If you want to wirelessly communicate between devices, WiFi and Bluetooth are obvious choices. But there’s also the ISM (industrial, scientific, and medical) band that you use. There are inexpensive modules like the SX1278 that can handle this for you using LoRa modulation, but they haven’t been handy to use with an Arduino. [Jan] noticed the same thing and set out to build a shield that allowed an Arduino to communicate using LoRa. You can find the design data on GitHub. [Jan] calls it the LoRenz shield.
According to [Jan], the boards cost about $20 to $30 each to make, and most of that cost was in having PC boards shipped. LoRa lets you trade data rate for bandwidth, but typical data rates are fairly modest. As for range, that depends on a lot of factors, too, but we’ve seen ranges quoted in terms of miles.
Depending on where you live, there may be legal restrictions on how you use a radio like the SX1278. You should understand your local laws before you buy into using the ISM bands. We aren’t sure it would be wise, but the board can coexist with three other similar shields. So you could get 4 radios going on one Arduino if you had too and could manage the power, RF, and other issues involved. The breakout board the module uses has an antenna connector, so depending on your local laws, you could get a good bit of range out of one of these.
[Jan] promises a post on the library that makes it all work shortly, but you can find the code on GitHub now. If you look at the code in the examples directory, it seems pretty easy. You’d have to sling some software, but the SX1278 can support other modes in addition to LoRA including FSK and other data modulation techniques.
We’ve seen other LoRa shields, but not many. If you are interested in other wireless technologies, we’ve talked about them quite a bit. If you want a basic introduction to LoRa, [Andreas Spiess’] video below is a good place to start.
Eep, the first link in the post gives a 404.
Looks like tutorial was pulled from that site for some reason. *shrug*
That is strange. If you search the site for Lorenz it also gives a 404 like it is still in the search index but has been removed. As [q2dg] says, thought, the GitHub link is still good.
It’s back!
At least GitHub’s link is on…
Has anyone tried the $14 LoRa32u4 boards? (Atmega32u4 + LoRA RA02 (uses SX1278))
Go them working last week, but not much more. They are clones of Adafruit Feather LoRa with only one pin changed. There must be some errors in traces which resulted in some nice soldering magic.
Bluetooth and Wifi use ISM bands too.
You technically need an amateur radio licence to operate any non-type approved transmitter. Power level doesn’t matter. You also need to follow the rules about identifying and no encryption.
In region 2 (North America) 433Mhz isn’t an ISM band. If your making a product that will be type approved it will have to use 915Mhz in Region 2.
All that said they don’t drive around in van looking for people breaking the law. They only respond to complaints of interference. So as long as you keep the power down and stick to ISM bands your likely to stay out of trouble. Also if your doing encrypted communication that looks legal, no one can tell your not using type approved gear.
+A That’s exactly what I came to the post to say — both BT and Wifi are in ISM. But you beat me to it, thanks!
In Australia there is a general low interference potential devices class license that covers most of these Lora modules.
The US 915MHz band is the equivalent to the EU 868MHz band. There is GSM service in these bands in the other region. The US equivalent to the EU 433MHz band is the 315MHz band.
Aren’t the used transmitters type approved? I can buy the dragino shield for the arduino/raspberry and the arduino fether in my country from several shops (I live in west europe).
So the seller wouldn’t be allowed to sell me the things, if it were illegal to opperate. Because in my country it is illegal to sell ham equipment to people with no ham licence, so that would be something similar.
Hello everyone!
Sorry to hear that the article was unavailable for a while, apparently there were some issues with the site update. The first article is available once again and the second one should be published soon.
Did you forget about Sigfox?
In Australia- http://www.thinxtra.com/xkit
That’s an Arduino shield bundled with included Arduino clone board and Sigfox platinum connectivity. All that is needed to play with sigfox!
Arduino to cloud, no basestations needed as long as you are in a coverage area.