A white stairwell ceiling with a rack holding clothes. The rack follows the slope of the ceiling and is attached to a series of ropes and pulleys to let it got up and down.

Stairway Drying Rack Rises Above The Rest

January 16, 2023 by Navarre Bartz 14 Comments

Finding space to dry clothes can be challenging in smaller spaces. [Tom Parker] solved this conundrum in his one bedroom apartment by putting a drying rack in his stairwell.

By making the laundry rack fold up above the stairwell, [Parker] can dry his clothes without them taking up a lot of precious floor space. A pole is used to is raise and lower a dowel rod attached to two lines of paracord running over pulleys and to the end of the rack. Each moving corner of the rack also has a set length of cord attached to prevent the rack from rotating too far down as well as providing a safety mechanism should one of the other lines of cord snap.

The rack is bolted-together, laser cut 1.5mm thick mild steel with 15 mm dowels attached to the sides via threaded inserts. Spacing is set for the raised rack to put clothes at 75 mm apart. Plywood pieces interface the rack with the wall to avoid damaging the drywall.

If you’re looking for more laundry hacks, check out this Smart Clothes Dryer or How Robots Suck at Folding Laundry.

A composite picture with a 3D printed cylinder with a magnet at one end held in a 3D printed housing ring on the left composite picture and a fridge buzzer board with buzzer, CR2032 battery, MCP430 microcontroller and hall effect sensor slid into a 3D printed base on the right part of the composite picture

Don’t Lose Your Cool With This Fridge Buzzer

January 16, 2023 by Abe Connelly 28 Comments

[CarrotIndustries] wanted to add an audible warning for when the refrigerator door was left open. The result is a fridge buzzer that attaches to the inside of a fridge door and starts buzzing if the door is left ajar for too long.

The main components of the fridge buzzer consist of an MSP430G2232 low-power MCU connected to a SI7201 hall sensor switch, along with a CR2032 battery holder, push button and buzzer. The MSP430’s sleep mode is used here, consuming less than 3 µA of current which [CarrotIndustries] estimates lasting 9 years on a 235 mAh CR2032 battery.

A 3D printed housing is created so that the board slides into a flat bed, which can then be glued onto to the fridge door. The other mechanical component consists of a cylinder with a slot dug out for a magnet, where the cylinder sits in a mounting ring that’s affixed to the side of the fridge wall that the end of the door closes on. The cylinder can be finely positioned so that when the refrigerator is closed, the magnet sits right over the hall sensor of the board, allowing for sensitivity that can detect even a partial close of the fridge door.

All source code is available on [CarrotIndustries] GitHub page, including the Horizon EDA schematics and board files, the Solvespace mechanical files, and source code for the MSP430. We’ve featured an IoT fridge alarm in the past but [CarrotIndustries]’ addition is a nice, self contained, alternative.

Ring In The New Year With This Cute Cat Doorbell

January 16, 2023 by Abe Connelly 5 Comments

What better way to ring in the new year than with [iSax Laboratories]’ charming little project that replaces a doorbell with a Maneki-Neko cat figurine to ring a physical bell?

Details are unfortunately a bit light, but it looks like the Maneki-Neko cat was disassembled to allow for a small SG92R servo motor to attach to the arm pendulum mechanism. [iSax Laboratories] added wooden platform where the Maneki-Neko cat figurine is mounted along with some indicator lights, switches and the physical bell, with a cavity routed out in the base to allow for the Arduino Nano microcontroller.

[iSax Laboratories] has what looks to be an Assa Abloy Svara 23 wired answering machine, which has one of its output lines connected to the Nano to sense when a doorbell signal has come in.

The Maneki-Neko cats are cute, easily hackable figurines and we’ve featured them in the past, using them as everything from hit counters to POV displays.

Be sure to check out the demo video after the break!

Continue reading “Ring In The New Year With This Cute Cat Doorbell” →

A thermostat unit and a replacement PCB for it

Custom Thermostat PCB Connects Boiler To Home Assistant

January 15, 2023 by Robin Kearey 24 Comments

Thanks to Home Assistant, automating the various systems that run your home is easier than ever. But you still need to make a connection between those systems and your Home Assistant setup, which can be tricky if the manufacturer didn’t have this use case in mind. When [Simon] wanted to automate his home heating system, he discovered that most Home Assistant-enabled thermostats that he could find didn’t support his two separate heating zones connected to a single boiler. The easiest solution turned out to be to design his own.

The original heating system consisted of two control boxes that each had a 230 V mains connection coming in and a “request heat” control line going to the boiler. [Simon] considered replacing these with a simple off-the-shelf ESP8266 relay board and a 12 V power supply, but figured this would look messy and take up quite a bit of space. So he bought a neat DIN-rail mounted enclosure instead, and designed a custom PCB to fit inside it.

The PCB holds a Wemos D1 Mini connected to two relays that switch the two heating circuits. The D1 runs ESPhome and needs just a few lines of configuration to connect it to [Simon]’s home network. There’s no separate power supply — the 230 V line is connected directly to a 12 V DC power module mounted on the PCB, so the new system is plug-and-play compatible with the old.

Complete PCB design files are available on [Simon]’s website and GitHub page. There are several other ways to make custom thermostats for your home, with an Arduino for example. If you’re interested in repairing your own heating system, or want to optimize it even further, there’s a whole community out there to help you.

An E-Ink Progress Bar For Your Unborn Child

January 13, 2023 by Tom Nardi 12 Comments

Having a child is a major milestone in a person’s life, and there’s a long list of things to get done before that little bundle of joy kicks and screams its way into the world. What better way to make sure you’ve still got time to paint the nursery and assemble the crib than to have an automated loading screen that shows just how far along the organic 3D printing process is?

This fetal development tracker was put together by [mokas] using Adafruit’s ESP32-S2 powered MagTag. As the name implies, the all-in-one electronic ink development board is designed so that it can be adhered to a metallic surface with integrated magnets. The idea is that you can pop a battery in the low-power device, stick it on your refrigerator, and have a regularly updated display of…well, whatever you want. Continue reading “An E-Ink Progress Bar For Your Unborn Child” →

Arduino Library Brings Rtl_433 To The ESP32

January 13, 2023 by Tom Nardi 10 Comments

If you have an RTL-SDR compatible radio there’s an excellent chance you’ve heard of the rtl_433 project, which lets you receive and decode signals from an ever-expanding list of supported devices in the ISM radio bands. It’s an incredibly useful piece of software, but the fact that it requires an external software defined radio and a full-fledged computer to run dictated the sort of projects it could realistically be used for.

But thanks to the rtl_433_ESP Arduino library developed by [NorthernMan54], we’re now able to pack that functionality into a much smaller package. All you need is an ESP32 microcontroller and a CC1101 or SX127X transceiver module. If you’re looking for a turn-key hardware platform, the documentation notes the LILYGO LoRa32 V2 board includes the required hardware, plus adds a handy OLED display and microSD slot. It should be noted that the range of these radios don’t compare particularly well to a full-size RTL-SDR device, but that probably won’t come as much of a surprise. Continue reading “Arduino Library Brings Rtl_433 To The ESP32” →

Concrete Coffee Table Can Take A Beating

January 13, 2023 by Zoe Skyforest 30 Comments

A good coffee table should have a hard-wearing surface and some serious heft to it. This build from [designcoyxe] hits both those criteria with its concrete-based design.

To create the table surface, the first step was to create a form. Melamine was used for the job, thanks to its smooth surface. A rectangular form was readily fabbed up, sealed internally and waxed, and then the concrete was poured. For added strength, the form was only half-filled, and a mesh was added for reinforcement. The rest of the concrete was then poured in to complete the tabletop. The table legs themselves were crafted out of maple, formerly used as a butcher’s block. The light wood makes a great contrast to the dark grey concrete. Plus, the stout, thick, wooden legs are a great combination with the strength of the tabletop itself.

It’s hard to overstate how good concrete is as a coffee table material. It’s difficult to damage and difficult to stain. Plus, if you really need to drive a point home, you can be certain slamming down your mug will get everyone’s attention (just be wary of injury). We’ve seen some other great concrete furniture before, too.

Continue reading “Concrete Coffee Table Can Take A Beating” →