talking on.

Quick answerOn a Flipper Zero, the ESP32 Wi-Fi module lives on the USART pins, GPIO 13/14. A GPS receiver cannot share that UART, so it has to go on the second UART — LPUART, GPIO 15/16. If your GPS app shows "No fix," the NMEA channel is almost always still pointed at 13/14, where the ESP32 already sits. Fix it in Momentum → Protocols → GPIO Pins, set NMEA GPS UART = "Extra 15,16", and the fix appears. Boards like Scout Lite hard-wire the GPS to avoid this entirely.

Why the conflict exists

The Flipper Zero exposes two serial (UART) interfaces on its GPIO header, and they are on different pins:

UART Pins Typically used by
USART GPIO 13 (TX) / 14 (RX) ESP32 Wi-Fi module (Marauder)
LPUART GPIO 15 (TX) / 16 (RX) GPS / NMEA receiver

A single UART can only talk to one device. If you plug in a Wi-Fi board and a GPS and leave both pointed at USART 13/14, they collide — and the device the firmware isn't listening for (usually the GPS) reports nothing. The Flipper gives you the second UART, LPUART on 15/16, precisely so both can run at once. The job is just telling the firmware which is which.

This is a firmware setting, not a hardware fault. A GPS reporting "No fix" indoors after 30 seconds is normal. A GPS reporting "No fix" outdoors after several minutes, with a clear sky, is almost always the UART mapping — not a dead module.

The fix, step by step (Momentum)

Momentum (and Xtreme) firmware exposes the pin mapping in the UI. Stock firmware pins the NMEA UART to 13/14 by default, which is why the native GPS app fights the ESP32 there.

  1. On the Flipper, open Momentum (the main settings app, labelled MNTM).
  2. Go to Protocols → GPIO Pins.
  3. Find NMEA GPS UART. Press right to cycle it to "Extra 15,16".
  4. Confirm the ESP32 / UART channel stays on 13,14 so the two don't overlap.
  5. Back out to save, then open the GPS app. Outdoors, wait for a fix — a cold start is a minute or two.

For wardriving specifically, note an important detail: the wardrive log is written by the ESP32 Marauder app, which reads the GPS on its own — so Marauder wardriving can log location even if the Flipper's native GPS app isn't mapped. The 15/16 mapping is what you need for the Flipper's own GPS app to show a fix alongside it. Our full wardriving guide covers the whole loop.

Still no fix after remapping?

Symptom Likely cause Try
No fix indoors No sky view Go outside; GPS needs line of sight to satellites
No fix outdoors, minutes UART still on 13/14 Recheck NMEA = "Extra 15,16"
Garbled / no data Baud-rate mismatch Confirm module baud (commonly 9600) matches firmware
Works then drops Loose seating on header Reseat the module firmly on the GPIO header

The zero-config route

The whole conflict is a wiring-and-config problem that only exists when the GPS and ESP32 are separate parts you connect yourself. On an integrated board like Scout Lite, the GPS is hard-wired to the ESP32-C5 and its NMEA also fans out to the Flipper's GPIO 15/16 — so Marauder logs location the moment you power on, and the native GPS app has its pins already. If you prefer to build your own rig, a discrete GPS module works fine; you just own the pin mapping above.

Skip the pin wrangling

Scout Lite hard-wires the L86-M33 GPS to the ESP32-C5 and pre-flashes Marauder — power on, start Wardrive, log location. No 13/14 vs 15/16 to fight.

Get Scout Lite Discrete GPS module

FAQ

Which pins does the Flipper GPS use — 13/14 or 15/16?
The GPS/NMEA UART should be on GPIO 15/16 (LPUART). GPIO 13/14 (USART) is where the ESP32 Wi-Fi module sits, so the two can't share it. Set NMEA to "Extra 15,16" in Momentum → Protocols → GPIO Pins.
Does wardriving need the 15/16 mapping?
Not strictly — the ESP32 Marauder app reads GPS itself and can log location for wardriving regardless. The 15/16 mapping is what lets the Flipper's own native GPS app show a fix at the same time.
Does stock Flipper firmware support this?
Stock firmware pins the NMEA UART to 13/14 by default, which collides with the ESP32. Momentum (or Xtreme) lets you move NMEA to 15/16 in the GPIO Pins menu, which is why it's the recommended firmware for GPS + Wi-Fi together.
My module still shows no data after remapping.
Check baud rate (many GPS modules default to 9600) and reseat the module on the header. Confirm you're actually outdoors with sky view — GPS won't fix reliably indoors.
Can I avoid this entirely?
Yes — an integrated board hard-wires the GPS to the ESP32 and pre-maps the Flipper pins, so there's nothing to configure. That's the design of boards like Scout Lite.

Sources: Momentum Firmware — Protocols / GPIO wiki (momentum-fw.dev/wiki/Protocols/GPIO and github.com/Next-Flip/Momentum-Firmware/wiki/GPIO, 2026); justcallmekoko/ESP32Marauder Wardrive wiki (github.com, 2026). Pin roles per Momentum documentation; Scout Lite wiring per PINGEQUA listing.

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