ISM Communications For Arduino

July 9, 2017 by Al Williams 14 Comments

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.

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Simple Range Testing For LoRa Modules

April 29, 2017 by Lewin Day 12 Comments

WiFi and Bluetooth have their use cases, but both have certain demands on things like battery life and authentication that make them unsuitable for a lot of low-power use cases. They’re also quite limited in range. There are other standards out there more suitable for low-power and wide area work, and thankfully, LoRa is one of them. Having created some LoRa pagers, [Moser] decided to head out and test their range.

Now, we’ve done range tests before. Often this involves sending one party out with a radio while the other hangs back at base. Cellphones serve as a communications link while the two parties go back and forth, endlessly asking “Is it working now? Hang on, I’ll take a few steps back — what about now?”

It’s a painful way to do a range test. [Moser]’s method is much simpler; set a cellphone to log GPS position, and have the pager attempt to send the same data back to the base station. Then, go out for a drive, and compare the two traces. This method doesn’t just report straight range, either — it can be used to find good and bad spots for radio reception. It’s great when you live in an area full of radio obstructions where simple distance isn’t the only thing affecting your link.

Build details on the pagers are available, and you can learn more about LoRa here. While you’re at it, check out the LoRa tag for more cool builds and hacks.

CES17: Arduino Unveils LoRa Modules For The Internet Of Things

January 6, 2017 by Brian Benchoff 34 Comments

WiFi and Bluetooth were never meant to be the radios used by a billion Internet of Things hats, umbrellas, irrigation systems, or any other device that makes a worldwide network of things interesting. The best radio for IoT is something lightweight which operates in the sub-Gigahertz range, doesn’t need a lot of bandwidth, and doesn’t suck down the power like WiFi. For the last few years, a new low-power wireless communication standard has been coming on the scene, and now this protocol — LoRa — will soon be available in an Arduino form factor.

The Primo, and NRF

It’s not LoRa, but the Arduino Primo line is based on the ESP8266 WiFi chip and a Nordic nRF52832 for Bluetooth. The Primo comes in the ever-familiar Arduino form factor, but it isn’t meant to be an ‘Internet of Things’ device. Instead, it’s a microcontroller for devices that need to be on the Internet.

Also on display at CES this year is the Primo Core which we first saw at BAMF back in May. It’s a board barely larger than a US quarter that has a few tricks up its sleeve. The Primo Core is built around the nRF52832, and adds humidity, temperature, 3-axis magnetometer and a 3-axis accelerometer to a square inch of fiberglass.

The Primo Core has a few mechanical tricks up its sleeve. Those castellated pins around the circumference can be soldered to the Alice Pad, a breakout board that adds a USB port and LiPo battery charger.

LoRa

Also on deck at the Arduino suite were two LoRa shields. In collobration with Semtech, Arduino will be releasing the pair of LoRa shields later this year. The first, the Node Shield, is about as simple as it can get — it’s simply a shield with a LoRa radio and a few connectors. The second, the Gateway Shield, does what it says on the tin: it’s designed to be a gateway from other Arduino devices (Ethernet or WiFi, for example) to a Node shield. The boards weren’t completely populated, but from what I could see, the Gateway shield is significantly more capable with support for a GPS chipset and antenna.

A partnership with Cayenne and MyDevices

Of course, the Internet of Things is worthless if you can’t manage it easily. Arduino has struck up a partnership with MyDevices to turn a bunch of low-bandwidth radio and serial connections into something easy to use. Already, we’ve seen a few builds and projects using MyDevices, but the demos I was shown were extremely easy to understand, even if there were far too many devices in the room.

All of this is great news if you’re working on the next great Internet of Things thing. The Primo Core is one of the smallest wireless microcontroller devices I’ve seen, and the addition of LoRa Arduino shields means we may actually see useful low-bandwidth networks in the very near future.

Mexican Highschoolers Launch 30 High Altitude Balloons

December 5, 2016 by Elliot Williams 15 Comments

No matter whether you call them “picosatellites” or “high altitude balloons” or “spaceblimps”, launching your own electronics package into the air, collecting some high-altitude photos and data, and then picking the thing back up is a lot of fun. It’s also educational and inspirational. We’re guessing that 264 students from 30 high schools in Aguascalientes Mexico have new background screens on their laptops today thanks to the CatSat program (translated here by robots, and there’s also a video to check out below).

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Building A LoRa PHY With SDR

November 18, 2016 by Brian Benchoff 6 Comments

The Internet of Things is terrible when it’s your toaster. The real fun happens when you have hundreds or thousands of sensors sending data back to a base station every day. That requires low power, and that means LPWAN, the Low Power Wide Area Network.

There are a lot of options for LPWAN, but few are a perfect fit. LoRa is one of the rare exceptions, offering years of operation on a single AA cell, and range measured in miles. Layers two and three of LoRa are available as public documentation, but until now layer one has been patented and proprietary. At the GNU Radio Conference, [Matt Knight] gave a talk on reverse engineering the LoRa PHY with a software defined radio. Now, LoRa is open to everyone, and anyone can decode the chirps transmitted from these tiny, low power devices.

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Hacking The Internet Of Things: Decoding LoRa

January 31, 2016 by Elliot Williams 20 Comments

Getting software-defined radio (SDR) tools into the hands of the community has been great for the development and decoding of previously-cryptic, if not encrypted, radio signals the world over. As soon as there’s a new protocol or modulation method, it’s in everyone’s sights. A lot of people have been working on LoRa, and [bertrik] at RevSpace in The Hague has done some work of his own, and put together an amazing summary of the state of the art.

LoRa is a new(ish) modulation scheme for low-power radios. It’s patented, so there’s some information about it available. But it’s also proprietary, meaning that you need a license to produce a radio that uses the encoding. In keeping with today’s buzzwords, LoRa is marketed as a wide area network for the internet of things. HopeRF makes a LoRa module that’s fairly affordable, and naturally [bertrik] has already written an Arduino library for using it.

So with a LoRa radio in hand, and a $15 RTL-SDR dongle connected to a laptop, [bertrik] got some captures, converted the FM-modulated chirps down to audio, and did a bunch of hand analysis. He confirmed that an existing plugins for sdrangelove did (mostly) what they should, and he wrote it all up, complete with a fantastic set of links.

There’s more work to be done, so if you’re interested in hacking on LoRa, or just having a look under the hood of this new modulation scheme, you’ve now got a great starting place.

The Future Of The Internet Of Things

November 16, 2014 by Brian Benchoff 81 Comments

When buying anything, you’re going to have a choice: good, fast, or cheap. Pick any two. A plumber will fix a drain good and fast, but it won’t be cheap. The skeezy guy you can call will fix a drain fast and cheap, but it won’t be good.

Such it is with radios. You can have long-range (good), high bandwidth (fast), or a low price (cheap). Pick any two. The Internet of Things demands a cheap, long-range radio module, but until now this really hasn’t existed. At Electronica last week, Microchip demoed their IoT solution, the LoRa. This module has a 15km (rural) or ~3km (heavy urban) range, works for a year on two AAA batteries, and is very cheap. Bandwidth? That’s crap, but you’re not streaming videos to your shoe.

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