Hardware

Find a flock where the network does not reach

A dehesa in Extremadura, without stable mobile coverage.

The problem

Commercial trackers depend on a cellular network and a monthly fee. There is no stable network here, and no fee that would fix that.

The solution

A private LoRa mesh on 868 MHz. Each collar reports every 30 minutes — a 5-minute floor under movement — to a gateway. A Raspberry Pi bridge, with a 4G router, uploads positions to a self-owned server. The app draws the flock and alerts if one crosses a virtual gate.

A flock moving along a dehesa track
An Extremadura dehesa backlit at dusk

Architecture

CollarLoRa 868GatewayPi + 4GApp

The app

A custom iOS app for the shepherd. The farm is parameterized with its perimeter and its gates; the system alerts if a collar leaves the farm through a gate (exit alert).

Recreated map view: the flock and the farm perimeter with its gates
Map — The flock in real time. Recreated view.
App Status screen: last packet, signal and battery per collar
Status — Last packet, signal (RSSI/SNR) and battery per collar.
Recreated route view: a track coloured by signal quality
Routes — Historical track with signal quality per segment. Recreated view.

Decisions

D-cellESTIMATE

LiSOCl₂ ER34615 cell. ~22 months projected autonomy.

IP65VERIFIED

Sealed ABS box with a printed PETG cradle. Field, rain, oak.

FPC antennaVERIFIED

Radio inside the box. No external mast to rip off.

No repeaterVERIFIED

Field day, 300 packets, direct link. Covers.

Hardware

Three test boards, for range checks and measurements. Not the final ones.

Status

  • Backend in production
  • First collars assembled
  • System operational