TechyMagThings

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!

Over on YouTube [Andrew Neal] has a Function Generator Build for Beginners.

As beginner videos go this one is fairly comprehensive. [Andrew] shows us how to build a square-wave generator on a breadboard using a 555 timer, explaining how its internal flip-flop is controlled by added resistance and capacitance to become a relaxation oscillator. He shows how to couple a potentiometer to vary the frequency.

He then adds an integrator built from a TL082 dual op amp to convert the circuit to a triangle-wave generator, using its second op amp to build a binary inverter. He notes that a binary inverter is usually implemented with a comparator, but he uses the op amp because it was spare and could be put to good use. Again, potentiometers are added for frequency control, in this case a 1 MΩ pot for coarse control and a 10 kΩ pot for fine control. He ends with a challenge to the viewer: how can this circuit be modified to be a sine-wave generator? Sound off in the comments if you have some ideas!

If you’re interested to know more about function generators check out A Function Generator From The Past and Budget Brilliance: DHO800 Function Generator.

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.

Sometimes you have this project idea in your mind that seems so simple and straightforward, and which feels just so right that you have to roll with it. Then, years later you stumble across the sad remnants of the tearful saga and the dismal failure that it portrays. Do you put it away again, like an unpleasant memory, or write it up in an article, as a tearful confession of past sins? After some coaxing by a friend, [Alessandro] worked up the courage to detail how he set about making a hardware-only password keeper, and why it failed.

The idea was so simple: the device would pretend to be a keyboard and type the passwords for you. This is not that unusual, as hardware devices like the Mooltipass do something similar. Even better, it’d be constructed only out of parts lying around, including an ATtiny85 and an HD44780 display, with bit-banged USB connectivity.

Overcoming the challenge of driving the LC display with one pin on the MCU required adding a 74HC595 demultiplexer and careful timing, which sort of worked when the stars aligned just right. Good enough, but what about adding new passwords?

This is where things quickly skidded off the tracks in the most slapstick way possible, as [Alessandro] solved the problem of USB keyboard HID devices being technically ‘output-only’, by abusing the indicator statuses for Caps Lock, Num Lock, and Scroll Lock. By driving these from the host PC in just the right way you can use them as a sort of serial protocol. This incidentally turned out to be the most reliable part of the project.

Where the project finally tripped and fell down the proverbial flight of stairs was when it came to making the bit-banged USB work reliably. As it turns out, USB is very unforgiving with its timing unlike PS/2, making for an infuriating user experience. After tossing the prototype hardware into a box, this is where the project gathered dust for the past years.

If you want to give it a try yourself, maybe using an MCU that has more GPIO and perhaps even a USB hardware peripheral like the STM32F103, ESP32-S3 or something fruit-flavored, you can take a gander at the project files in the GitHub repository.

We’re always happy to see projects that (ab)use the Lock status indicators, it’s always been one of our favorite keyboard hacks.

If you want to play with the coolest kids on the block when it comes to photography, you have to shoot film. Or so say the people who shoot film, anyway. It is very true though that the chemical medium has its own quirks and needs a bit of effort in a way digital cameras don’t, so it can be a lot of fun to play with.

It’s expensive though — film ain’t cheap, and if you don’t develop yourself there’s an extra load of cash. What if you could get more photos on a roll? It’s something [Japhy Riddle] took to extremes, creating a fifth-frame 35mm camera in which each shot is a fifth the size of the full frame.

Standard 35mm still film has a 24x36mm frame, in modern terms not far off the size of a full-size SD card. A standard roll of film gives you 36 exposures. There are half-frame cameras that split that frame vertically to give 72 exposures, but what he’s done is make a quarter-frame camera.

It’s a simple enough hack, electrical tape masking the frame except for a vertical strip in the middle, but perhaps the most interesting part is how he winds the film along by a quarter frame. 35mm cameras have a take-up reel, you wind the film out of the cartridge bit by bit into it with each shot, and then rewind the whole lot back into the cartridge at the end. He’s wound the film into the take-up reel and it winding it back a quarter frame at a time using the rewind handle, for which we are guessing he also needs a means to cock the shutter that doesn’t involve the frame advance lever.

We like the hack, though we would be worried about adhesive tape anywhere near the shutter blind on an SLR camera. It delivers glorious widescreen at the cost of a bit of resolution, but as an experimental camera it’s in the best tradition. This is one to hack into an unloved 1970s snapshot camera for the Shitty Camera Challenge!

[Jer Schmidt] needed a way to put a lot of M8 bolts into a piece of square steel tubing, but just drilling and tapping threads into the thin steel wouldn’t be strong enough. So he figured out a way to reliably weld nuts to the inside of the tube, and his technique works even if the tube is long and the inside isn’t accessible.

Essentially, one drills a hole for the bolt, plus two smaller holes on either side. Then one welds the nut to the tubing through those small holes, in a sort of plug weld. A little grinding is all it takes to smooth out the surface, and one is left with a strong threaded hole in a thin-walled tube, using little more than hardware store fasteners.

The technique doesn’t require access to the inside of the tube for the welding part, although getting the nut back there in the first place does require a simple helper tool the nut can slot into. [Jer] makes one with some scrap wood and a table saw, just to show it doesn’t need to be anything fancy.

Another way to put a threaded hole into thin material is to use a rivnut, or rivet nut (sometimes also used to put durable threads into 3D prints) but welding a plain old nut to the inside was far more aligned with what [Jer] needed, and doesn’t rely on any specialty parts or tools.

[Jer]’s upcoming project requires a lot of bolts all the way down long tubing, which is what got him into all of this. Watch it in action in the video below, because [Jer] has definitely worked out the kinks, and he steps through a lot of tips and tricks to make the process painless.

Thanks [paulvdh] for the tip!

Simulator-style video games are designed to scale in complexity, allowing players to engage at anything from a casual level to highly detailed, realistic simulation. Microsoft Flight Simulator, for example, can be played with a keyboard and mouse, a controller, or a huge, expensive simulator designed to replicate a specific airplane in every detail. Driving simulators are similar, and [CNCDan] has been hard at work on his DIY immersive driving sim rig, with this hand brake as his latest addition.

For this build, [CNCDan] is going with a lever-style handbrake which is common in motorsports like drifting and rallying. He has already built a set of custom pedals, so this design borrows heavily from them. That means that the sensor is a load cell, which takes input force from a lever connected to it with a spring mechanism. The signal is sent to an Arduino for processing, which is set up to send data over USB like any joystick or controller. In this case, he’s using an Arduino that was already handling inputs from his custom shifter, so he only needed to use another input and add some code to get his handbrake added into his sim.

[CNCDan] built a version of this out of laser-cut metal parts, but also has a fully 3D printable one available as well. Plenty of his other videos about his driving rig are available as well, from the pedal assembly we mentioned earlier to the force-feedback steering wheel. It’s an impressive set of hardware with a feel that replicates racing about as faithfully as a simulator could. Interestingly, we’ve also seen this process in reverse as well where a real car was used instead as a video game controller.