[Heath Paddock] wanted to confound his friends with a game that mimics an escape room in a box. About six months after starting, he had this glorious thing completed. It’s a hardware version of a game called Keep Talking and Nobody Explodes where players have five minutes to defuse a suitcase bomb. This implementation requires at least two players, one with the box-bomb itself, and one who holds all the knowledge but can’t see the box-bomb to defuse it.
[Heath]’s version has twice as many modules as the original game, each hand-wired one driven by an Arduino. One of the modules is an LED maze. There are two green anchor LEDs in one of six configurations, and and blue and a red LED.
The object is to move the blue LED next to the red one without touching any walls. Of course, the box-holder can’t see the walls and must describe the configuration of the anchor LEDs to their partner in order to get started.
All of the modules are quite different, which likely makes for an extremely fun and challenging five minutes. [Heath] reports that getting inter-module communication down was a long road. Eventually, [Heath] settled on a mesh network configuration and connected everything in a big loop. Be sure to check out the walk-through video after the break.
Continuing the concept of saving planet Earth with gnarly, repeatable hacks, the fifth and final challenge of the 2022 Hackaday Prize is all about making the world better with smart and sustainable hardware. While the focus is still on saving the planet, this time, anything goes. Does your project not fit within the confines of a previous challenge? Here is your last chance to enter the 2022 Hackaday Prize: Start your entry today!
The Save the World Wildcard challenge starts right now and runs until October 16th. As with previous rounds, we’ll award one of ten $500 prizes to each finalist, and the best projects will have a chance at the overall 2022 Hackaday Prize. So get hacking!
Following along with the 2022 Hackaday Prize theme on building a better world by doing what we all do best – hacking together solutions – the fourth round of the Prize focuses on making our local communities more resilient against and sensitive to severe weather and environmental disasters. Whether it’s an early warning system for wildfires or a distributed communication network that will keep working even when the cell phone service goes down, we’re challenging you to help make your world safer by reacting sooner and better. Get your project entered now!
We love systems that help us monitor our environments, and not just for idle curiosity or citizen science. Sometimes it’s critical. We’ve seen monitors aimed at giving you a personal particulate air quality indicator, especially helpful for people with respiratory problems when downstream of a forest fire.
One of the design requirements for the networks that evolved into the Internet was the ability to keep functioning, even if some nodes or links were disabled or destroyed in war. The packet-switched architecture that still powers today’s Internet is a direct result of that: if one link stops functioning, information is automatically re-routed towards its intended destination. However, with tech giants occupying increasingly large parts of the global internet, an outage at one of them might still cause major disruption. In addition, a large-scale power interruption can disable large parts of the network if multiple nodes are connected to the same grid.
Enter the LoRa Birdhouse project by the Wellesley Amateur Radio Society that solves those two problems, although admittedly at a very small scale. Developed by amateur radio operators in eastern Massachusetts, it’s basically a general-purpose LoRa-based packet-switching network. As it’s based on open-source hardware and commonly available components, its design allows anyone to set up a similar network in their own area.
The network is built from nodes that can receive messages from their neighbors and pass them on towards their final destination. Each node contains a Semtech SX1276 transceiver operating in the 902-928 MHz band, which gets its data from an ESP32 microcontroller. The nodes are placed in strategic locations outside and are powered by solar panels to reduce their ecological footprint, as well as to ensure resilience in case of a power outage. To make the whole project even more eco-friendly, each node is built into a birdhouse that provides shelter to small birds.
Users can access the network through modified network nodes that can be hooked up to a PC using a USB cable. Currently, a serial terminal program is the only way to interact with the network, although a more user-friendly interface is being planned. FCC rules also require all users (except any avian residents) to be licensed amateur radio operators, and all traffic to remain unencrypted. Tests have shown that one kilometer between nodes can work in the right conditions, enabling the deployment of networks across reasonably large areas.
While the Birdhouse Network might not be a plug-and-play internet replacement in case of a nuclear apocalypse, it does provide an excellent system to experiment with packet-switching wireless network technology. We’ve seen similar LoRa-based network initiatives like Qmesh, Cellsol and Meshtastic, all of which provide some way to communicate wirelessly without requiring any centralized hardware.
In a flooded mesh network every node repeats every message it receives. This has the theoretical advantage of making the network self-healing if a single node stops working, but often just means that the nodes will interfere with each other. Thanks to some characteristics of LoRa, [Dan] is using several tricks to get around this packet collision problem. LoRa network can make use of the “capture effect”, which allows a receiver to differentiate between two packets if the power level difference is large enough. This is further improved by adding forward error correction and slightly changing the frequency and timing of the LoRa chirps. QMesh also implements TDMA (Time Division Multiple Access) by splitting transmission into time slots, and only transmitting every third slot. This means it is operating on a 33% duty cycle, which is much higher than the 0.1%-10% allowed on license-free ISM-bands, which legally limits it to the ham bands.
On the hardware side, [Dan] has been using the STM32 NUCLEO-144 development boards with F4/L4/F7/H7 microcontrollers and a custom shield with a 1 W LoRa module and OLED screen. While [Dan] wants to eventually build handheld radios, he plans to first develop small FM repeaters that encode voice as codec2 and use QMesh as a backhaul. QMesh is still under development, but we would love to see the results of some long-range testing, and we are excited to see how it matures.
If your interested in a more basic LoRa-based human-to-human messaging system, take a look at Meshtastic. It’s been going very rapidly over the past year. To learn more about LoRa and other digital modulation schemes, check out the crash course we did with an SDR a while back.
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.
That electrical meter on the side of your house might not look like it, but it’s pretty packed with technology. What was once a simple electromechanical device that a human would have to read in person is now a node on a far-flung network. Not only does your meter total up the amount of electricity you use, but it also talks to other meters in the neighborhood, sending data skipping across town to routers that you might never have noticed as it makes its way back to the utility. And the smartest of smart meters not only know how much electricity you’re using, but they can also tease information about which appliances are being used simply by monitoring patterns of usage.
While all this sounds great for utility companies, what does it mean for the customers? What are the implications of having a network of smart meters all talking to each other wirelessly? Are these devices vulnerable to attack? Have they been engineered to be as difficult to exploit as something should be when it’s designed to be in service for 15 years or more?
These questions and more burn within [Hash], a hardware hacker and security researcher who runs the RECESSIM reverse-engineering wiki. He’s been inside a smart meter or two and has shared a lot of what he has learned on the wiki and with some in-depth YouTube videos. He’ll stop by the Hack Chat to discuss what he’s learned about the internals of smart meters, how they work, and where they may be vulnerable to attack.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about. Continue reading “Inside Smart Meters Hack Chat”→