Simple ESP8266 Weather Station Using Blynk

Today’s hacker finds themself in a very interesting moment in time. The availability of powerful microcontrollers and standardized sensor modules is such that assembling the hardware for something like an Internet-connected environmental monitor is about as complex as building with LEGO. Hardware has become elementary in many cases, leaving software as the weak link. It’s easy to build the sensor node to collect the data, but how do you display it in a useful and appealing way?

This simple indoor temperature and humidity sensor put together by [Shyam Ravi] shows one possible solution to the problem using Blynk. In the video after the break, he first walks you through wiring the demonstration hardware, and then moves on to creating the Blynk interface. While it might not be the ideal solution for all applications, it does show you how quickly you can go from a handful of components on the bench to displaying useful data.

In addition to the NodeMCU board, [Shyam] adds a DHT11 sensor and SSD1306 OLED display. He’s provided a wiring diagram in the repository along with the Arduino code for the ESP8266, but the hardware side of this demonstration really isn’t that important. You could omit the OLED or switch over to something like a BME280 sensor if you wanted to. The real trick is in the software.

For readers who haven’t played with it before, Blynk is a service that allows you to create GUIs to interact with microcontrollers from anywhere in the world. The code provided by [Shyam] reads the humidity and temperature data from the DHT11 sensor, and “writes” it to the Blynk service. From within the application, you can then visualize that data in a number of ways using the simple drag-and-drop interface.

We’ve seen Blynk and ESP8266 used to control everything from mood lighting to clearance-rack robotic toys. It’s a powerful combination, and something to keep in mind next time you need to knock something together in short order.

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Rewinding Live Radio

Even though it’s now a forgotten afterthought in the history of broadcasting technology, we often forget how innovative the TiVo was. All this set-top box did was connect a hard drive to a cable box, but the power was incredible: you could pause live TV. You could record shows. You could rewind TV. It was an incredible capability, that no one had ever seen before. Of course, between Amazon and Netflix and YouTube, no one watches TV anymore, and all those platforms have a pause button, but the TiVO was awesome.

There is one bit of broadcasting that still exists. Radio. For his Hackaday Prize entry, [MagicWolfi] is bringing the set-top box to radio. He’s invented the Radio Rewind Button, and it does exactly what you would expect: it rewinds live radio a few minutes.

To have a pause or rewind button on a TV or radio, the only real requirement is a bunch of memory. The TiVO did this with a hard drive, and [MagicWolfi] is doing this with 256 MB of SDRAM. That means he needs to access a ton of RAM, and for that he’s turning to the Digilent ARTY S7 board. Yes, it’s an FPGA, but actually a fairly simple solution to the problem.

The rest of the circuit is an FM receiver chip and an I2S audio codec on an Arduino-shaped daughterboard. The main controller for this project is a big red button that will simply rewind the audio stream a few minutes. There’s no telling exactly how long [MagicWolfi] will be able to rewind the audio stream, but 256 MB is a ton in the audio world.

The Forgotten Art Of Riveted Structures

If you are in the habit of seeking out abandoned railways, you may have stood in the shadow of more than one Victorian iron bridge. Massive in construction, these structures have proved to be extremely robust, with many of them still in excellent condition even after years of neglect.

A handsome riveted railway bridge, over the River Avon near Stratford-upon-Avon, UK.
A handsome riveted railway bridge, over the River Avon near Stratford-upon-Avon, UK.

When you examine them closely, an immediate difference emerges between them and any modern counterparts, unlike almost all similar metalwork created today they contain no welded joints. Arc welders like reliable electrical supplies were many decades away when they were constructed, so instead they are held together with hundreds of massive rivets. They would have been prefabricated in sections and transported to the site, where they would have been assembled by a riveting gang with a portable forge.

 

So for an audience in 2018, what is a rivet? If you’ve immediately thought of a pop rivet then it shares the function of joining two sheets of material by pulling them tightly together, but differs completely in its construction. These rivets start life as pieces of steel bar formed into pins with one end formed into a mushroom-style dome, probably in a hot drop-forging process.

A rivet is heated to red-hot, then placed through pre-aligned holes in the sheets to be joined, and its straight end is hammered to a mushroom shape to match the domed end. The rivet then cools down and contracts, putting it under tension and drawing the two sheets together very tightly. Tightly enough in fact that it can form a seal against water or high-pressure steam, as shown by iron rivets being used in the construction of ships, or high-pressure boilers. How is this possible? Let’s take a look!

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Badgelife, The Hardware Demoscene Documentary

Last week, tens of thousands of people headed home from Vegas, fresh out of this year’s DEF CON. This was a great year for DEF CON, especially when it comes to hardware. This was the year independent badges took over, thanks to a small community of people dedicated to creating small-run hardware, puzzles, and PCB art for thousands of conference-goers. This is badgelife, a demoscene of hardware, and this is just the beginning. It’s only going to get bigger from here on out.

We were lucky enough to sit down with a few of the creators behind the badges of this year’s DEF CON and the interviews were fantastic. Right here is a lesson on electronic design, manufacturing, and logistics. If you’ve ever wanted to be an engineer that ships a product instead of a lowly maker that ships a product, this is the greatest classroom in the world.

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Installing LibreBoot The (Very) Lazy Way

Recently I was given a somewhat crusty looking ThinkPad T400 that seemed like it would make a good knock around machine to have on the bench, if it wasn’t for the fact the person who gave it to me had forgotten (or perhaps never knew) the BIOS password. Cleaning the machine up, putting more RAM in it, and swapping the wheezing hard drive for an SSD would be a relatively cheap way to wring a few more years of life from the machine, but not if I couldn’t change the boot order in BIOS.

Alright, that’s not entirely true. I could have installed an OS on the SSD from my desktop and then put it into the T400, but there was something else at play. The locked BIOS gave me the perfect excuse to install LibreBoot on it, which is one of those projects I’ve had in the back of my mind for years now. Replacing the BIOS with something entirely different would solve the password issue, but there was only one problem: the instructions for flashing LibreBoot onto the T400 are intimidating to say the least.

You’re supposed to take the entire machine apart, down to pulling the CPU cooler off and removing the display. All so you can flip the motherboard over to access a flash chip between the CPU and RAM that’s normally covered by a piece of the laptop’s frame. Oh how I hated that diabolical chunk of magnesium which kept me from my silicon quarry. Flashing the chip would take a few minutes, but YouTube videos and first hand accounts from forums told me it could take hours to disassemble the computer and then put it back together after the fact.

Deep into that darkness I peered, long I stood there, wondering, fearing, doubting. Then a thought came to me: maybe I could just cut the thing. If it was a success, it would save me hours of work. If it failed, well, at least the computer didn’t cost me anything. Time to roll the dice.

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Build A Fun CPU In Your Browser

A rite of passage for a digital designer is to build a CPU. That may seem a formidable task and if you are thinking of building a modern CPU like the one in your PC, it is. However, a simple CPU is well within the reach of anyone who can sling some logic gates or HDL. We’ve even seen CPUs built in Minecraft. Now you can play nandgame and build a CPU step-by-step in your browser.

The game is based on the popular From NAND to Tetris site. True to the name you start out with a single NAND gate as a tool. From there you build an inverter, an AND gate, adders, flip flops, registers, and the like. You get a little help from the accompanying text and there are some blacked out hints if you get stuck.

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An Upcycled Speaker Box With Hidden Features

At first glance, this fire engine red speaker box built by [NoshBar] looks straightforward enough. Just an MDF case and couple of drivers recovered from a trashed stereo. But the array of controls and connectors on the front, and a peek on the inside, shows there’s more to this particular project than meets the eye.

Built almost entirely from parts [NoshBar] found in the trash, construction started with some salvaged MDF IKEA shelves and their corresponding twist lock cam fittings. We don’t usually see those style cam fittings used to build DIY enclosures, but if it works for all those furniture manufacturers why not?

A pair of Sony stereo speakers he found gave up their internals, and a TPA3116 amplifier board off of eBay drives them. He’s wired up an audio pass-through mode for using headphones when the amplifier is powered off, and dual inputs so he can switch between PC and PS4.

But the audio components are only half of what’s inside that shiny red exterior. [NoshBar] packed in an ATX PSU and broke out the 3.3 V, 5 V, and 12 V lines to the front panel so he can use it as a bench power supply for his Arduino projects. It’s also home to a gigabit Ethernet switch and a Raspberry Pi acting as a file server.

We’re always amazed at what hackers are able to accomplish with parts they’ve literally pulled out of the trash, from a waterwheel to charge your phone to a functional CNC router. It seems there’s plenty of treasure in your local dumpster if you’re willing to get a little dirty.