Tune Into The Bonnaroo That No One Gets To Go To

August 9, 2020 by Kristina Panos 3 Comments

Just like everything else in 2020, the four-day, multi-stage festival of music and art known as Bonnaroo has been cancelled. This would have been [Guy Dupont]’s fifth year making the journey to Tennessee with his friend. Since they couldn’t go, [Guy] decided to build an interactive Bonnaroo mix tape into an 80s clock radio as a birthday present.

[Guy] was able to re-purpose all the original buttons and dials to navigate through the schedule of acts that would have performed across four days and five stages. The conveniently four-way function slider is used to choose the day, and the radio tuning dial selects the stage, complete with delightful static between the positions. The rest of the buttons move back and forth through the scheduled set times, and one will scroll the track and artist name across the 16-segment displays. The snooze button has the honor of being the play/pause button.

All the inputs are controlled with a Feather M4 express, and the music comes through a DFPlayer Mini. We love that [Guy] was able to repurpose the analog tuning dial by coupling it to a slide potentiometer that fit perfectly in a slot on the underside of the plastic. Stay tuned for a great video that starts with an explanation and demo and then goes into the build.

Though the utility of the clock radio may have been supplanted by cell phone alarms and doomscrolling, that just means that there are theoretically more of them to gut and turn into other things, like this Fallout-inspired luggable Pip-Boy.

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ESP32 Turned Open Source COVID-19 Contact Tracer

July 28, 2020 by Tom Nardi 17 Comments

Over the past few months we’ve heard a lot about contact tracers which are designed to inform users if they’ve potentially come into close proximity with someone who has the virus. Generally these systems have been based on smartphone applications, but there are also hardware solutions that can operate independently for those who are unable or unwilling to install the software. Which is precisely what [Tom Bensky] has implemented using an ESP32 and a USB battery bank.

The idea is simple: the software generates a unique ID which is broadcast out by the ESP32 over Bluetooth Low Energy. Appended to that ID is a code that indicates the person’s current physical condition. There’s no centralized database, each user is expected to update their device daily with any symptoms they may be experiencing. If your tracker is blinking, that means somebody has come in close enough proximity that you should look at the collected data and see how they were feeling at the time.

It’s not a perfect system, of course, as for one thing the number of people that are willing and able to flash this firmware onto a spare ESP32 and carry the thing around with them all day is going to be extremely small. This might have filled an interesting niche if we were still going to hacker and maker cons this summer, but all of those have gone virtual anyway. That said, it’s an interesting look at how a decentralized contact tracing system can be implemented cheaply and quickly.

Another detail worth taking a look at is how [Tom] handled the user experience in his firmware. In an effort to make the tracer as easy as possible to configure, he’s using the Web Bluetooth capability of Google Chrome. Just open up the local web page in your browser, and it will handle talking to the hardware for you. Even if you’re not in the market for a contract tracer, we think this is a great example for how to handle end-user configuration on the ESP32.

We’ve already looked at contact tracer APIs from Google and Apple, dedicated COVID-19 hardware tokens, and even other open source attempts at decentralized proximity tracking. It’s a lot to process, and everyone seems to have their own idea on how it should be done. In the end, the most practical solution is probably to just stay at home as much as possible.

Son Of Rothult

July 26, 2020 by Brian McEvoy 6 Comments

We are continuously inspired by our readers which is why we share what we love, and that inspiration flows both ways. [jetpilot305] connected a Rothult unit to the Arduino IDE in response to Ripping up a Rothult. Consider us flattered. There are several factors at play here. One, the Arduino banner covers a lot of programmable hardware, and it is a powerful tool in a hardware hacker’s belt. Two, someone saw a tool they wanted to control and made it happen. Three, it’s a piece of (minimal) security hardware, but who knows where that can scale. The secure is made accessible.

The Github upload instructions are illustrated, and you know we appreciate documentation. There are a couple of tables for the controller pins and header for your convenience. You will be compiling your sketch in Arduino’s IDE, but uploading through ST-Link across some wires you will have to solder. We are in advanced territory now, but keep this inspiration train going and drop us a tip to share something you make with this miniature deadbolt.

Locks and security are our bread and butter, so enjoy some physical key appreciation and digital lock love.

3D Printed ESP8266 TV Is A Blast From The Past

July 23, 2020 by Tom Nardi 16 Comments

We’ve often said that one of the best applications for desktop 3D printing is the production of custom enclosures, but you certainly aren’t limited to an extruded version of the classic Radio Shack project box. As [Marcello Milone] shows with this very clever retro TV enclosure for the Wemos D1 Mini, 3D printing means your imagination is the only limit when it comes to how you want to package up your latest creation.

As nice as the printed parts are, it’s the little details that really sell the look. [Marcello] has bent a piece of copper wire into a circle to make a faux antenna with vintage flair, and while the ESP is connecting to the WiFi network, it even shows an old school TV test pattern on its 1.8″ TFT display.

In the video after the break you can see the device go through its startup routine, and while displaying the Hackaday Wrencher at boot might not be strictly on theme…we’ll allow it.

While you could certainly use this little enclosure for whatever ESP project you had in mind, [Marcello] says he’s building a distributed environmental monitoring network using HTU21D temperature and humidity sensors. It sounds like he’s still working on the software side of things though, so hopefully he posts an update when the functionality is fully realized.

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Bluepill Copies Code So You Don’t Have To

July 17, 2020 by Al Williams 5 Comments

You really should learn to read Morse code. But if you can’t — or even if you can, and just want a break — you can always get a computer to do it. For example, [jmharvey1] has a decoder that runs on a cheap Bluepill dev board.

The device uses a touchscreen and a few common components. The whole thing cost about $16. You can see it at work along with a description of the project in the video below.

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Smooth(er) Text Scrolling On HD44780 LCDs

July 16, 2020 by Tom Nardi 14 Comments

Most Hackaday readers are likely to be familiar with character LCDs driven by the extremely common Hitachi HD44780 controller chip. If you’re looking for a cheap and easy way for your microcontroller project to display some data, they’re pretty much the go-to solution. But as popular as these displays are, there’s no denying that they’re starting to look a bit dated in 2020. Which is why the tweaks [Joseph Rautenbach] is working on are so interesting.

With one of these displays, the controller puts a single character on each 5×8 block of pixels. There’s also support for creating custom characters, which can be used for rudimentary icons. You’re pretty limited by the per-block resolution, but with a little imagination, you can usually get the point across. With a bit of dead space between each block of the display there’s little point in trying to make icons that “bridge” multiple blocks, as they’ll always be segmented.

But as [Joseph] realized, that’s less of a problem for scrolling text. So he wrote some code that takes an ASCII string and breaks it down into partial letters and numbers which can be displayed as custom characters. The controller only has space for 8 of these characters though, so the code needs to continually step through the string and generate the appropriate offset characters as the position of the text changes.

While the effect looks pretty good in the video after the break, [Joseph] has found that real-world utilization is a bit finicky. He tried the same code on one of the displays that uses white text on a blue background, and the scrolling text ended up ghosting together so it looked like gibberish. So while he’s released the source code for others to experiment with this trick, your mileage may vary.

This certainly isn’t the first time we’ve seen somebody make clever use of custom characters on the HD44780. We’ve seen it used for an exceptionally tiny game of Tetris, a rendition of Conway’s Game of Life, and even a horizontal space-shooter.

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Touch Screen Reflow Oven Pulls Out All The Stops

July 16, 2020 by Tom Nardi 17 Comments

We’ve seen plenty of simple reflow ovens, and there’s an excellent chance that some of the people reading these words have even thrown their own together. A minimal example isn’t much more than a old toaster oven, a Solid State Relay (SSR), a thermocouple, and a microcontroller to get them all talking. But if you’re like [Mangy_Dog] and willing to put in a bit more effort, the final result can be a capable piece of equipment that will be the envy of the hackerspace.

This build started as most do, with a search for a used toaster oven. But in the end he actually found a German model cheap enough that he could buy it new without going over budget for the project. Though he soon found out why: when it arrived, the so-called “pizza oven” was far smaller than he’d imagined. Luckily, it ended up being the perfect size for PCBs.

Unfortunately, the heating elements weren’t quite where he wanted them. Even after wrapping the heating chamber with ceramic insulation, a feature that was likely left off the original oven to cut costs, he says the temperature would only rise about 1 degree per second. So he added an additional halogen heating element at the top of the oven which pushed that rate up to 6 degrees per second.

Control is provided by an Arduino Pro Mini and a touch screen display with some very slick graphics. There’s the expected thermocouple to detect the current temperature, but while the earlier versions of the electronics used the aforementioned SSR to control the heating elements, [Mangy_Dog] eventually replaced it with a dimmer module rated for 4000 watts. After coming up with a circuit that allowed him to control the dimmer with the Arduino, this module gave for much finer control over the chamber temperature. Plus it apparently kept all the lights in his house from flickering when the elements kicked in at 100%, which was a nice bonus.

This isn’t the first time we’ve seen somebody shoehorn an LCD into an off-the-shelf toaster oven, but it’s certainly one of the most polished examples to ever come our way. When even commercially available units need some hacking to reach feature parity with DIY versions, building your own reflow oven still seems like the way to go in 2020.

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