A browse through his collected works will tell you that [El Kentaro] loves to build electronics into interesting enclosures, so when he realized there’s enough room inside a 150 ml plastic syringe to mount an ESP8266, a battery, and a copious amount of RGB LEDs, the “Packet Injector” was the inescapable result.
Granted, the current incarnation of this device doesn’t literally inject packets. But [El Kentaro] wasn’t actually looking to do anything malicious, either. The Injector is intended to be a fun gag for him to bring along to the various hacker cons he finds himself at, like his DEAUTH “bling” necklace we saw at DEF CON 26, so having any practical function is really more icing on the cake than a strict requirement.
In the end, the code he came up with for the Adafruit Feather HUZZAH that uses the FakeBeaconESP8266 library to push out fictitious networks on demand. This is a trick we’ve seen used in the past, and makes for a relatively harmless prank as long as you’re not pumping out any particularly unpleasant SSIDs. In this case, [El Kentaro] punctuates his technicolor resplendency with beacons pronouncing “The WiFi Doctor is Here.”
But the real hack here is how [El Kentaro] controls the device. Everything is contained within the syringe chamber, and he uses a MPL3115A2 I2C barometric pressure sensor to detect when it’s being compressed. If the sensor reads a pressure high enough over the established baseline, the NeoPixel Ring fires up and the fake beacon frames start going out. Ease up on the plunger, and the code detects the drop in pressure and turns everything back off.
If this build has piqued your interest, [El Kentaro] gave a fascinating talk about his hardware design philosophy during the WOPR Summit that included how he designed and built some of his “greatest hits”; including a Raspberry Pi Zero enclosure that was, regrettably, not limited to external use.
WiFi was the killer technology that made home networking easy. No more messing around with hubs and cables and drilling holes in walls, simply turn the devices on and hit connect. Over time the speed and range has increased, but those with larger houses or granny flats out back have suffered. There are tricks to boost range however, and some of them involve cookware.
The clever hack here is to use a metal strainer as a parabolic reflector, to capture signals and focus them onto the PCB antenna in a USB WiFi dongle. The strainer is drilled out, and a USB extension cable has its female end glued into the base. This allows the dongle to be positioned inside the strainer. For best results, the dongle should be positioned so that its antenna elements are sitting at the focal point of the parabola; this can be determined through mathematics or simply by experimenting with positions to see what gives the best signal strength.
It’s a design that is quite directional, and should help boost signals as well as block out those from unwanted stations. The build is simple, and can even be tripod mounted which helps with aiming and looks cool to boot.
For many, WiFi antenna hacks are old school, but it’s always good to keep the techniques in mind as you never know when it will come in handy to solve a new problem. Some crazy things are possible with the right gear, too.
The ESP8266 is a great processor for a lot of projects needing a small microcontroller and Wi-Fi, all for a reasonable price and in some pretty small form factors. [Simon] used one to build a garage door opener. This project isn’t really about his garage door opener based on a cheap WiFi-enabled chip, though. It’s about the four year process he went through to learn how to develop on these chips, and luckily he wrote a guide that anyone can use so that we don’t make the same mistakes he did.
The guide starts by suggesting which specific products are the easiest to use, and then moves on to some “best practices” for using these devices (with which we can’t argue much), before going through some example code. The most valuable parts of this guide especially for anyone starting out with these chips are the section which details how to get the web server up and running, and the best practices for developing HTML code for the tiny device (hint: develop somewhere else).
[Simon] also makes extensive use of the Chrome developers tools when building the HTML for the ESP. This is a handy trick even outside of ESP8266 development which might be useful for other tasks as well. Even though most of the guide won’t be new to anyone with experience with these boards, there are a few gems within it like this one that might help in other unrelated projects. It’s a good read and goes into a lot of detail about more than just the ESP chips. If you just want to open your garage door, though, you have lots of options.
The Internet is a wild and wooly place where people can spout off about anything with impunity. If you sound like you know what you’re talking about and throw around a few bits of the appropriate jargon, chances are good that somebody out there will believe whatever you’re selling.
Case in point: those that purport that watches rated for 300-meter dives will leak if you wiggle them around too much in the shower. Seems preposterous, but rather than just dismiss the claim, [Kristopher Marciniak] chose to disprove it with a tiny wireless pressure sensor stuffed into a dive watch case. The idea occurred to him when his gaze fell across an ESP-01 module next to a watch on his bench. Figuring the two needed to get together, he ordered a BMP280 pressure sensor board, tiny enough itself to fit anywhere. Teamed up with a small LiPo pack, everything was stuffed into an Invicta dive watch case. A little code was added to log the temperature and pressure and transmit the results over WiFi, and [Kristopher] was off to torture test his setup.
The first interesting result is how exquisitely sensitive the sensor is, and how much a small change in temperature can affect the pressure inside the case. The watch took a simulated dive to 70 meters in a pressure vessel, which only increased the internal pressure marginally, and took a skin-flaying shower with a 2300-PSI (16 MPa) pressure washer, also with minimal impact. The video below shows the results, but the take-home message is that a dive watch that leaks in the shower isn’t much of a dive watch.
Hats off to [Kristopher] for doing the work here. We always love citizen science efforts such as this, whether it’s hardware-free radio astronomy or sampling whale snot with a drone.
Continue reading “Torturing An Instrumented Dive Watch, For Science”
Access to fast and affordable internet is a big issue in the USA, even in a major metropolis such as New York City. Amidst a cartel of ISPs who simply will not deliver, a group of NYC inhabitants first took it upon themselves to ease this situation by setting up their own mesh-based internet connections way back in 2013. Now they will be installing a new Supernode to take the installation base far beyond the current 300 buildings serviced.
As a community project, NYC Mesh is run as a non-profit organization, with its community members supporting the effort through donations, along with partnerships with businesses. Its router hardware consists out of off-the-shelf equipment (with a focus on the Ubiquiti NanoStation NSM5) that get flashed with custom firmware containing the mesh routing functionality.
As this article by Vice mentions, NYC Mesh is one of 750 community-led broadband projects in the US. Many of those use more traditional fixed wiring with distribution lines, but NYC Mesh focuses fully on wireless (WiFi) links with wireless mesh networking. This has the obvious benefit that given enough bandwidth on the Supernodes that hook into the Internet exchange points (IXP) and an efficient mesh routing protocol, it’s quick and easy to hook up new clients and expand the network.
The obvious downsides of using WiFi and RF in general is that they are not immune to outside influences, such as weather (rain), RF interference (including from other WiFi stations) and of course fairly limited range if there’s no direct line of sight. In a densely populated city such as NYC this is not much of an issue, with short hops between roof tops.
Making a programming jig becomes exponentially more difficult after two pins and who would even consider building one if they were not setting up more than twenty boards? If it were easy for novices to construct jigs, we might all have a quiver of them on the shelf next to our microprocessors. Honestly, a tackle box full of homemade programming fixtures sounds pretty chic. The next advantage to ditching the demo boards is that bare processors take up less room and don’t draw power for unnecessary components like unused voltage regulators and LEDs. [Albert David] improves the return-on-time-investment factor by showing us how to repurpose a WeMos board to program a bare ESP8266 module.
[Albert]’s concept can apply to many other surface-mount chips and modules. The first step is to buy a demo board which hosts a programmable part and remove that part. Since you’ve exposed some solder pads in the process, put pogo pins in their place. Pogo pins are small spring-loaded probes that can be surface mounted or through-hole. We’ve used them for programming gorgeous badges and places where the ESP8266 has already been installed. When you are ready to install your software, clamp your Franken-porcupine to the controller and upload like normal. Rinse, wash, repeat. We even get a view of the clamp [Albert] uses.
The world of radio controlled aircraft used to be an expensive and exclusive hobby, limited to those with the time and money to invest in difficult builds and pricey radio gear. More recently, the hobby has become more accessible, with cheap ready to fly planes available that can be flown in smaller spaces like suburban parks. [Ravi Butani] has built just such a plane, and you can even fly it with your smartphone!
An ESP8266 does double duty here as both the brains and the communication system. A custom smartphone app communicates with the plane over WiFi. Touching the screen increases the throttle, while steering is achieved through tilting the phone. There’s also monitoring of signal strength and battery level, with the phone vibrating if the plane is getting out of range or low on battery.
Flight control is via differential thrust, with power coming courtesy of two small DC motors controlled by tiny SMD MOSFETs. The plane flies remarkably well in still conditions, and the WiFi connection is stable in an open park environment. [Ravi] reports that control is possible at a range of around 70 meters using a Motorola G5S smartphone.
Despite the simplicity of the build and the low cost of the components, the final product performs admirably. It would be a great weekend project, and at the end of it, you get to go and fly your new plane! If you’re worried about keeping your batteries charged, don’t worry – there’s a solution for that. Video after the break.
Continue reading “WiFi Controlled Plane Is Cheap Flying Fun”