Interesting low power, license-free radio tech suitable for a property-area or even much longer (article cites 10km - which is basically LOS) ranges.
Not sure what could be made of this, but a bonjour-based self-meshing comms network might be useful. Seems fairly robust to interference too.
Anybody toyed with this before?
@Canem uses this for some of his property network stuff - I expect he’ll have some insights!
I call it DEWS: driveway early warning system [a devlog] is LoRa based.
I got interested in LoRa because both point-to-point, mesh, and LoRaWAN stuff is very similar to APRS and some of its capabilities. I think LoRa is really cool in it’s up-and-coming state since no license is required. I think there are/will-be many more projects around to gather inspiration from folks who arn’t hams.
Not to mention the kilometers-per-watt is significantly higher. My comparison experiments have been pretty minimal and not at all rigorous, but the max output from a lora module is 20Dbm, or 0.1 watts. Similar performance near 144mhz APRS took .5 to 1 watt. So that opens up lots of possibilities with battery powered projects.
IIRC it claims down to -115Dbm sensitivity. I’ve tried it from about 100 meters away from the metal-sided shop building, and was still receiving at about -90Dbm. About -70Dbm if I opened the door.
LOS data on 1/10th a watt or less? Yes please!
LoRaWAN specifically I haven’t played with. I think you’d call that the complete network layer? it’s the standard for routing packets both in mesh configurations and the Lora/Internet bridges that exist in various forms. LoRa receivers moving data from the radio to a cloud server via MQTT, is one common example.
Like this: https://www.thethingsnetwork.org/
Personally (angst about cloud services aside) it’s more overhead than I’ve needed for my projects. I just talk to the radios directly, and handle packet creation/reception myself. Mostly it’s been arduino to arduino talking, but I also have one ‘gateway’ built to allow me to interface with the property-area-network stuff from any PC/phone in the house as well.
It’s in this picture, that I haven’t done a write up of yet. Above the light is a camera enclosure, into which I have stuffed a POE splitter, raspberry pi3, custom LoRa board, and noir camera.
Then with this project: RPi-Cam-Web-Interface - eLinux.org, I have buttons placed on the camera-viewing page that lets me open the gate, switch the lights, and so on. Receive button clicks on webpage, send commands out via LoRa.
I could go on! I’ve got several more half-done Lora projects around, and several more ideas for the future when I get those first ones done.
A $5 data radio the size of a postage stamp? This is the kind of technology I can get excited about!
I should get some of those to mess with. Just haven’t felt like screwing with microcontrollers lately.
I may do a driveway traffic detection system with ultrasonics - we can compare long term behavior!
Has anybody here heard of the gotenna mesh? goTenna Mesh | Buy Now
It’s a cool idea that started appearing in the HAM magazines a couple years ago. i was never able to find out what exactly the hardware inside is, but I’ve been thinking what a cool project it would be to try and build one with Lora and an esp32. Basically a tower-free short-range text-message network.
Using the esp32’s bluetooth means a smartphone could be the display and keyboard. Although since I know nothing about app development maybe it’s easier to make a full standalone terminal with tiny keyboard and display. Hmm… projects to dream about.
Update: I’m not the first to have this idea. yay!
Ok, time to go into my mantra: “No starting new projects until you finish the current ones… No starting new projects until you finish the current ones…”
If you go this route, one of the main issues is seeding enough boxes. May I suggest some small solar/battery/antenna boxes that look Very Official Indeed that can be attached to random power poles and buildings and hopefully stick around?
Ohh, I like that idea. I was thinking just devices carried by friends/groups and would work when they’re in range of each other, but that has me thinking.
Something like a big decal on the front:
Geological Survey Equipment. Please do not remove.
That, or stuff it into an old outdoor wireless access point enclosure. Nobody wants to interfere with the wi-fi 
I’ve been playing with the concept of wifi “standalone archive” systems for a while - think a local Wikipedia mirror, Gutenberg mirror, and some other helpful stuff along with a file drop zone.
May as well add mesh networking to them! 
Hmm, I like it. 2.4ghz/wifi data transfer with a UHF control link? Raspi Zero-W or maybe an ESP8266 for lower power consumption. There’s a lot of possibilities in that project.
I was thinking something in the line of a RasPi or RasPiZero, with appropriate stuff hung off it. The Zero would require a lot more external hardware than the Pi, which can be an AP with built in wifi, and has some full sized USB ports for bigger-antenna APs (I was thinking of an external antenna).
My tentative plan was to go with a SD card for the read only data (run the OS read only, main archive data is read only), and a F2FS filesystem on a USB drive for the read-write storage. That way, it’s less likely to zap the main SD card with write traffic - and random power cuts aren’t a big deal, data-integrity-wise. Toss an Arduino on to control power to the main system, use a low temperature tolerant chemistry (or simply refuse to charge if cold), and you’d have a year round data store.