Author: Matt Varian

80 Articles

Lightcomposer

LightComposer – Reach Out And Touch Your Lighting

June 22, 2026 by 3 Comments

While there is a time and place for wirelessly controlled devices, sometimes you want something you can just reach out and touch to interact with, no apps to install or devices to configure. In this case [John] wanted a lamp that was just that. Drawing inspiration from the rotary phone, he created the LightComposer.

This small lamp, just a bit smaller than a hockey puck, uses a 3D printed enclosure and a straightforward PCB. It’s a very accessible project to recreate. The 3D prints are well thought out including a TPU ring on the bottom to keep the lamp from sliding around. The light source comes from 32 SK6812 LEDs, which are very similar to NeoPixels. An ATmega328P microcontroller powers the project and can easily be programmed using the Arduino IDE. A rotary encoder in the center, coupled to the top diffuser, lets you control LED brightness and color by turning it. The firmware also includes some fun hidden light-effect modes.

Head over to [John]’s site for all the files needed to make your own LightComposer, or links to buy a premade one. What devices have you made that use a straightforward physical user interface in lieu of an app? Be sure to check some of the other lamp builds we’ve featured before.

SDS-Remote

SDS-Remote Brings Power-User Features To Siglent Scope

June 22, 2026 by 3 Comments

Many oscilloscopes have provisions to be connected to a computer and used remotely, but most of those interfaces are fairly rudimentary. To address this, [Winfried] has developed the SDS-Remote, a remote interface for the Siglent SDS 1000X-E series oscilloscopes.

The 1000X-E series oscilloscopes have both USB and network interfaces, and the SDS-Remote can use either (though the USB interface is still somewhat experimental). SDS-Remote allows for remote controlling the oscilloscope, capturing waveforms super handy as it lets you export a CSV file of the waveforms for further analysis. You can also capture screenshots of the scope through the web interface, making it much easier to compare waveforms as you’re working on a project. The built-in data logging lets you run long experiments and save out their results. The macro recorder lets you automate complex tests using SCPI commands and brings basic scripting to the interface without needing to run separate code. There’s also a mechanism to integrate an AI LLM to help translate common language into the correct scope configuration.

Thanks [Winfried] for sharing this awesome web interface for the oscilloscope no doubt it’ll be a welcome upgrade for those already remote controlling their Siglent scope. Head over to his GitHub page and check it out for yourself! Have you written any improved user interfaces for your equipment? Be sure to let us know what you’ve done so we can share with others who may find use in an interface that offers more than came with the product.

Continue reading “SDS-Remote Brings Power-User Features To Siglent Scope” →

RS-485 Sprinkler system

RS-485 Sprinkler Control: Scaling Irrigation Across The Farm

May 14, 2026 by 12 Comments
Building your own sprinkler system controller isn’t that difficult on the face of it, but what happens when your system starts to grow, adding more distant areas? To tackle this, [Vinnie] leveraged the tried-and-true RS-485 differential pairs to communicate reliably with ever-more-spread-out valves on his farm’s irrigation system.

The system uses a Raspberry Pi to control when each valve turns on and for how long. It does this via a custom RS-485 valve master board, whose code and design files are on GitHub. The master board communicates with the Pi over I2C and issues RS-485 commands while controlling the 12V line to the valves. Toggling the 12V supply is a smart move it lets [Vinnie] save power by not keeping the valves energized when idle.

At the valves themselves lives a valve node board (also on the GitHub repo). Each node has a unique address so it knows when its name is called to open or close a valve. The valves are latching solenoids, ideal because they don’t require constant current during the watering cycle. The Valve Nodes also support their own protocol to report state, firmware version, and allow in-situ configuration.

Be sure to head over to [Vinnie]’s project page and check out all the work that went into this great DIY irrigation control system, along with the thoughtful boards and tools he made to help others set it up. This is a welcome addition to the sprinkler-related projects we’ve seen.

SolMate Charger

2026 Green Powered Challenge: SolMate Charges On The Move

April 17, 2026 by 6 Comments

We’ve all had those times when your electrical device of choice is running low on battery. Sometimes you even plan ahead and are also carrying a battery pack, but what happens when you’ve forgotten to charge the battery pack? This is the problem that [Arnov Sharma] addressed with the SolMate, a portable solar panel that keeps a battery bank topped up.

The SolMate is built around an efficient 2 W photovoltaic panel that’s not much bigger than a cellphone. This panel can supply 5 V at 400 mA on a sunny day. The solar output is more than enough to keep the internal 2000 mAh battery topped up and ready for use. Charging the Li-ion battery is handled by an IP5306 power management chip, which pulls double duty: it safely regulates charging while boosting the battery’s 3.7 V to the 5 V expected at the USB charge ports. Speaking of charge ports, the SolMate includes both a USB-A and a USB-C port, plus a switch to enable or disable the unit.

The case is all 3D printed, with some clever design choices. Offsetting the bulk of the battery and PCB storage area to one side lets the SolMate naturally cant toward the sun. Even the clip used to attach it to a backpack is printed.

Be sure to check out the other entries into our latest challenge!

2026 Hackaday Green Powered Challenge
Open-Source eink firmware

Pocket-Sized E-Ink Gets A Firmware Upgrade

April 5, 2026 by 26 Comments

Not so long ago, e-ink devices were rare and fairly pricey. As they have become more common and cheaper, some cool form-factor devices have emerged that suffer from subpar software. [Concretedog] picked up just such a device, and that purchase led to the discovery of a cool open-source firmware project for this tiny gadget.

[Concretedog] described the process of loading the firmware, which is just about as easy a modification as one can make. You plug the e-ink display into your computer, visit a website, and can flash it right from there. Once the display is running the CrossPoint Reader firmware, it unlocks some new tricks on this affordable reader. The firmware lets you turn the device into a WiFi hotspot and upload books wirelessly, or it can connect to an existing network to add files that way. It also enables rotating the display and KOReader syncing if you have multiple devices you read from.

We love seeing the community step in and improve devices that are hardware-wise good, sometimes great, but come up lacking in the software or firmware department. Thanks [Concretedog] for sharing your experience with this device and the cool open-source firmware. Be sure to check out some other projects we’ve featured where a firmware swap breathed new life into the hardware.

macro photo slider

Tiny Moves, Big Depth: An Open-Source Macro Focus Slider

April 5, 2026 by 8 Comments

When taking macro photographs, you often need just a tiny bit of controlled motion — so little that it’s tough to pull off by hand. To address this, [Salveo] designed a small open-source macro photography slider featuring an anti-backlash handle.

Macro photography gives you an extremely shallow field of view, sometimes under 1 mm of depth, in which subjects stay in focus. To combat this, it’s common to capture multiple images while sliding the camera forward or backward, then combine them for a much larger depth of field than a single shot provides. [Salveo]’s slider gives fine control over this focus-stacking process, with the knob even marked to show every 1 mm of linear travel.

The slider is built around a 150 mm linear rail, though it could easily be lengthened or shortened to suit your needs. A T8 leadscrew, paired with anti-backlash nuts, translates the knob’s rotation into smooth linear motion. The knob itself uses a custom-designed anti-backlash mechanism to ensure the slider works cleanly in either direction.

You can grab all the 3D-printable files as well as the full bill of materials from the project page. Be sure to check out [Salveo]’s build video below. Thanks [Tim L.] for sending in this awesome open-source slider. Be sure to check out some of the other macro photography projects we’ve covered, too.

Continue reading “Tiny Moves, Big Depth: An Open-Source Macro Focus Slider” →

Dotterboard smt counter

Tame The Tape: Open-Source Dotterboard For Bulk SMT Parts

March 30, 2026 by 9 Comments

One of the great things about building electronics today is how affordable SMT components have become — sometimes just fractions of a cent each. That low price often means ordering far more than you need so you’ll have spares on hand the next time a project calls for them. Keeping track of exactly how many of each part you actually have, though, is rarely easy. To solve that problem, [John] built the Dotterboard, an open-source SMT tape counter.

While working on some of his other projects, [John] found himself managing thousands of tiny SMT parts and decided it was time to automate the counting. The Dotterboard takes inspiration from the BeanCounter — a compact, portable SMT tape counter — but expands the design to handle larger components beyond the 8 mm tapes the BeanCounter targets.

The Dotterboard is mostly 3D-printed and uses just a few common hardware parts such as springs and ball bearings. An OLED displays the current count, which comes from an encoder tracking movement and multiplying by the number of components per hole. At the heart sits an RP2040 Zero that needs nothing more than a single USB-C cable for power, unlike the bulky industrial SMT counters that demand AC outlets and desk space.

Be sure to check out all the details of the build on [John]’s website, and grab the files from his GitHub if you want to make your own. Let us know what are some projects you’ve done to save you the headache of doing the same task by hand for hours on end.

Continue reading “Tame The Tape: Open-Source Dotterboard For Bulk SMT Parts” →