This type of network can overcome the challenges of monitoring the environment and infrastructure in rural locations
The technical and financial barriers to entry of smart farming have decreased drastically over the past few years.
Smart farming refers to managing farms with modern information and communication technologies, which can provide efficiency gains for farmers.
A major component of a smart farm is monitoring the environment and infrastructure, but this can be challenging in rural locations and on farms that span large distances.
This is where LoRaWAN shines.
“Low power radio, that’s all LoRa means. When we talk about LoRaWAN, it’s a low-powered, wide-area network,” said Brian Tischler during a presentation at CropSphere in Saskatoon earlier this year.
“LoRaWAN uses a low-powered radio to make a network of these sensors all over an area as far as that little radio can reach. Generally it’s two to 20 kilometres apart, depending on the antenna and the antenna design.”
Tischler is an Alberta farmer who developed AgOpenGPS, which is capable of turning older tractors into robots that can perform complicated tasks autonomously, including seeding.
His presentation at CropSphere was designed to help people understand how to use internet of things (IoT) devices to turn their farms into a smart farm using LoRaWAN technology.
He said the possibilities are many in terms of what can be monitored on a farm.
For example, farmers can use a system to give a phone alert when a door is opened at the shop, when frost touches a crop, when soil temperature warms, when binned grain starts to produce CO2, which means it’s starting to heat, when a cow wanders outside its pasture, when a gate is opened a long distance away from the farm, when a field gets rain, or to measure soil moisture in a field.
There are many farmers who would rather pay a service provider to set up monitoring systems.
However, there are also farmers who want to set up and service their farm’s equipment by themselves, largely because they don’t like writing cheques for thousands of dollars or pay subscription fees if they don’t have to.
Do-it-yourself farmers will find it worth their time to pay attention to online communities to help them with what they need to know to remotely monitor their farms.
Tischler said there are few restrictions for bandwidths used in LoRaWAN networks, and they are free to use without a licence.
A basic sensor that connects to a network can be built for only a few dollars by ordering a sensor, a basic LoRaWAN board and a battery backup that will run for about a year.
Solder these three components together and farmers have the hardware component of a basic sensor, also referred to as a LoRa node.
The sensor will send packets of information through the board, which can also receive instructions and perform basic functions, such as turning a light or irrigation system on or off.
“What these things do is chirp information at a very slow rate, but it can go for miles and miles and miles in an extremely small device, and with really low power,” Tischler said.
He said the LoRa standard is a proprietary standard so it’s not open source, but the components are relatively inexpensive.
“All of those devices communicate on a standard, SDI-12. There is something called the EnviroDIY community, it’s a worldwide community and they’ve hacked all of that stuff to death. They have all the libraries, all the software, everything to talk to most sensors, and it’s all free to download,” Tischler said.
He said interest in weather information has driven the DIY LoRaWAN community.
Code for any of the specific sensors you want to add to your network can be copied from the EnviroDIY community (www.envirodiy.org).
Users then add the device ID or number on the board they want to include to the network to the code that was copied from EnviroDIY, and the LoRaWAN board is now programmed and ready to transmit sensory information.
The sensor connects to the LoRaWAN board that sends information over long distances to a component of the network called a gateway.
The gateway listens and collects all of the information that comes in from the sensors.
A LoRaWAN gateway can be bought set up already, or farmers can build their own using a Raspberry Pi — a small single board computer that is inexpensive and can be ordered with LoRaWAN, Bluetooth and wi-fi components already installed, and programmed to perform basic functions by using code available through online communities.
During his presentation Tischler showed a Raspberry Pi gateway he uses, which had eight inputs for sensors.
However, each sensor only sends information intermittently.
“So instead of only being able to listen to eight devices, if each device uses only one percent of the time, then you can listen to 800 devices,” Tischler said.
He said in many areas in the world, including Europe, there are already LoRaWAN gateway systems available so people wouldn’t have to bother to set up their own, but these networks are still uncommon in Canada.
The gateway then passes information through a home router to a network server, which acts like a bridge to the internet and functions somewhat like a traffic cop.
“That server could be in China, it could be on your desk in your house. It can be on the internet with parts and pieces all over the place; there is no real set pattern at this point,” Tischler said.
“The network server collects all the messages from the gateways. It figures out who is talking, and who is listening, who needs to listen and it temporarily stores the data.”
For a free network server, Tischler recommends The Things Network (TTN), which has more than 10,000 gateways on its system with millions of devices and more than 100,000 users.
To use node sensors on TTN, set up an account and input the device ID or number that was on the board used when programming the sensor node. It will automatically start receiving data.
Now that the sensor nodes are sending information to the LoRaWAN gateway, it is plugged into the router, which, in turn, sends the information to a network server (TTN), an application is needed that will go to the network server and harvest the data, as well as to send data or commands back to the nodes.
“This might seem complicated because there are a lot of steps. But really we have a little device sending information to a network server, now we’re just going to access the data,” Tischler said.
On TTN, users can easily set actions to be performed with their data.
For instance you can get an email when it gets below zero on one of your fields or a sensor that detects movement.
The information can be easily exported to Excel, or automatically sent to a C-sharp application that will make graphs in real time.
Farmers need to know that their investment of time and money will be worth it before jumping into a new technology because they don’t want to waste money on a new gadget they won’t use.
However, the LoRaWAN is an established and robust technology and more and more sensors are becoming available that are both capable and affordable.
For instance, Tischler said for $100 a farmer could set up a system to monitor 20 bins at a bin site located miles away from the farm because temperature sensors are very cheap.