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.
Is it just me or did January seem to last for about three months this year? A lot has happened since the turn of the decade 31 days ago, both in the normie world and in our space. But one of the biggest pieces of news in the hacker community is something that won’t even happen for four more months: Hackaday Belgrade. The annual conference in Hackaday’s home-away-from-home in Serbia was announced, and as usual, one had to be a very early bird to score discount tickets. Regular tickets are still on sale, but I suspect that won’t last long. The call for proposals for talks went out earlier in the month, and you should really consider standing up and telling the world what you know. Or tell them what you don’t know and want to find out – there’s no better way to make connections in this community, and no better place to do it.
Someone dropped a tip this week about the possible closing of Tanner Electronics, the venerable surplus dealer located in Carrollton, Texas, outside of Dallas and right around the corner from Dallas Makerspace. The report from someone visiting the store is that the owner has to either move the store or close it down. I spoke to someone at the store who didn’t identify herself, but she confirmed that they need to either downsize or close. She said they’re actively working with a realtor and are optimistic that they’ll find a space that fits their needs, but the clock is ticking – they only have until May to make the change. We covered Tanner’s in a 2015 article on “The Death of Surplus”. It would be sad to lose yet another surplus store; as much as we appreciate being able to buy anything and everything online, nothing beats the serendipity that can strike walking up and down aisles filled with old stuff. We wish them the best of luck.
Are you finding that the smartphone in your pocket is more soul-crushing than empowering? You’re not alone, and more and more people are trying a “digital detox” to free themselves from the constant stimulation. And there’s no better way to go about this than by turning your smartphone into a not-so-smart phone. Envelope, a paper cocoon for your phone, completely masks the screen, replacing it with a simple printed keypad. A companion app allows you to take and make phone calls or use the camera, plus provides a rudimentary clock, but that’s it. The app keeps track of how long you can go before unwrapping your phone and starting those sweet, sweet dopamine hits again. It reminds us a bit of the story we also saw this week about phone separation anxiety in school kids, and the steps schools are taking to mitigate that problem.
We saw a lot of articles this week on a LoRaWAN security vulnerability. The popular IoT network protocol has been billed as “secure by default”, but a white paper released by cybersecurity firm IOActive found a host of potential attack vectors. Their main beef seems to be that client devices which are physically accessible can be reverse engineered to reveal their encryption keys. They also point out the obvious step of taking the QR code off of client devices so an attacker can’t generate session keys for the device.
And finally, the mummy speaks! If you ever wondered what the voice of someone who lived 3,000 years ago sounded like, wonder no more. Using computed tomography (CT) data, scientists in the UK and Germany have recreated the vocal tract of Nesyamun, an Egyptian scribe and priest from the time of pharaoh Rameses XI. He died in his mid-50s, and his mummified remains have been studied since the 1800s. CT data was used to 3D-print Nesyamun’s larynx and nasopharynx, which was then placed atop a “Vocal Tract Organ”, possibly the strangest musical instrument in existence. The resulting vowel-like utterance is brief, to say the least, but it’s clear and strong, and it’s pretty impressive that we can recreate the voice of someone who lived and died three millennia ago.
It’s hard to beat the fidelity and durability of printed text on paper. But the e-paper display gets pretty close, and if you couple it will great design and dependable features, you might just prefer an e-reader over a bookshelf full of paperbacks. What if the deal is sweetened by making it Open Hardware? The Open Book Project rises to that challenge and has just been named the winner of the Take Flight with Feather contest.
This e-reader will now find its way into the wild, with a small manufacturing run to be put into stock by Digi-Key who sponsored this contest. Let’s take a closer look at the Open Book, as well as the five other top entries.
Making sure that an electric fence which is keeping one’s cattle and sheep from wandering off is still working properly seems like a fairly daunting task, especially when this fence is quite a distance from one’s home so checking up on it is time-consuming. After a friend of [kiu] got called a few times by the police because some of the sheep had pulled a prison break, the obvious technological solution was to IoT-enable the fence with LoFence.
This solution is nothing if not elegant in its simplicity. For phoning home with status data, the system uses the Microchip RN2483 IC, which handles pretty much all aspects of LoRaWAN, so that one merely has to send data to its serial interface to transmit. Because this system uses The Things Network (TTN) there are no service costs due to the low data rates. This was the easy part, aside from having to add a LoRaWAN gateway to boost the signal in the area with the electric fence.
With that side covered, the rest of the build features an AVR ATmega328p MCU, a resistor divider and op-amp (TLV9062) along with some passives. The resulting circuit measures voltage, essentially to detect whether the fence is still forming a full circuit. Hacking into the little box that energizes the fence might be a possible upgrade there, but at least it is a fairly uncomplicated way to measuring things. Electric fences do work best with a voltage on them, after all.
At the other end of the LoRaWAN network, the data is parsed and analyzed by a service so that it can be displayed on a Grafana dashboard, ensuring that a single glance suffices to see the current state of the fence and whether one has to dash out in the rain at 1 AM to fix it or not.
Making wine isn’t just about following a recipe, it’s a chemical process that needs to be monitored and managed for best results. The larger the batch, the more painful it is to have something go wrong. This means that the stakes are high for small vineyards such as the family one [Mare] works with, which have insufficient resources to afford high-end equipment yet have the same needs as larger winemakers. The most useful thing to monitor is the temperature profile of the fermentation process, and [Mare] created an exceptional IoT system to do that using LoRa wireless and solar power.
It’s not enough just to measure temperature of the fermenting liquid; viewing how the temperature changes over time is critical to understanding the process and spotting any trouble. [Mare] originally used a Raspberry Pi, I2C temperature sensor, and a Wi-Fi connection to a database to do the monitoring. This was a success, but it was also overkill. To improve the system, the Raspberry Pi was replaced with a LoRaDunchy board, an STM-based module of [Mare]’s own design which is pin-compatible with the Arduino Nano. It includes a battery charger, power management, and LoRa wireless communication. Adding a solar cell and lithium-polymer battery was all it took to figuratively cut the power cord.
Sensing the temperature of fermentation is done by sealing the temperature sensor into a thin aluminum tube, and lowering that into the vat. There it remains, with the LoRaDunchy board periodically waking up to read the sensor and report the tempurature over LoRa before going back to sleep, all the while sipping power from the battery which in turn gets recharged with solar power.
It’s an elegant system that has already paid off. A 500 litre vat of wine generated an alarm when the temperature rose above 24 Celsius for 10 minutes. An email alert allowed the owner to begin mixing the solution and add ice water to put the brakes on the runaway reaction. The temperature dropped and slow fermentation resumed, thanks to the twin powers of gathering the right data, then doing something meaningful with it.
Vineyards and LoRa have joined forces before, for example in the Vinduino project which aims to enable water-smart farming. If you’re unfamiliar with LoRa in general, the LoRa on the ESP32 project page contains a good primer, and if the antenna on the module shown here looks familiar to you it’s because we recently featured [Mare]’s guide on making DIY LoRa antennas from salvaged wire.
Back in the early days of Arduino proliferation (and before you ask, yes we realize there was a time before that too), wireless was a strange and foreign beast. IR communication was definitely a thing. And if you had the funds there was this cool technology called ZigBee that was available, often in funny blue house-shaped XBee boards. With even more funds and a stomach for AT commands you could even bolt on a 2G cell radio for unlimited range. WiFi existed too, but connecting it to a hobbyist ecosystem of boards was a little hairier (though maybe not for our readership).
But as cell phones pushed demand for low power wireless forward and the progression of what would become the Internet of marking Terms (the IoT, of course) began, a proliferation of options appeared for wireless communication. Earlier this week we came across a great primer on some of the major wireless technologies which was put together by Digikey earlier in the year. Let’s not bury the lede. This table is the crux of the piece:
There are some neat entries here that are a little less common (and our old friend, the oft-maligned and never market-penetrating ZigBee). It’s actually even missing some entries. Let’s break it down:
- Extremely short range: Just NFC. Very useful for transferring small amount of sensitive information slowly, or things with high location-relevance (like between phones that are touching).
- Short range: BLE, Zigbee, Z-Wave, etc. Handy for so-called Personal Area Networks and home-scale systems.
- Medium/long range: Wifi, Bluetooth, Zigbee, Z-Wave, LoRaWAN: Sometimes stretching for a kilometer or more in open spaces. Useful for everything from emitting tweets to stitching together a mesh network across a forrest, as long as there are enough nodes. Some of these are also useful at shorter range.
- Very Long range/rangeless: Sigfox, NB-IoT, LTE Category-0. Connect anywhere, usually with some sort of subscription for network access. Rangeless in the sense that range is so long you use infrastructure instead of hooking a radio up to a Raspberry Pi under your desk. Though LoRa can be a fun exception to that.
You’re unlikely to go from zero to custom wireless solution without getting down into the mud with the available dev boards for a few different common protocols, but which ones? The landscape has changed so rapidly over the years, it’s easy to get stuck in one comfortable technology and miss the appearance of the next big thing (like how LoRaWAN is becoming new cool kid these days). This guide is a good overview to help catch you up and help decide which dev kits are worth a further look. But of course we still want to hear from you below about your favorite wireless gems — past, present, and future — that didn’t make it into the list (we’re looking at you 433 MHz).