In engineering, it’s common to deal with three competing factors: something can be produced well, cheaply, or fast. Networking has to make the same sort of tradeoffs, but parameters could be thought of as cost, transmission range, and transmission speed. For example, WiFi and Bluetooth connections are cheap (no monthly charges), with a large bandwidth for data transmission, yet range is quite limited. Cellular data can be transmitted worldwide with good speed, yet you’ll need to pay for the networked transmission.

What if you need to check a distributed array of sensors, or control devices on an intermittent basis where range is too far for WiFi? If you have tens, hundreds, or even thousands of these devices to control, data charges will soon get out of hand. As discussed in detail here, filling this need for a low-cost long range connection method is the LoRaWAN low power wide area network (LPWAN) specification, capable of operating at a 5 km to 10 km distance depending on conditions.

This type of network operates on the open radio spectrum, meaning that anyone is free to set up a LoRa network without data transmission fees. Cellular providers have also been developing LoRaWAN infrastructure, so if you do need this help to deploy your network initially, or if it grows beyond what your can easily maintain, this presents another interesting option.

The tradeoff to this type of network is that data transmission ranges—from .3 kbps to 50 kbps—are extremely slow by modern networking standards. For it’s intended purpose of low-bandwidth monitoring and control however, this would be entirely acceptable. Once data is transmitted from a remote sensor node to its gateway base station, data can then be sent to the cloud, allowing manipulation via a computer or any connected device device. This data can then be used to monitor or change parameters of this node. Because its now connected to the Internet, it can even interact with nodes on a different LoRa network with the same sort of gateway configuration.

LoRaWAN applications could include connected infrastructure, farming, power metering, or any other sensor-driven system. For the MakerPro (who is normally operating on a very limited budget) this opens up all kinds of connected possibilities. Perhaps you’d like to see when your mail arrives at a box just out of range of your traditional WiFi network or a smart dog collar that transmits GPS coordinates if he ever gets out would be possible, or you could even make an embedded bike tracking device for if it ever “runs off.” A rural setting would present even more hack possibilities, like the ability to remotely open and monitor gates or control agricultural equipment at different ends of a large piece of property.

Practically speaking, if you want to get started with this type of technology, several options are available. Dragino has a LoRa IoT development kit available, which includes a gateway as well as a pair of LoRaWAN shields. AllThingsTalk also offers a setup that’s worth checking out. With the possibility of tens of billions of connected devices by the 2020s—many of them linked via LPWANs—MakerPros have the ability to get an early start with this technology today.

Jeremy S. Cook is a freelance tech journalist and engineering consultant with over 10 years of factory automation experience. An avid maker and experimenter, you can see some of his exploits on the Jeremy Cook’s Projects YouTube Channel.

eletter-12-06-2017

eletter-12-05-2017