Giving Your Pets A Digital Squeak

A pet tracker has a particularly grueling set of requirements: small, light, rugged, incredibly long battery life, safe for the pet, and cheap. [Mihai Cuciuc] was looking at the options and wasn’t thrilled with any of them. So as any hacker would, he rolled his own, dubbed Squeak.

It uses an RN2483 module as it is a LoRAWAN module with publically available firmware from Microchip itself. This means [Mihai] could add his code and keep the modem code without having to reverse engineer everything or add a second microcontroller. In addition to the modem, there’s a GPS unit connected via UART. The clever part is the dual voltage regulators — the one powering the GPS is enabled or disabled by the RN2483. In addition, the RAM V_BACKUP line is always powered, which means the RN2483 can power up the GPS and let it get a quick fix (thanks to the RAM backup line).

To maximize the chances of a packet making it through, he made them only have the bare essentials. There are return packets to change the tracker’s mode (such as uplink interval or how often to capture GPS). With some cloud support, [Mihai] created infrastructure to capture the packets and relay them to Telegram. He can request the last location, receive updates, and change modes.

We’ve got you covered if you’re interested in tracking some of your dog’s other habits.

Building A Local Network With LoRaWAN

At its core, the Internet is really just a bunch of computers networked together. There’s no reason that there can’t be other separate networks of computers, or that we all have to tie every computer we have to The One Internet To Rule Them All. In fact, for a lot of embedded systems, it doesn’t make much sense to give them a full network stack and Cat6e Ethernet just to report a few details about themselves. Enter LoRaWAN, a wireless LAN that uses extremely low power for Internet-of-Things devices, and an implementation of one of these networks in an urban environment.

The core of the build is the LoRaWAN gateway which sits at the top of a tall building to maximize the wireless range of all of the other devices. It’s running ChirpStack on the software side and uses a Kerlink Wigrid station to broadcast. The reported range is a little over 9 km with this setup. Other gateways can also be added, and the individual LoRa modules can report to any available gateway. From there, the gateways all communicate back to the central server and the information can be sent out to the wider network, Internet or otherwise.

The project’s creator [mihai.cuciuc] notes that this sort of solution might not be best for everyone. There are other wide area networks available, but using LoRaWAN like this would be likely to scale better as more and more devices are added to the network. For some other ways that LoRa can be used to great effect, take a look at this project which builds an off-grid communications network with it.

Water Level Sensor Does Not Use Water Level Sensor

When interfacing with the real world, there are all kinds of sensors available which will readily communicate with your microcontroller of choice. Moisture, pH, humidity, temperature, location, light, and essentially every other physical phenomenon are readily measured with a matching sensor. But if you don’t have the exact sensor you need, it’s sometimes possible to use one sensor as a proxy for another.

[Brian Wyld] needed a way to monitor the level of a remote body of water but couldn’t use a pressure or surface-level sensor, so he used a sensor typically intended for geolocation instead. This particular unit, an STM-type device with a built-in accelerometer, is attached to a rotating arm with a float at one end. As the arm pivots, the microcontroller reports its position and some software converts the change in position to a water level. It’s also paired with a LoRa radio, allowing it to operate off-grid.

Whether there is a design requirement to use an esoteric sensor to measure something more common, or a personal hardware limitation brought about by a shallow parts drawer, there’s often a workaround like this one that can accomplish the job. Whatever the situation, we do appreciate hacking sensors into other types of sensors just as much as anything else.

Casually Chirping Into The World Of LoRaWAN

While wireless communications are unquestionably useful in projects, common wireless protocols such as WiFi and Bluetooth peter out after only a number of meters, which is annoying when your project is installed in the middle of nowhere. Moving to an LTE-based or similar mobile solution can help with the range, but this does not help when there’s poor cell coverage, and it tends to use more power. Fortunately, for low-bitrate, low-power wide-area networks (LPWAN) like e.g. sensor networks, there’s a common solution in the form of LoRaWAN, as in long-range wide area network (WAN).

The proprietary LoRa RF modulation technique that underlies LoRaWAN is based on Chirp Spread Spectrum (CSS). This modulation technique is highly resistant to channel noise and fading as well as Doppler shift, enabling it to transmit using relatively low power for long distances. LoRaWAN builds on top of the physical layer provided by LoRa to then create the protocol that devices can then use to communicate with other LoRa devices.

Courtesy of global LoRaWAN gateway and software providers such as The Things Industries and ThingSpeak, it’s possible even as a hobbyist to set up a LoRaWAN-powered sensor network with minimal cost. Let’s take take a look at exactly what is involved in setting up LoRaWAN devices, and what possible alternatives to LoRaWAN might be considered. Continue reading “Casually Chirping Into The World Of LoRaWAN”

PSA: Amazon Sidewalk Rolls Out June 8th

Whether you own any Amazon surveillance devices or not, we know how much you value your privacy. So consider this your friendly reminder that Amazon Sidewalk is going live in a few weeks, on June 8th. A rather long list of devices have this setting enabled by default, so if you haven’t done so already, here’s how to turn it off.

Don’t know what we’re talking about? Our own Jenny List covered the topic quite concretely a few months back. The idea behind it seems innocent enough on the surface — extend notoriously spotty Wi-Fi connectivity to devices on the outer bounds of the router’s reach, using Bluetooth and LoRa to talk between devices and share bandwidth. Essentially, when Amazon flips the switch in a few weeks, their entire fleet of opt-in-by-default devices will assume a kind of Borg hive-mind in that they’ll be able to share connectivity.

A comprehensive list of Sidewalk devices includes: Ring Floodlight Cam (2019), Ring Spotlight Cam Wired (2019), Ring Spotlight Cam Mount (2019), Echo (3rd Gen), Echo (4th Gen), Echo Dot (3rd Gen), Echo Dot (4th Gen), Echo Dot (3rd Gen) for Kids, Echo Dot (4th Gen) for Kids, Echo Dot with Clock (3rd Gen), Echo Dot with Clock (4th Gen), Echo Plus (1st Gen), Echo Plus (2nd Gen), Echo Show (1st Gen), Echo Show (2nd Gen), Echo Show 5, Echo Show 8, Echo Show 10, Echo Spot, Echo Studio, Echo Input, Echo Flex. — Amazon Sidewalk FAQ

Now this isn’t a private mesh network in your castle, it’s every device in the kingdom. So don’t hesitate, don’t wait, or it will be too late. Grab all your Things and opt-out if you don’t want your doorbell cam or Alexa machine on the party line. If you have the Alexa app, you can allegedly opt out on all your devices at once.

Worried that Alexa is listening to you more often than she lets on? You’re probably right.

LoRa Tutorials For The DIY Masses

LoRa is the go-to tech for low power, long range wireless sensor networks. Designing with off-the-shelf modules can be a boon or a bane depending on the documentation and support. Luckily, [Renzo] has prepared a set of tutorials to get you started.
In his seven part series of write-ups, [Renzo] starts by connecting the E32 module from AliExpress to an Arduino as well as an ESP8266 to demonstrate essential communications. Then he discusses the configuration options and the library he created to make like a bit easier. Following that is a series of posts discussing transmission types as well as power saving methods including sleep modes and wake-on-radio.
The information will be extremely handy for someone starting off with the SX1276/SX1278 Wireless Modules which are relatively inexpensive as opposed to more standardized development kits. We love the abundance of fritzing diagrams, arduino code and helper library and hope someone will build on it. You can get the library from Github for your tinkering pleasure.
If you are looking for ideas for this newly discovered skill, have a look at LoRa Enabled Mailbox as well as Electric Fence Monitoring with The Things Network for a bit of IoT action.

AAA Powered LoRa Mailbox Sensor Goes The Distance

As more of the world’s communication moves into the electronic realm, a casualty has come in the physical mail. Where once each new day might have brought with it a bulging mailbox, today it’s not uncommon for days to pass with not even so much as a bill or a coupon book. For [Eivholt] this presents a problem: he doesn’t want to miss a parcel but most visits to the mailbox are futile. His solution is a LoRa-connected mailbox monitor that sips power from a pair of AAA batteries to the extent that so far it’s run for over two years on a single set.

At its heart is a single board, a Talk2 Whisper Node. This packs a low-power version of the ATmega328 microcontroller alongside a LoRa radio and an efficient power regulator allowing it to draw only 8.70 uA in standby mode, waking up only for extremely short periods to check for mail and report via LoRa to The Things Network. The sensor is simply a microswitch, selected after finding a reed switch problematic to install. Finally an SDR was used to debug the operation of the radio.

The write-up also provides an introduction to extreme low power projects, including some tips on measuring such tiny currents. Even if you have no interest in a mailbox, any tricks that can help maximize power efficiency are always worth taking a look at. Check out the video after the break to see this radio-equipped mailbox in action.

Continue reading “AAA Powered LoRa Mailbox Sensor Goes The Distance”