A nixie tube next to a screenshot of a to-do list

Nixie Tube Indicator Tells You How Many Tasks You’ve Got Left To Do

November 17, 2021 by Robin Kearey 10 Comments

For busy people, keeping track of all the tasks on your to-do list can be a daunting task in itself. Luckily there’s software to help you keep organized, but it’s always nice to have a physical artifact as well. Inspired by some beautiful nixie clock designs, [Bertrand Fan] decided to build a nixie indicator that tells him how many open items are on his to-do list, giving a shot of instant gratification as it counts down with each finished task.

The task-management part of this project is a on-line tool called Todoist. This program comes with a useful Web API that allows you to connect it your own software projects and exchange data. [Bert] wrote some code to extract the number of outstanding tasks from his to-do list and send it to an ESP8266 D1 Mini that drives the nixie tube. Mindful of the security implications of letting such a device connect directly to the internet, he set up a Mac Mini to act as a gateway, connecting to the ESP8266 through WiFi and to the Todoist servers through a VPN.

The little ESP board is sitting in a 3D-printed case, together with the nixie driver circuits and a socket to hold the tube. A ceramic tile glued to the front gives it a bit more of a sturdy, luxury feel to match the shiny glass and metal display device. The limitations of the nixie tube restrict the number of tasks indicated to nine, but we imagine this might actually be useful to help prevent [Bert] from overloading himself with too many tasks. After all, what’s the point of having this device if you can’t reach that satisfying “zero” at the end of the day?

Although nowadays nixie tubes are mostly associated with fancy clocks, we’ve seen them used in a variety of other uses, such as keeping track of 3D-printer filament, adding a display to a 1940s radio, or simply displaying nothing useful at all.

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Arduino Library Makes Digital Rain Like It’s 1999

November 17, 2021 by Tom Nardi 31 Comments

There’s going to be a new Matrix movie in theaters next month, and you know what that means: we’re about to see a whole new generation get obsessed with the franchise’s iconic “Digital Rain” effect. Thanks to modern advertisement technology, expect to see lines of glittering text pouring down the displays of everything from billboards to gas pumps pretty soon.

For those of us who’ve just been looking for an excuse to break out the old Matrix screensavers, you might as well get a jump on things using this handy Arduino library for the ESP8266 and ESP32. Developed by [Eric Nam], it lets you start up a digital rainstorm on displays supported by the TFT_eSPI library as easily as running digitalRainAnim.loop().

You can even install the library through the Arduino IDE, just open the Library Manager and search for “Digital Rain” to get started. You’ve still got to hook the display up to your microcontroller, but come on, [Eric] can’t do it all for you.

Looking at the examples, it seems like various aspects of the animation like color and speed can be configured by initializing the library with different values. Unfortunately we’re not seeing much in the way of documentation for this project, but by comparing the different examples, you should be able to get the high points.

While our first choice would certainly be a wall of green alphanumeric LED displays, we can’t help but be impressed with how easy this project makes it to spin up your own little slice of the Matrix on the workbench.

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Liberating The ESP8266 From Its Development Board

November 3, 2021 by Tom Nardi 14 Comments

While the ESP32 is clearly a superior piece of hardware, we think you’ll agree that the ESP8266 is just too useful not to have a dozen or so kicking around the parts bin at any given time. Cheap, easy to use, and just enough capabilities to bring your projects into the wonderful world of IoT. But if you really want to get the most out of it, you’ll eventually have to skip the development board and start working with the bare module itself.

It can be a scary transition, but luckily, [Ray] has collected some notes that should prove helpful for anyone looking use modules like the ESP-12F in their own custom PCBs. From different tips on making sure the power-hungry modules get enough juice, to cost cutting measures that help reduce the ancillary parts needed in your circuit design, it’s a worthwhile read for new and experienced ESP8266 wranglers alike.

For example, [Ray] talks a bit about using the infamous GPIO10 pin. This pin is on the rear of the ESP8266 module, and on many development boards, it isn’t even connected. That’s because its internally hooked up to the ESP8266’s SPI flash chip, and using it can cause problems if you’re not careful. But as explained in the blog post, as long as you make sure the flash mode is set to “dual IO” (DIO), then GPIO10 can be used just like any other free pin.

We also really liked the tip [Ray] shares at the end for making your boards more easily programmable. Sure you can leave an unpopulated header on the board, or fiddle with some pogo pin setup, but his edge connector approach is quite clever. Just slip the programmer on for the initial burn, and then after that you can update over the air.

There’s no denying how easy it is to throw something together with an ESP8266 development board, but we’ve covered so many incredible projects that have made use of the bare module’s diminutive dimensions that you’ll ultimately be missing out if you don’t cut out the middle-man.

Classic 80s Text-To-Speech On Classic 80s Hardware

October 26, 2021 by Bryan Cockfield 34 Comments

Those of us who were around in the late 70s and into the 80s might remember the Speak & Spell, a children’s toy with a remarkable text-to-speech synthesizer. While it sounds dated by today’s standards, it was revolutionary for the time and was riding a wave of text-to-speech functionality that was starting to arrive to various computers of the era. While a lot of them used dedicated hardware to perform the speech synthesis, some computers were powerful enough to do this in software, but others were not quite able. The VIC-20 was one of the latter, but thanks to an ESP8266 it has been retroactively given this function.

This project comes to us from [Jan Derogee], a connoisseur of this retrocomputer, and builds on the work by [Earle F. Philhower] who ported the retro speech synthesis software known as SAM from assembly to C which made it possible to run on the ESP8266. Audio playback is handled on the I2S port, but some work needed to be done to get this to work smoothly since this port also handles the communication with the VIC-20. Once this was sorted out, a patch was made to be able to hear the computer’s audio as well as the speech synthesizer’s. Finally, a serial command interface was designed by [Jan] which allows for control of the module.

While not many of us have VIC-20s sitting at home, it’s still an interesting project that shows the broad scope of a small and inexpensive chip like the ESP8266 which would have had a hefty price tag back in the 1980s. If you have other 80s hardware laying around waiting to be put to work, though, take a look at this project which brings new vocabulary words to that old classic Speak & Spell.

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The Wireless PS/2 Keyboard That Never Was

October 16, 2021 by Dan Maloney 11 Comments

The PS/2-style port was once about as ubiquitous on PCs as USB connectors are today, and more than a few of us accumulated a fair collection of keyboards and mice that sported the 6-pin mini-DIN plug. They’re not nearly as common today, but when you need one, you need one, so if your stockpile of PS/2 keyboards has dwindled to nothing, you might want to look at rolling your own PS/2 remote keyboard dongle.

That backstory on [Remy Sharp]’s build starts with his acquisition of a neptUNO, a 160€ FPGA retrocomputer that gives you access to just about every Z80 and 6502 computer of yesteryear. While the box supports USB keyboards, [Remy] had trouble getting one to work. So out came a Wemos D1 Mini, which was wired up to a stub of PS/2 cable. The microcontroller is powered by the PS/2 port, and connects to the WiFi network on boot-up and starts a WebSocket server. It also served up a page of HTML, which lets him connect with any device and send keystrokes to the neptUNO. He also added a couple of hardware buttons to the dongle, to access menus on the neptUNO directly. The video below shows it in action.

Perhaps unsurprisingly, [Remy] says he took inspiration for this build from [Ben Eater]’s excellent PS/2 deep dive. We’d like to think he saw that here first, but either way, it’s a valuable reference on how keyboards used to work.

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Hack Your Sodastream With A Giant CO2 Canister

October 14, 2021 by Lewin Day 110 Comments

Sodastream machines are popular amongst people who like to make their own seltzer water at home. However, replenishing the tiny gas canisters is expensive and wasteful. [Becky] decided to upgrade her machine to avoid this problem, and added some smarts while she was at it.

The simple part of the hack is using an adapter to connect the Sodastream apparatus to a 50 lb CO2 tank from the welding store. This is easy enough, and just uses a off the shelf adapter. Using welding-grade gas in your drinking water is probably a really bad idea, but [Becky] was willing to take the nisk.

However, safety was given due attention in that a CO2 monitor was installed to make [Becky] aware of any dangerous leaks. The tank is also placed on a custom scale built with load cells and an ESP8266, which allows monitoring of how much gas is left. [Becky] notes that at her rate of drinking one bottle a day, the tank should last her a full 7 years or so.

The project brings costs down to 18 cents per liter of seltzer, versus 38 cents for the Sodastream gas supply. It’s likely that the Sodastream prices could still be beat even if a food-safe CO2 source was used. Plus, there’s no need to regularly buy new bottles!

Overall, it’s a great project and one that recalls us of continuous-ink printer hacks. Video after the break.

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Picture of the automatic blind controller and three servo motors, all in their enclosures, displayed on a table.

Automated Window Blinds Using MQTT And Home Assistant

September 26, 2021 by Chris Lott 14 Comments

Finnish software engineer [Toni] is on a quest to modernize his 1991 house, and his latest project was to automate the window blinds and control them using Home Assistant. Unless your blinds have built-in motors, most of the effort of such a project centers around how to integrate and attach the motor — and as [Toni] points out, there are tons of different blinds with all kinds of operating mechanisms. But once you solve that issue, half the battle is over.

These particular blinds require less than one turn of the control rod to go from fully open to fully closed, and [Toni] selects a 270-degree range-of-motion, 20 kg*cm torque servo motor to drive them. He really wanted to install the motor inside the window, but it just wouldn’t fit. Instead, each servo motor is mounted in a custom 3D-printed case installed on the window frame just below the operating rod. An ESP8266-based controller box is installed above the window, hidden behind curtains, and operates all three servos.

On the software side of things, the project is coded in C++ and uploaded using the Ardiono IDE. The blinds communicate to [Toni]’s Home Assistant network using MQTT. All the software is available on the project’s GitHub repository, and the 3D-printed case design is posted on Thingiverse. Even though your blinds may be of a completely different design, we think many parts of [Toni]’s project are still useful — do check out this project if you’re thinking about doing something similar. The notion of motorized window blinds has been around for a some time — we covered one project way back in 2013 and another in 2016. If you have added automation to your window blinds, let us know how it went down in the comments section.

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