Vehicle-Mounted Meshtastic Node Build

A vehicle-mounted mesh node extends your coverage as you drive and creates a mobile relay point that dramatically improves network coverage in areas you travel through regularly.

Design Goals for Vehicle Installations

• Always-on: Powered by the vehicle's 12V system; operational whenever the vehicle is running (or parked)
• External antenna: Roof or trunk-lid mounted magnetic base antenna for maximum range
• Phone integration: Bluetooth connection to your smartphone for messaging while driving
• GPS: Live position updates to the mesh from the vehicle's actual location

Hardware Bill of Materials

Antenna Mounting Options

The antenna location has the biggest impact on performance:

• Roof magnetic base — Best option. Full ground plane, maximum height. Requires routing cable through door jamb or sunroof. Use self-closing weatherstrip tape to seal around cable.
• Trunk lid lip mount — Good compromise. Lower than roof but cleaner install. Use trunk lid pass-through grommets.
• Dashboard mount (inside) — Acceptable for temporary use or urban environments where range is less critical. Glass attenuates RF by 5-10 dB.

Power Wiring

12V vehicle fuse panel
    → 2A fuse (in-line fuse holder)
    → Buck converter (12V to 5V/3A)
    → USB-C to T-Beam or other node

Recommended wiring gauge: 18 AWG minimum

Tap from a switched 12V source (ignition-switched) so the node powers off when the vehicle is off. Alternatively, use an always-on source if you want the node to continue operating as a parked relay — but ensure your vehicle battery won't be drained (add a low-voltage cutoff relay at ~11.8V).

Configuration for Mobile Use

# Device role for vehicle node:
meshtastic --set device.role ROUTER_CLIENT

# Position update interval for moving vehicle (60 seconds):
meshtastic --set position.position_broadcast_secs 60

# Ensure GPS is enabled for live position:
meshtastic --set position.gps_enabled true

# Keep BLE active for phone connection:
meshtastic --set power.wait_bluetooth_secs 0  # always on