A Mobile Terminal For Guerrilla Communications

May 4, 2018 by Tom Nardi 25 Comments

We use the Internet to do everything from filing our taxes to finding good pizza, but most critically it fulfills nearly all of our communication needs. Unfortunately, this reliance can be exploited by those pulling the strings; if your government is trying to do something shady, the first step is likely to be effecting how you can communicate with the outside world. The Internet is heavily censored and monitored in China, and in North Korea the entire country is effectively running on an intranet that’s cutoff from the wider Internet. The need for decentralized information services and communication is very real.

While it might not solve all the world’s communication problems, [::vtol::] writes in to tell us about a very interesting communication device he’s been working on that he calls “Hot Ninja”. Operating on the principle that users might be searching for accessible Wi-Fi networks in a situation where the Internet has been taken down, Hot Ninja allows the user to send simple messages through Wi-Fi SSIDs.

We’ve all seen creatively named Wi-Fi networks before, and the idea here is very much the same. Hot Ninja creates a Wi-Fi network with the user’s message as the SSID in hopes that somebody on a mobile device will see it. The SSID alone could be enough depending on the situation, but Hot Ninja is also able to serve up a basic web page to devices which actually connect. In the video after the break, [::vtol::] even demonstrates some rudimentary BBS-style functionality by presenting the client devices with a text field, the contents of which are saved to a log file.

In terms of hardware, Hot Ninja is made up of an Arduino Mega coupled to three ESP8266 boards, and a battery to keep it all running for up to eight hours so you can subvert a dictatorship while on the move. The user interface is provided by a small OLED screen and a keyboard made entirely of through-hole tactile switches, further reinforcing the trope that touch-typing will be a must have skill in the dystopian future. It might not be the most ergonomic device we’ve ever seen, but the fact it looks like something out of a Neal Stephenson novel more than makes up for it in our book.

This is not the first time we’ve seen Wi-Fi SSIDs used as a method of communication, thanks largely to how easy the ESP8266 makes it. For his part, [::vtol::] has previously experimented with using them to culturally enrich the masses.

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Accessing Blockchain On ESP8266 Using The NodeMCU Board

May 2, 2018 by Sean Boyce 24 Comments

Blockchains claim to be public, distributed, effectively immutable ledgers. Unfortunately, they also tend to get a little bit huge – presently the Bitcoin blockchain is 194GB and Ethereum weighs in at 444GB. That poses quite an inconvenience for me, as I was looking at making some fun ‘Ethereum blockchain aware’ gadgets and that’s several orders of magnitude too much data to deal with on a microcontroller, not to mention the bandwidth cost if using 3G.

Having imagined a thin device that I could integrate into my mobile phone cover (or perhaps… a wallet?) dealing with the whole blockchain was clearly not a possibility. I could use a VPS or router to efficiently download the necessary data and respond to queries, but even that seemed like a lot of overhead, so I investigated available APIs.

As it turns out, several blockchain explorers offer APIs that do what I want. My efforts get an ESP8266 involved with the blockchain began with two of the available APIs: Ethplorer and Etherscan.

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Checking The Weather Without A Window

April 27, 2018 by Drew Risinger 9 Comments

Making a weather display is great because it’s a simple project that shows off some skills and has an obvious daily use. So [ACROBOTIC Industries] decided to make an easy kit for the Hackaday Prize to make weather displays even more accessible.

Calling it the ESPecter, [ACROBOTIC Industries] wanted to make this a simple project for anyone, regardless of skill with a soldering iron or Arduino toolkit. So they decided to base the guts on common components that can be put together easily, specifically a Wemos Mini D1 with an OLED shield as a bright display. They also designed a cool tiltable 3D-printed enclosure for this small device so that you can orient it to your eye level.

While they already have a breadboarded prototype, and a 3D printed case, some software work remains to make the project really shine. They plan to add nice features like a web interface to configure location and network information, alerts, additional locations, and historical weather data. They also want to create a weather library to display well on a low-resolution screen and add battery operation.

We look forward to seeing the final version later in the Hackaday Prize!

This isn’t the first weather project we’ve seen around here. Other variants include mirror weather displays, an ESP8266-based weather monitoring station, a very low-power weather station, and this roundup of weather displays which might give you some inspiration.

Reprogramming Cheap WiFi Outlets

April 16, 2018 by Brian Benchoff 52 Comments

If you want to retrofit your home with smart outlets and lightbulbs, bust out your wallet. You can easily spend forty dollars for a smart light bulb at your local home supply store, and strips of smart sockets could cost sixty. When [coogle] found a WiFi-enabled four-outlet power strip on Amazon, he couldn’t resist. Sure, the no-name strip would be locked down behind a stupid iPhone interface and will probably turn your house into a botnet, but never mind that: you can easily reprogram these power strips to be whatever you want.

After receiving these power strips and tearing them open, [coogle] found exactly what you would expect from a no-name white goods manufacturer. There’s a board with an Espressif chip and a WiFi antenna, and a second board with a few relays, with a few wires connecting the two. You only need to browse AliExpress for a few minutes to figure out what’s going on here. The brains of the outfit are in the ESP8266, and if you can control that, you have your own Internet of Power Strips.

The problem, then, was reprogramming the ESP8266. This was a version of the chip [coogle] hadn’t seen before, but a quick query with the Google Mother Brain revealed it was a WT8266-S1 module, with all the pins required for programming easily accessible on a convenient header. After connecting this header up to an ESP programming board, [coogle] had all the relevant information including the capacity of the Flash. There’s still a bit more work to make this a functional WiFi power outlet, namely figuring out which GPIOs and wires connect to which relays, but this is effectively a completely Open IoT device right now. All you have to do is bring your own firmware.

Mc Lighting Takes The Pain Out Of Blinking

April 14, 2018 by Elliot Williams 1 Comment

If you want to blink a ton of WS2812-alike LED pixels over WiFi, the hardware side of things is easy enough: an LED strip, and ESP8266 unit, and a beefy enough power supply to feed them. But the software side — that’s where it can be a bit of a pain.

Enter Mc Lighting. It makes the software side of things idiot-proof. Flash the firmware onto the ESP8266, and you’ve got your choice of REST, WebSockets, or MQTT to get the data in. This means that it’ll work with Homekit, NodeRed, or an ESP-hosted web interface that you can pull up from any smartphone.

The web interface is particularly swell, and has a bunch of animations built in. (Check out the video below.) This means that you can solder some wires, flash an ESP, and your least computer-savvy relatives can be controlling the system in no time. And speaking of videos, Mc Lighting’s author [Tobias] has compiled a playlist of projects that use the library, also just below. The docs on GitHub are great, and also check out the wiki.

So what are you waiting for? Do you or your loved ones need some blink in your life? And while you’re ordering LED strips, get two. You’re going to want to build TWANG! as well.

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Audio Hacking With The ESP8266

April 12, 2018 by Jenny List 23 Comments

If you study the specifications of the ESP8266 WiFi-enabled microcontroller, you will notice that it features an I2S audio interface. This is a high-speed serial port designed to deliver 16-bit audio data in a standard format, and has its origins in consumer audio products such as CD players. It would be usual to attach a dedicated DAC to an I2S interface to produce audio, but [Jan Ostman]’s synthesiser projects eschew that approach, and instead do the job in software. His I2S interface pushes out a pulse density modulated data stream in the same manner as a 1-bit DAC, meaning that the only external components required to produce audio are a simple low-pass filter. He’s posted a video of the synth in action, which we’ve placed below the break.

The example he gives us is a basic clone of a Roland 909 drum machine, and he takes us through the code with extensive examples including MIDI. He’s using the Wemos D1 Mini board, but the same could be replicated with many other ESP8266 platforms.

We’ve featured [Jan]’s work many times before, from his minimalist Atmel-based devices through to small but perfectly-formed complete instruments.

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Need A Thousand Extra PWM Pins?

April 11, 2018 by Al Williams 58 Comments

If your Arduino runs out of I/O lines, you can always add one of the several I/O expander chips that takes a serial interface to set its several pins. Or perhaps you could buy something like an Arduino Mega, with its extra sockets to fulfil your needs. But what would you do if you really needed more pins, say a thousand of them? Perhaps [Brian Lough] has the answer. OK, full disclosure: If you really need a thousand, the video isn’t exactly for you, as he shows you how to add up to 992 PWM outputs. The chip he uses works with any microcontroller (the video shows an ESP8266), and we suppose you could use two daisy chains of them and break the 1,000 barrier handily.

We like how short the video is (just two minutes; see below) as it gets right to the point. The PCA9685 chip gives you 16 12-bit PWM channels via an I2C interface. You can daisy chain up to 62 of the boards to get the 992 outputs promised.

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