Converting AC Irrigation Valves To DC Operation

February 9, 2026 by Lewin Day 19 Comments

Due to historical engineering decisions made many decades ago, a great many irrigation systems rely on solenoid valves that operate on 24 volts AC. This can be inconvenient if you’re trying to integrate those valves with a modern smart home control system. [Johan] had read that there were ways to convert these valves to more convenient DC operation, and dived into the task himself.

As [Johan] found, simply wiring these valves up to DC voltage doesn’t go well. You tend to have to lower the voltage to avoid overheating, since the inductance effect used to limit the AC current doesn’t work at DC. However, even at as low as 12 volts, you might still overheat the solenoids, or you might not have enough current to activate the solenoid properly.

The workaround involves wiring up a current limiting resistor with a large capacitor in parallel. When firing 12 volts down the line to a solenoid valve, the resistor acts as a current limiter, while the parallel cap is initially a short circuit. This allows a high current initially, that slowly tails off to the limited value as the capacitor reaches full charge. This ensures the solenoid valve switches hard as required, but keeps the current level lower over the long term to avoid overheating. According to [Johan], this allows running 24V AC solenoid valves with a 12V DC supply and some simple off-the-shelf relay boards.

We’ve seen similar work before, which was applied to great effect. Sometimes doing a little hack work on your own can net you great hardware to work with. If you’ve found your own way to irrigate your garden as cheaply and effectively as possible, don’t hesitate to notify the tipsline!

Habit Detection For Home Assistant

February 8, 2026 by Lewin Day 12 Comments

Computers are very good at doing exactly what they’re told. They’re still not very good at coming up with helpful suggestions of their own. They’re very much more about following instructions than using intuition; we still don’t have a digital version of Jeeves to aid our bumbling Wooster selves. [Sherrin] has developed something a little bit intelligent, though, in the form of a habit detector for use with Home Assistant.

In [Sherrin]’s smart home setup, there are lots of things that they wanted to fully automate, but they never got around to implementing proper automations in Home Assistant. Their wife also wanted to automate things without having to get into writing YAML directly. Thus, they implemented a sidecar which watches the actions taken in Home Assistant.

The resulting tool is named TaraHome. When it detects repetitive actions that happen with a certain regularity, it pops up and suggests automating the task. For example, if it detects lights always being dimmed when media is playing, or doors always being locked at night, it will ask if that task should be set to happen automatically and can whip up YAML to suit. The system is hosted on the local Home Assistant instance. It can be paired with an LLM to handle more complicated automations or specific requests, though this does require inviting cloud services into the equation.

We’ve featured lots of great Home Assistant hacks over the years, like this project that bridges 433 MHz gear to the smart home system. If you’ve found your own ways to make your DIY smart home more intelligent, don’t hesitate to notify the tipsline!

Upgrading The E-mu Audity 20 Years After Factory Support Ended

February 8, 2026 by Lewin Day 13 Comments

If you purchased an E-mu Audity 2000 ROMpler back in 1998, you almost certainly got a rig with the 1.00 firmware. It was fine, if a little limited, particularly where upgradability was concerned. E-mu would later offer firmware upgrades over MIDI with the 2.00 firmware, but to get the 2.00 firmware, you needed to ship the box back to E-mu. Or you did… until now.

Realizing that E-mu is long gone and they weren’t going to handle any further firmware upgrades, [Ray Bellis] set about finding another way to help aggrieved operators with gear stuck on v1.00. [Ray] had managed to lay hands on a Audity 2000 service manual as well as the official 2.00 upgrade kit in an estate sale, and set about reverse engineering it to help the community. It turned out that upgrading from 1.00 to 2.00 required the use of a special boot ROM and a flash device containing the upgraded firmware image. Booting from the special ROM required the use of a jumper, and when engaged, the ROM would copy the updated image to the device itself.

[Ray] didn’t want to duplicate the standard upgrade device, as that seemed a little difficult what with parts availability in 2026. Instead, he crafted his own ROM that, with compression, contained the necessary firmware upgrade image and could all be stuffed inside a single 512 KB chip. All you need to do is flash the custom upgrade ROM to an AM29F040B PLCC32 NOR flash chip, pop it in the empty PLCC32 socket on the mainboard, and away you go. This will get you a machine upgraded to the final v2.01 firmware delivered by E-mu before its demise.

It’s a finicky bit of work, but it’s a great way to get new functionality out of an old Audity 2000. We’ve featured similar work before regarding aging Yamaha synths, too. If you’ve got your own backdoor methods for giving older music hardware a new lease on life, don’t hesitate to notify the tipsline.

A Simple Desktop Pomodoro Timer

February 7, 2026 by Lewin Day 7 Comments

Pomodoro timers are a simple productivity tool. They help you work in dedicated chunks of time, usually 25 minutes in a sitting, before taking a short break and then beginning again. [Clovis Fritzen] built just such a timer of his own, and added a few bonus features to fill out its functionality.

The timer is based around the popular ESP32-S2 microcontroller, which has the benefit of onboard WiFi connectivity. This allows the project to query the Internet for things like time and date updates via NTP, as well as weather conditions, and the value of the Brazilian Real versus the American dollar. The microcontroller is paired with an SHT21 sensor for displaying temperature and humidity in the immediate environment, and an e-paper display for showing timer status and other relevant information. A button on top of the device allows cycling between 15, 30, 45, and 60 minute Pomodoro cycles, and there’s a buzzer to audibly call time. It’s all wrapped up in a cardboard housing that somehow pairs rather nicely with the e-paper display aesthetic.

If Pomodoro is your chosen method of productivity hacking, a project like this could suit you very well. We’ve featured a few similar builds before, too. Continue reading “A Simple Desktop Pomodoro Timer” →

Fidget Clicker Becomes Miniature Game Console

February 6, 2026 by Lewin Day 2 Comments

Fidget toys are everywhere these days. A particularly popular type simply puts some keyboard switches on a plate to provide a certain type of clicky satisfaction. [wjddnjsdnd] took that concept a step further, building a keychain-sized fidget toy that actually has games on it.

The build is based around six key switches in a 2 x 3 array. The key switches are notable in this case for being magnetic shaft keys. Rather than using a mechanical switch to indicate a keypress, the keycap instead merely moves a magnet which triggers a signal in a hall effect sensor beneath the key. In this case, the build uses A3144 hall effect sensors, which are read by the Arduino Nano running the show. The Nano is also hooked up to a small SSD1306 OLED display over I2c, which it uses for displaying the game state. There’s also a TP4056 module to handle charging the attached 380 mAh lithium-ion battery which powers the pocket-sized device.

The Arduino Nano is not a powerful platform for gaming, but it can handle the basics. The Gamebox Clicker, as it’s called, features a Pong clone, a stairs game, and a recreation of Snake. Think early mobile phone games, and you’d be on the money.

It’s an interesting build, and one that would be a great way to get used to using magnetic key switches as well as small embedded displays. We’ve seen Arduino boards turned into microconsoles many times before, too. If you’d like to sound off about magnetic vs. mechanical key switches, jump into the comments, or otherwise let us know about your best electronic fidget projects on the tipsline. Happy hacking.

The Weird Propeller That Offers Improved Agility On The Water

February 6, 2026 by Lewin Day 45 Comments

When it comes to seaborne propulsion, one simple layout has largely dominated over all others. You pair some kind of engine with some kind of basic propeller at the back of the ship, and then you throw on a rudder to handle the steering. This lets you push the ship forward, left, and right, and stopping is just a matter of turning the engine off and waiting… or reversing thrust if you’re really eager to slow down.

This basic system works for a grand majority of vessels out on the water. However, there is a more advanced design that offers not only forward propulsion, but also steering, all in the one package. It may look strange, but the Voith Schneider propeller offers some interesting benefits to watercraft looking for an edge in maneuverability.

Continue reading “The Weird Propeller That Offers Improved Agility On The Water” →

Getting The VIC-20 To Speak Again

February 5, 2026 by Lewin Day 9 Comments

The Commodore Amiga was famous for its characteristic Say voice, with its robotic enunciation being somewhat emblematic of the 16-bit era. The Commodore VIC-20 had no such capability out of the box, but [Mike] was able to get one talking with a little bit of work.

The project centers around the Adventureland cartridge, created by Scott Adams (but not the one you’re thinking of). It was a simple game that was able to deliver speech with the aid of the Votrax Type and Talk speech synthesizer box. Those aren’t exactly easy to come by, so [Mike] set about creating a modern equivalent. The concept was simple enough. An Arduino would be used to act as a go between the VIC-20’s slow serial port operating at 300 bps and the Speakjet and TTS256 chips which both preferred to talk at 9600 bps. The audio output of the Speakjet is then passed to an LM386 op-amp, set up as an amplifier to drive a small speaker. The lashed-together TTS system basically just reads out the text from the Adventureland game in an incredibly robotic voice. It’s relatively hard to understand and has poor cadence, but it does work – in much the same way as the original Type and Talk setup would have back in the day!

Text to speech tools have come a long way since the 1980s, particularly when it comes to sounding more natural. Video after the break.

Continue reading “Getting The VIC-20 To Speak Again” →