ESP8266

649 Articles

Mine Bitcoin With An ESP8266

January 3, 2018 by 25 Comments

With all the hype surrounding cryptocurrencies and the current high not quite so high but still pretty eye-watering price of Bitcoin, there are some things which might once have been pure folly that could now be deemed worthy of pursuit. There is an excavation mission being considered to unearth a hard drive containing an early Bitcoin wallet in a Welsh landfill, for instance. But a more approachable task for you may be the possibility of mining using minimal hardware.

Take [Merlot Machina]’s project for example, implementing a Bitcoin miner on an ESP8266. Part of this is the timeless pursuit of answering the joke question: “Will it mine Bitcoin”, and the other part is looking at this like a lottery ticket. Is it a worthwhile punt at a prize for a minimal investment?

He gives us a rundown of some of the statistics involved, and comes away with the conclusion that it is something like a not-very-good lottery ticket. The ESP performs 1200 hashes per second while the entire Bitcoin community manages about 1.2 exahashes per second. This he calculates gives him a 1 in 1016 chance of mining a block every ten minutes, which for the tiny cost of an ESP and its relatively frugal power budget is a chance he sees as worth taking.

So far he has implemented the hashing algorithm and verified it against a known hash on an already-mined block. At this point though he’s hit a roadblock in the need to run Bitcoin core on a server to keep the ESP supplied with new block headers, so the ESP miner remains a proof of concept. The write-up is still an interesting read though, and given that many readers will have a few spare ESP boards it’s possible that one of you may take it to the next level and Win It Big. If that’s you, you’ll be able to sit on your private island sipping a cool drink, and laugh at the commenters who said it would never happen. Meanwhile here at Hackaday we’ll stick to tried-and-trusted revenue generation strategies, such as bringing you the latest hardware hacks.

This might seem a peculiarly slow miner, but it’s not the slowest we’ve seen by any means. The ever-prolific [Ken Shirriff] has tried it on an IBM 1401 mainframe and a Xerox Alto, and you can of course do it the old-fashioned way.

An IoT Christmas Tree For Your Hacker-Mas Celebrations

December 31, 2017 by No comments

Smart Christmas trees may soon come to mean something more than a fashionably decorated tree. Forging ahead with this new definition, [Ayan Pahwa], with help from [Akshay Kumar], [Anshul Katta], and [Abhishek Maurya] turned their office’s Christmas Tree into an IoT device you can watch live!

As an IoT device, the tree relies on the ever-popular ESP8266 NodeMCU — activated and controlled by Alexa, as well as from a web page. The LEDs for the tree — and the offline-only tree-topper controlled by an Arduino Pro Mini — are the similarly popular Neopixels.

For those viewing online, a Raspberry Pi and camera have been attached to this project to check out the tree’s lighting. To make that possible, [Pahwa] had to enlist the use of ngrok to make the Pi’s –normally — LAN-only camera server accessible over the internet. The aforementioned web page was coded in Javascript/CSS and hosted on a server running an instance of Ubuntu 16.04.

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Espple: A Wireless Apple 1 On An ESP8266

December 30, 2017 by 23 Comments

The Apple 1 was one of the three big hobbyist computers that burst onto the scene in 1977. Unlike the PET 2001 and the TRS-80, only a couple hundred Apple 1s were ever produced, and with only a handful in existence today, you’ll have to fork out some serious money to get a Wozniak original for yourself.

The Apple 1 experience is easily emulated, of course, but this ESP8266 emulates the Apple 1 on hard mode. Dubbed the Espple by its creator [Hrvoje Cavrak], it emulates the 6502-based original in all its 1-MHz glory, while providing 20-kB of RAM, a considerable upgrade over the 4-kB standard. The complete original character set is provided for that old-timey feel, and there’s a BASIC interpreter ready to go. The kicker here, though, is that the emulator is completely wireless. You telnet into the 8266 rather than connecting a keyboard directly, and video is transmitted over-the-air using a GPIO pin as a 60-MHz PAL transmitter. A short length of wire is all you need to transmit to an analog PAL TV on channel 4; the video below shows a little BASIC code running and a low-res version of Woz himself.

You’ll find Apple emulators aplenty around these parts, everything from an Apple ][ on an Arduino Uno to a tiny Mac on an ESP32. There hasn’t been much in the way of Apple 1 emulations, though, at least until now.

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Arduino Trivia Box Is A Gift Unto Itself

December 29, 2017 by 3 Comments

There’s something about impressing strangers on the Internet that brings out the best in us. Honestly, we wouldn’t be able to run this site otherwise. A perfect example of this phenomenon is the annual Reddit Secret Santa, where users are challenged to come up with thoughtful gifts for somebody they’ve never even met before.

For his entry into this yearly demonstration of creativity, [Harrison Pace] wanted to do something that showcased his improving electronic skills while also providing something entertaining to the recipient. So he came up with a box of goodies which is unlocked by the successful completion of a built-in trivia game tailored around their interests. If this is how he treats strangers, we can’t wait to see what he does for his friends.

Hardware packed into the lid so the box itself remains empty.

There’s quite a bit of hardware hidden under the hood of this bedazzled gift box. The primary functions of the box are handled by an Arduino Nano; which runs the trivia game and provides user interaction via a 16×2 LCD, three push buttons, and a buzzer. Once the trivia game is complete, a servo is used to unlock the box and allow the recipient access to the physical gifts.

But that’s not the only trick this box has hidden inside. Once the main trivia game is complete, a ESP8266 kicks into action and advertises an access point the user can connect to. This starts the second level of challenges and gifts, which includes a code breaking challenge and gifted software licenses.

The project wasn’t all smooth sailing though. [Harrison] admits that his skills are still developing, and there were a few lessons learned during this project he is unlikely to forget in the future. Some Magic Smoke managed to escape when he connected his 5V Arduino directly to the 3.3V ESP8266, but at least it was a fairly cheap mistake and he had spares on hand to get the project completed anyway.

This project is reminiscent of reverse geocache boxes which only open when moved to a certain location, but the trivia aspect makes it perfect even for those of us who don’t want to put pants on just to receive our Internet gifts.

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Sonoff Factory Tour Is A Lesson On Life In Shenzhen

December 29, 2017 by 24 Comments

Judging by the popularity of “How It’s Made” and other shows of the genre, watching stuff being made is a real crowd pleaser. [Jonathan Oxer] from SuperHouse is not immune to the charms of a factory tour, so he went all the way to China to visit the factory where Sonoff IoT devices are made, and his video reveals a lot about the state of electronics manufacturing.

Test jig for six units at once

For those interested only in how Sonoff devices are manufactured, skip ahead to about the 7:30 mark. But fair warning — you’ll miss a fascinating discussion of how Shenzhen rose from a sleepy fishing village of 25,000 people to the booming electronics mecca of 25 million that it is today. With growth supercharged by its designation as a Special Economic Zone in the 1980s, Shenzhen is now home to thousands of electronics concerns, including ITEAD, the manufacturers of the Sonoff brand. [Jonathan]’s tour of Shenzhen includes a trip through the famed electronics markets where literally everything needed to build anything can be found.

At the ITEAD factory, [Jonathan] walks the Sonoff assembly line showing off an amazingly low-tech process. Aside from the army of pick and places robots and the reflow and wave soldering lines, Sonoff devices are basically handmade by a small army of workers. We lost count of the people working on final assembly, testing, and packaging, but suffice it to say that it’ll be a while before robots displace human workers in electronic assembly, at least in China.

We found [Jonathan]’s video fascinating and well worth watching. If you’re interested in Sonoff’s ESP8266 offerings, check out our coverage of reverse engineering them. Or, if Shenzhen is more your thing, [Akiba]’s whirlwind tour from the 2016 Superconference will get you started.

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Hunting Rogue Access Points With The ESP8266

December 28, 2017 by 32 Comments

Cantennas outperform every consumer-grade Wi-Fi antenna I’ve had the bad luck of purchasing. Cantenna is a mashup of ‘can’ and ‘antenna’ creating the nickname for a directional waveguide antenna built from re-purposed steel cans. For anyone who has yet to build one, it makes an excellent afternoon project. Here are some build instructions and technical details. I went beyond that, and ended up catching a rogue WiFi access point in the process.

When I needed to extend the range of some ESP8266-based sensors, cantennas were right at the top of my list of things to try. It was easy enough to build one, attach it to a Wemos Mini D1 Pro, and call the job done… leaving me with plenty of time to over-engineer it, and I ended up down a bit of a rabbit hole.

The first thing I did was stop using cans. Canned goods are not only expensive in my corner of the world, but more importantly don’t lend themselves that well to making a standardized antenna in volume. I can also only eat so many beans! The latter reason alone is enough to consider an alternative design like a modular dish reflector.

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The WiFi Repeater You Probably Have On Your Bench

December 25, 2017 by 29 Comments

Few things are as frustrating as a WiFi signal that drops in and out. On a public network it is bad enough but at home? Even if you can live with it, your cohabitants will certainly impune your technical abilities if they don’t have solid WiFi.  One solution is a WiFi repeater. You can buy one, of course. But you can also make one out of an ESP8266 and some code from GitHub. There is also a video about the project, below.

[Martin Ger’s] code implements NAT, so it isn’t a true WiFi repeater, but more of a bridge or router. Of course, that means performance isn’t stellar, but tests show it can sustain about 5 Mbps, which isn’t bad for a little board that costs a couple of bucks. There is a limit of 8 clients, but that’s more than enough for a lot of cases. Even if you don’t want to use it as a router, it has a mesh mode that could be a basis for some interesting projects all by itself.

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