Laser soldering

Solder Stencil Done Three Ways

This project, sent in by [Henk], goes through a few different ways to make a solder stencil using a vinyl cutter, a CO2 laser, and a fiber laser.

The project starts with identifying a method to convert the board’s Gerber files to a PNG, which is ultimately used to create a vector file for use with the laser. The first stencil, made with the CO2 laser, was cut out of masking tape. This worked fine for larger cutouts and is certainly a cheap option if you don’t have too many small components. A slightly better approach with the CO2 laser was using vinyl sheet release paper, which seemed to hold together better than the tape.

Laser-cut masking tape works, but not for long.

A vinyl cutter was also used as an experiment, but it didn’t perform as well as the CO2 laser, as expected, since the cutter uses a knife rather than light, leading to some tearing issues.

The final method utilized a fiber laser and an empty drink can to create a metal stencil. First, the can had to be cut open, heated, and flattened. The fiber laser was able to cut clean footprints in the aluminum, creating a stencil that would hold up to more use than the paper variations.

The finale of this exploration into laser stencil making was using the fiber laser to solder the board together. The stencil was used to spread paste on the pads, parts were placed on the board, and then the fiber laser heated the solder paste to solder them to the board. The board looked a bit toasty afterwards, but we imagine the process could be fine-tuned to reduce the collateral damage a bit.

Once you’ve got your stencil ready to go, you can combine it with a 3D printed jig to hold the PCB while you apply the solder paste.

Air Fryer rPi upgrade

From Burnt To Brilliant: A Toaster’s Makeover

Appliances fail, but that doesn’t mean it’s the end for them. This impressive hack from [solopilot] shows the results possible when not just fixing but also improving upon its original form. The toaster’s failed function selector switch presented an opportunity to add smart features to the function selection and refine control over its various settings.

Before upgrading the toaster, [solopilot] first had to access its components, which is no trivial task with many modern appliances. Photos document his process of diving into the toaster, exposing all the internals to enable the upgrade. Once everything was accessible, some reverse engineering was required to understand how the failed function selector controlled the half-dozen devices it was wired to.

Toaster App GuiNext came the plan for the upgrades—a long list that included precise temperature control and the ability to send an SMS showing the state of your meal. A Raspberry Pi Zero, a solid-state relay, a relay control board, and a thermocouple were added to the toaster, unlocking far more capability and control than it had originally. Some tuning is required to fully enable these new features and to dial in the precision this once run-of-the-mill toaster is now capable of.

The work wasn’t limited to the toaster itself. [solopilot] also seized the opportunity to create an Android app with speech recognition to control his now one-of-a-kind Cuisinart. It’s probably safe to say his TOA-60 is currently the smartest toaster in the world. If you check out his documentation, you’ll find all the pinouts, circuits, code, and logic explanations needed to add serious improvements to your own toaster. We’ve featured several other toaster oven projects over the years, most of which have focused on turning them into reflow ovens, so it’s exciting to see one aimed at improving upon its original design.

 

 

Fytó pet plant

2025 Pet Hacks Contest: Fytó – Turn Your Plant Into A Pet

This entry into the 2025 Pet Hacks Contest is about bringing some fun feedback to normally silent plants. Fytó integrates sensors and displays into a 3D printed planter. The sensors read the various environmental and soil conditions that the plant is experiencing, and give you feedback about them via a series of playful expressive faces that are displayed on the screen embedded in the planter.

At the core of the Fytó is a Raspberry Pi Zero 2 W, which has plenty of power to display the animations while also being small enough to easily fit inside the planter without it growing in size much more than a normal planter would be. The sensors include a capacitive soil moisture sensor, a temperature sensor, and a light-dependent resistor. These sensors all provide analog outputs to relay their measurements and so there was an ADS1115 analog-to-digital converter board also included as the Raspberry Pi doesn’t have the required analog pins to communicate with them.

The fun animated faces are displayed with a 2-inch LCD display embedded in the planter. A small acrylic cover is placed in front of the LCD to help ease the transition from the printed planter to the internally mounted screen. The temperature and light sensors were also placed in openings around the planter to ensure they could get good environmental readings. There are six expressions the Fytó can express based on its sensor readings, ranging from happy when all the readings are in a good zone, to thirsty if it needs water or freezing when it’s too cold. Be sure to check out the other entries in the 2025 Pet Hacks Contest.

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Window Shade Motor

Automated Blinds Opener On The Cheap

We love seeing hacks that involve salvaging parts from what you have on hand to make a new project work, and this project is a great example of that. [Simon], in a quick weekend build, created an automated blinds opener using parts he had available.

The project began with the desire to have his blinds open slowly and silently, gradually letting in more light. To accomplish this, a few key components were needed, including a motor with a gearbox to provide the torque required to actuate the blinds and a magnetic encoder to track their progress. To isolate vibrations and keep the system silent, the motor is mounted using a silicone motor mount that he salvaged from a broken water flosser.

The printed holder for the magnetic encoder is a nice touch.

To mount the motor to the wall near the window, he used some 3D printed parts. A clever combination of surgical silicone tubing and silicone tape attaches the motor to the window blind shaft while limiting vibration transfer, keeping things quiet. [Simon] advises against using magnetic encoders as he did, noting that while he had them on hand and made them work, the magnetic shaft’s misalignment with the encoders makes it a less-than-ideal approach. Nevertheless, he got it working.

Automating blinds is a fairly common project around these parts, made all the more accessible with clever 3D printed mechanisms. We’ve even seen variations that can be used in rentals, dorms, and other places were permanent modifications need to be avoided.

Aquassist fish feeder

2025 Pet Hacks Contest: Aquassist Fish Feeder

This project submitted to the 2025 Pet Hacks Contest brings a bit of IoT to your finned friends. Aquassist is a fish feeder that is primarily 3D printed only requiring a servo and a microcontroller to give you remote control of feeding your fish.

The Aquassist consists of just six 3D-printed parts. At its core is an Archimedes screw, a mechanism that ensures consistent portions of fish food are dispensed into the fish tank. A small hopper on top holds the food, and to minimize the part count, all 3D-printed components are designed to be glued together.

The brains of the operation take place in a Wemos D1 mini, a compact ESP8266 board programed using the Arduino IDE. The feeding mechanism relies on an SG90 continuous rotation servo, which rotates the Archimedes screw to dispense food. Unlike standard servos, this model offers ample torque in a small package and can rotate continuously without hitting an angular limit.

The Aquassist is controlled via a web-based application accessible from any device. The D1 Mini connects to Firebase to check the feeding schedule or detect if the “Feed Now” button has been pressed. Users can set feeding times or trigger an immediate feeding through the app’s intuitive interface. Check out a video below to see the Aquassist in action, and check our our other entries into the 2025 Pet Hacks Contest.

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flipper zero uv sensor

A UV Meter For The Flipper Zero

We all know UV radiation for its contributions to getting sunburned after a long day outside, but were you aware there are several types different types of UV rays at play? [Michael] has come up with a Flipper Zero add on board and app to measure these three types of radiation, and explained some of the nuances he learned about measuring UV along the way.

At the heart of this project is an AS7331 sensor, it can measure the UV-A, UV-B, and UV-C radiation values that the Flipper Zero reads via I2C. While first using this chip he realized to read these values is more complex than just querying the right register, and by the end of this project he’d written his own AS7331 library to help retrieve these values. There was also a some experimenting with different GUI designs for the app, the Flipper Zero screen is only 128x64px and he had a lot of data to display. One feature we really enjoyed was the addition of the wiring guide to the app, if you install this Flipper Zero app and have just the AS7331 sensor on hand you’ll know how to hook it up. However if you want he also has provided the design files for a PCB that just plugs into the top of the Flipper Zero.

Head over to his site to check out all the details of this Flipper Zero project, and to learn more about the different types of UV radiation. Also be sure to let us know about any of your Flipper Zero projects.

Dollar bill validator

Reading The Color Of Money

Ever wondered what happens when you insert a bill into a vending machine? [Janne] is back with his latest project: reverse engineering a banknote validator. Curious about how these common devices work, he searched for information but found few resources explaining their operation.

To learn more, [Janne] explored the security features that protect banknotes from counterfeiting. These can include microprinting, UV and IR inks, holograms, color-shifting coatings, watermarks, magnetic stripes, and specialty paper. These features not only deter fraud but also enable validators to quickly verify a bill’s authenticity.

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