Overview

LoRaWAN is similar to a cellular network, our suggested provider is The Things Network, a community-driven initiative with a large amount of public gateways to connect to (check out the map of publicly listed gateways here). 

We're going to build a gateway (highlighted in red in the diagram below) to pass data from your LoRaWAN device to the internet. 

raspberry_pi_what-is-lorawan_edited.png
LoRaWAN Network Topology (via https://lora-alliance.org/sites/default/files/2018-04/what-is-lorawan.pdf)

What is a LoRaWAN Gateway?

If have a Pi (or Feather)  LoRaWAN device set up, you'll likely want to immediately start working with LoRaWAN. Our suggested network is The Things Network, a community-driven initiative with a large amount of public gateways to connect to (check out the map of publicly listed gateways here). 

Gateways form a bridge a LoRaWAN device and the Network, receiving the device's data and forwarding them an application.

If you don't have a gateway near you, it's possible you could face a dead-end. While multi-channel gateways exist (we stock the official The Things Gateway), they're often expensive - placing a cost barrier on entering the network (as a hobbyist/hacker/experimenter). 

About Single Channel Gateways

Single channel gateways are NOT LoRaWAN-compliant or officially supported by The Things Network.

Single channel gateways (like the one we'll be building) are a LoRa device which forwards data to a network. They're great for getting into LoRaWAN without purchasing a more expensive "full gateway" (like The Things Network Gateway we stock).

However...

Single-channel gateways are not LoRaWAN compliant and are not currently supported by The Things Network (due to poor coverage, among other reasons). For more information about the debate about single channel gateways, check out The Things Network forum.

Parts

The LoRa Radio Bonnet is recommended for this guide - you not only get a radio module, but also a 128x32 OLED display for status messages and three buttons you can use for creating a custom user interface or sending test messages. 

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
IN STOCK

There's also a 433MHz version which uses the amateur or license-free ISM band (ITU "Europe" license-free ISM or ITU "American" amateur with limitations).

Adafruit LoRa Radio Bonnet RFM96W @ 433MHz

PRODUCT ID: 4075
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 /...
OUT OF STOCK

For a less-permanent gateway build, you can build a gateway using a RFM95W LoRa radio breakout and an OLED display, along with a few buttons.

Adafruit RFM95W LoRa Radio Transceiver Breakout - 868 or 915 MHz

PRODUCT ID: 3072
"You see, wire telegraph is a kind of a very, very long cat.  You pull his tail in New York and his head is meowing in Los Angeles.  Do you understand this? And...
$19.95
IN STOCK

There's also a 433MHz version which uses the amateur or license-free ISM band (ITU "Europe" license-free ISM or ITU "American" amateur with limitations).

1 x Adafruit RFM96W 433MHz
RFM96W LoRa Radio Transceiver Breakout - 433 MHz

Raspberry Pi Zero W

PRODUCT ID: 3400
If you didn't think that the Raspberry Pi Zero could possibly get any better, then boy do we have a pleasant surprise for you! The new Raspberry Pi Zero W...
$10.00
IN STOCK

Raspberry Pi 3 - Model B+ - 1.4GHz Cortex-A53 with 1GB RAM

PRODUCT ID: 3775
The Raspberry Pi 3 Model B is the most popular Raspberry Pi computer made, and the Pi Foundation knows you can always make a good thing better! And what could make the Pi 3...
$35.00
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You'll also want to pick up the following parts from the Adafruit Shop if you do not have them already:

1 x Pi T-Cobbler Plus
GPIO Breakout - Pi A+, B+, Pi 2, Pi 3, Zero
1 x I2C OLED Display
Monochrome 128x32 I2C OLED graphic display
1 x Breadboarding Wire Bundle
75 flexible stranded core wires with stiff ends.
1 x Tactile Buttons
Tactile Switch Buttons (12mm square, 6mm tall) x 10 pack
1 x Breadboard
Full Sized Breadboard
1 x uFL Antenna
uFL SMT Antenna Connector
1 x Raspberry Pi Power Supply
5V 2.5A Switching Power Supply with 20AWG MicroUSB Cable
1 x 8GB SD Card with OS
8GB SD Card w/ Raspbian Stretch Lite

Pi Wiring

Antenna Wiring

You can use a wire-based antenna, but this 1/2 wave whip antenna we stock works with the LoRa radios we have and extends the range of the gateway.

900Mhz Antenna Kit - For LoPy, LoRa, etc

PRODUCT ID: 3340
This LoRa Antenna Kit is meant for use with the LoPy LoRa, WiFi and BLE board or the SiPy Sigfox,...
$12.75
IN STOCK

If you have a LoRa Radio Bonnet, you can connect the antenna directly to the uFL antenna on the bonnet.

Pi Wiring

If you're using an Adafruit LoRa Radio Bonnet, you do not need to wire anything - proceed to setting up the Raspberry Pi as a gateway.

If you're using a breadboard, follow the wiring below

Wiring the Push-Buttons

We'll start by wiring three buttons. These will the physical interface between the Raspberry Pi and the Radio - we'll want to control the radio by pressing some buttons.

Make the following connections between the Pi and the three push-buttons:

  • Pi GPIO #5 to Button A (orange wire)
  • Pi GPIO #6 to Button B (blue wire)
  • Pi GPIO #12 to Button C  (green wire)
  • Pi 3.3V to Power Rail (red wire)
  • Pi GND to Ground Rail (black wire)

Wiring the OLED

  • Display GND to Raspberry Pi GND (black wire)
  • Display Vin to Raspberry Pi 3.3V (red wire)
  • Display SCL to Raspberry Pi SCL (green wire)
  • Display SDA to Raspberry Pi SDA (yellow wire)

Wiring the RFM Radio Module

Make the following connections between the Raspberry Pi and the RFM Radio Module:

  • Vin to Raspberry Pi 3.3V
  • GND to Raspberry Pi Ground
  • RFM G0 to Raspberry Pi GPIO #5
  • RFM RST to Raspberry Pi GPIO #25
  • RFM CLK to Raspberry Pi SCK
  • RFM MISO to Raspberry Pi MISO
  • RFM MOSI to Raspberry Pi MOSI
  • RFM CS to Raspberry Pi CE1

Next, let's move on to installing the necessary files for this project.

Things Network Raspberry Pi Setup

This guide assumes that you've gotten your Raspberry Pi up and running, and have CircuitPython installed.

Installing CircuitPython Libraries

We're running CircuitPython on the Raspberry Pi, installing the libraries for radio communication is simple.

To install the library for the display, enter the following into the terminal:

pip install adafruit-circuitpython-ssd1306

You'll also need to install the framebuf module in order to write to the display. 

sudo pip3 install adafruit-circuitpython-framebuf

To install the library for the RFM9x Module, enter the following into the terminal:

sudo pip3 install adafruit-circuitpython-rfm9x

Testing the Setup

There have been a lot of steps so far - let's verify that everything is wired up and all the libraries are installed properly before moving on to sending and receiving data. 

The following code is for checking if the RFM9x radio is set up for transmitting and receiving. Save the code on your Pi as rfm9x_check.py.

"""
Wiring Check, Pi Radio w/RFM9x

Learn Guide: https://learn.adafruit.com/lora-and-lorawan-for-raspberry-pi
Author: Brent Rubell for Adafruit Industries
"""
import time
import busio
from digitalio import DigitalInOut, Direction, Pull
import board
# Import the SSD1306 module.
import adafruit_ssd1306
# Import the RFM9x radio module.
import adafruit_rfm9x

# Button A
btnA = DigitalInOut(board.D5)
btnA.direction = Direction.INPUT
btnA.pull = Pull.UP

# Button B
btnB = DigitalInOut(board.D6)
btnB.direction = Direction.INPUT
btnB.pull = Pull.UP

# Button C
btnC = DigitalInOut(board.D12)
btnC.direction = Direction.INPUT
btnC.pull = Pull.UP

# Create the I2C interface.
i2c = busio.I2C(board.SCL, board.SDA)

# 128x32 OLED Display
display = adafruit_ssd1306.SSD1306_I2C(128, 32, i2c, addr=0x3c)
# Clear the display.
display.fill(0)
display.show()
width = display.width
height = display.height

# Configure RFM9x LoRa Radio
CS = DigitalInOut(board.CE1)
RESET = DigitalInOut(board.D25)
spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)

while True:
    # Clear the image
    display.fill(0)

    # Attempt to set up the RFM9x Module
    try:
        rfm9x = adafruit_rfm9x.RFM9x(spi, CS, RESET, 915.0)
        display.text('RFM9x: Detected', 0, 0, 1)
    except RuntimeError:
        # Thrown on version mismatch
        display.text('RFM9x: ERROR', 0, 0, 1)

    # Check buttons
    if not btnA.value:
        # Button A Pressed
        display.text('Ada', width-85, height-7, 1)
        display.show()
        time.sleep(0.1)
    if not btnB.value:
        # Button B Pressed
        display.text('Fruit', width-75, height-7, 1)
        display.show()
        time.sleep(0.1)
    if not btnC.value:
        # Button C Pressed
        display.text('Radio', width-65, height-7, 1)
        display.show()
        time.sleep(0.1)

    display.show()
    time.sleep(0.1)

To use the code, enter the following in your terminal:

python3 rfm9x_check.py

You'll also want to download the font file, font5x8.bin, and copy it into the same directory as the script:

Then, let's check the setup:

If the RFM9x is detected, the OLED will display Detected! 

 

You can test  the buttons by pressing them and watching the display for changes.

If the wiring of the radio module is incorrect - the display will show ERROR. Check over your wiring on the Wiring Page and re-run the test. You may also need to ensure the correct CircuitPython library is installed for the module. 

 

If the OLED does not turn on - first check that it is wired correctly. Then, make sure you enabled I2C from raspi-config and installed the required libraries (adafruit-circuitpython-framebufand adafruit-circuitpython-ssd1306).

Install the Single Channel Pi Gateway

First, install wiringpi by first cloning the source

git clone git://git.drogon.net/wiringPi

Navigate into the directory

cd ~/wiringPi

Build WiringPi:

./build

 

Then, clone the packet forwarder repository 

git clone https://github.com/adafruit/single_chan_pkt_fwd.git

Navigate into the packet forwarder directory

cd single_chan_pkt_fwd/

and compile the code for the gateway

sudo make all

You'll also want to download the font file, font5x8.bin, and copy it into the same directory as the script:

Gateway Usage

From within the single_chan_pkt_fwd/ folder, run the Python program by entering the following into the terminal:

python3 lorawan_gateway.py

The display should show the Gateway EUI. Keep this screen open, we'll need it for the next step.

Configuring The Things Network

Registering a Gateway with The Things Network

Before a Gateway can be used with The Things Network (TTN), it needs to be registered.

First, register an account with TTN

Once logged in, navigate to the The Things Network Console. This page is where you can register applications and add new devices or gateways.

Click Gateways 

Click register gateway

Tick the I'm using the legacy packet forwarder checkbox.

Then, enter the Gateway EUI displayed on the gateway.

Fill out a description of what the gateway is.

 

Set the frequency plan to your region's frequency, we set ours to United States

 

Set the Router to the location closest to you

  • Adafruit is located in New York City, so I set the router to ttn-router-us-west. 

Click Register Gateway. TTN will register the gateway and redirect you to the Gateway Overview page.

The Things Network does not list Single Channel gateways on their map - these gateways are not great at handling multiple devices or accurately receiving a packets every time they're sent by a device. However, they're great for hacking on, experimenting, and using in a staging/lab setup. 

We'll want to set the Gateway Privacy to Private and set the location to Unlisted

From the Gateway Overview page, click Edit Info.

On the Privacy Page, untick all of the options and click Save Settings.

Before starting up the gateway, we'll optionally set the gateway information.

 

From the Gateway Overview page, click Edit Info 

 

For brand, select Single-Channel DIY Gateway

 

For model, type Raspberry Pi

It's time to test! Run the Python program by entering the following into the terminal:

python3 lorawan_gateway.py

and press the middle button to launch the gateway.

You should see the Status of the gateway on your console switch from from Not Connected to Connected. If you've had previously connected the gateway: the Last Seen label should update to Now

Our gateway is now listening for new packets, it'll refresh whenever it's received a new packet.

Next, we're going to set up a device to send data to the gateway.

Troubleshooting your Gateway

My gateway doesn't appear as "connected" in the console.

Double check the configuration steps on this page. Make sure the Pi is connected to the internet and that the Gateway EUI matches the Gateway EUI displayed on the Pi's display.  

Device Setup

Next, you'll need a LoRaWAN device to send data to the single-channel gateway. 

Don't have a LoRaWAN device?

We have a few options for getting one up and running - with support for CircuitPython and Arduino.

Building a CircuitPython LoRaWAN Device

If you'd like to use CircuitPython to send data to the gateway, we have two guides which use CircuitPython and the CircuitPython_TinyLoRa library.

This guide sets up weather-logging LoRaWAN device with an Adafruit Feather.

 

It works with any of the Feather Family boards which run CircuitPython and a RFM9x breakout, Feather M0 LoRa or a Radio FeatherWing. 

Building an Arduino CircuitPython Device

This guide uses an Adafruit Feather M0 LoRa and a DHT22 temperature sensor to capture and send data to The Things Network using either the MCCI LoRaWAN LMIC Library or the Adafruit TinyLora Library.

Now that we have a LoRaWAN Device, let's use it to send data to to our gateway.

Gateway Usage

Configuration between Device and Gateway

Before we broadcast to the single-channel radio, there are some things to keep in mind:

Since this gateway only listens on one channel - frequency and spread factor should be the same between both the gateway and the device. This means that if you're sending data over 904.1MHz (channel 1 in the US) with spread factor of 7, the gateway should be listening  for transmissions on 904.1MHz with a spread factor of 7.

From the gateway, you can check and/or modify the gateway's configuration within global_conf.json under freq and spread_factor.

You'll want to modify your code to send over a single-channel (frequency). By default, TinyLoRa sends with a spread factor of 7.

Gateway Usage

Run the Python program by entering the following into the terminal:

python3 lorawan_gateway.py

Press the first button to display statistics about the Pi, such as its IP, CPU load, and available memory.

Press the third button to display the name of the gateway along with the frequency, spreading factor, and The Things Network router.

Press the second button to launch the gateway. It'll display the current status (if a packet is received or not) and update the timestamp every minute.

When a LoRa Packet is received by the gateway, the terminal will display that a packet has been received, and it'll print out useful data coming from the packet :

Download: file
incoming pkt...
{"rxpk":[{"tmst":4067850409,"freq":905.1,"chan":0,"rfch":0,"stat":1,"modu":"LORA","datr":"SF7BW125","codr":"4/5","rssi":-35,"lsnr":10.0,"size":24,"data":"QLERAiYAKAABE0NCX+3lkSnK09WVlk8N"}]}

The display will also refresh to display that a packet has been received. In this example, we're sending data from a RFM9x FeatherWing to the Gateway:

We can't read the incoming data since it's encrypted. After all, device data shouldn't be read-able by a gateway operator. We'll need to check our device on The Things Network Console to read the decrypted data.

From The Things Network Console, navigate to the data tab for the device. You should see a packet pass through this page when a new packet is received.

 

 

Click on the packet to display the packet's payload

 

 

Scrolling down on the packet's information will show the gateways used to communicate (one device can communicate to more than one gateway) and the packet's information (metadata) .

We've received data, but what about making it readable by humans - we have instructions about using the Things Network's payload decoder here.

This guide was first published on Jan 17, 2019. It was last updated on Jan 17, 2019.