Overview

In this guide, we'll be connecting a sensor to two Feathers and pairing them with a gateway to bring all the data collected into the cloud. We're going to build our own network to send data from devices to a router. The router will then decode the data packets and route them to Adafruit IO or The Things Network. 

Here's a network map (also known as a network topology) of the connections between the nodes/gateways/protocols of our network.

We will show how to make two different types of Feather to Raspberry Pi gateway networks - plain LoRa to adafruit.io and LoRaWAN for sending to The Things Network

Selecting a Transport

Devices need a way to communicate their data - the first step in building a network is selecting a mode of transport. As humans, we talk to each other in our native language(s). Electronic devices can also talk to each other, and there's a plethora of ways for them to communicate (for more information on transports, check out our All the Internet of Things - Part 1, which explains more about selecting a transport for your project)

LoRa to adafruit.io

In the first part of this guide, we're going to employ an Internet-of-Things transport protocol called LoRa to have our Feathers communicate with the Raspberry Pi Gateway. While we could use WiFi/BTLE/Cellular, we're not sending a large amount of data (a few bytes). We also do not need to send this data quickly, our sensors will transmit their data to the router every 15 minutes or so. 

By sacrificing transmit speed and the amount of data which we're able to send, LoRa radios can transmit much farther than Bluetooth Low-Energy and WiFi with lower power utilization.

LoRaWAN to The Things Network

The second part of this guide uses LoRaWANLoRaWAN is a Low Power Wide Area Network (LPWAN) specification which allows connection of LoRa devices to the internet. LoRaWAN differs from LoRa by the inclusion of a physical layer.

Selecting a Device

To begin building a sensor network, we'll specify what we want the sensor device to do:

  • Read a sensor
  • Send data over LoRa (it'll need a LoRa radio)
  • Connect to a LiPo battery (wireless operation!)
  • Run CircuitPython

A board which meets all of these specifications is the Feather M0 with RFM95 LoRa Radio. This microcontroller runs CircuitPython, has a built-in LoRa radio, and a connector for LiPo batteries. 

Adafruit Feather M0 with RFM95 LoRa Radio - 900MHz

PRODUCT ID: 3178
This is the Adafruit Feather M0 RFM95 LoRa Radio (900MHz). We call these RadioFruits, our take on an microcontroller with a...
$34.95
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Next up, we'll need a sensor to gather and send data. The BME280 is a fantastic environmental sensor - it can read a location's temperature, barometric pressure, and humidity. 

Adafruit BME280 I2C or SPI Temperature Humidity Pressure Sensor

PRODUCT ID: 2652
Bosch has stepped up their game with their new BME280 sensor, an environmental sensor with temperature, barometric pressure and humidity! This sensor is great for all sorts...
$19.95
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Selecting a Router/Gateway

We're going to use the LoRa Radio Bonnet and a Raspberry Pi Zero W to act as a gateway - converting incoming packets (from the feathers) to readable values. After it converts this data, it'll forward it to either Adafruit IO or The Things Network.

Adafruit LoRa Radio Bonnet with OLED - RFM95W @ 915MHz

PRODUCT ID: 4074
The latest Raspberry Pi computers come with WiFi and Bluetooth, and now you can add even more radio options with the Adafruit Radio Bonnets! Upgrade your Raspberry Pi with a LoRa /...
$32.50
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1 x Rasperry Pi Zero
Raspberry Pi Zero with Headers

Parts

You'll want to grab the following parts for this project:

2 x FeatherWing Proto
FeatherWing Proto - Prototyping Add-on For All Feather Boards
1 x 8GB SD Card with NOOBS
8 GB MicroSD Card with full PIXEL desktop NOOBS - v2.8
1 x MicroUSB Power Supply
5V 2.5A Switching Power Supply with 20AWG MicroUSB Cable
1 x MicroUSB Cable
USB cable - USB A to Micro-B - 3 foot long
This guide was first published on Feb 05, 2019. It was last updated on Feb 05, 2019. This page (Overview) was last updated on Feb 11, 2019.