Summary

Company: Nebra LTD.
Tasks: Electrical Design, PCB Design, Embedded Software Development, Python Software Development, Production Management, Quality Control, Hand Assembly of Prototypes, Certification Management, Documentation & Testing.
Date: First produced January 2021
Status: In Production
FInd out more at: https://helium.nebra.com/indoor-hotspot/overview

Overview

The Nebra Indoor Helium Hotspot, designed as a more user friendly variant of the Nebra Hotspot Range.

One of the biggest projects I've worked on at time of writing, the Nebra Indoor Hotspot is designed for use with the Helium Network and rewards people in HNT for providing LoRaWAN coverage on the Helium Network.

Hardware

The hardware is a more simplified design than the outdoor unit to optimise it more for mass production along with being in a more compact form factor.

Designed to use the Compute Module 3 Daughterboard, the motherboard contains circuitry to regulate the 12v down into the respective voltage rails for main components, a USB hub and headers to provide spaces for Bluetooth & Wi-Fi adaptors and built in networking with finally space for the LoRa Radio Module.

The Indoor Hotspot comes as a completed product which has also undergone CE & FCC certification and is designed to be plug and play.

Software

The software has been a significant part of making this project what it is.

As the main software developer for this project I was responsible for getting all the required software for the unit to operate as intended, along with writing creating our own software to improve user experience.

To provide OTA updates we decided to use Balena & Balena OS as our base, this provided us with a stable and reliable base for our software to run on top and ensures we have a robust system to keep the units in the wild up to date.

The software is then comprised of multiple docker containers running the software responsible to get the unit to work including:

  • Configuration Tool - Communicates over BTLE to the Helium App that allows users to setup their hotspots with ease. This was a full re-implementation to add in our own customisation and make it compatible with the Linux Network Manager.
  • Diagnostics Tool - Provides a basic webpage that users can access on their local network to ensure the hotspot is operating as intended.
  • Packet Forwarder - Configures on boot, then runs the software required to operate the radio module.

The unit also runs a tool to configure port forwarding on boot using UPNP, a tool that runs on first setup to program chips during production.

Finally it runs the Helium Miner itself, this is provided to us as a ready made container by Helium and has some tweaks to help speed up initial setup.

All of the docker containers and software are open source, and can be found at https://github.com/nebraltd/helium-miner-software

Production

For this product I was also responsible for organising some crucial production stages.

Being a fully finished product, I created step by step assembly guides for the assembly partners to use. Rigs used to test and store to a database crucial information such as serial numbers with finally automating printing labels for each unit with their respective serial numbers, model numbers and certification logos for the regions the hardware variation would be sold in.