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 Lewin Day 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” →

An All-Billet, Single-Piece, Flexure-Based Nutcracker

January 11, 2023 by Lewin Day 22 Comments

Typical nutcrackers rely on simple pin hinges to join two handles for the cracking task. However, [adam the machinist] has demonstrated that a single-piece nutcracker is possible by using the flexural properties of the right grade of steel.

The nutcracker is manufactured out of 17-4 PH stainless steel, heat treated to the H900 condition. A flexural spring section at the top of the nutcracker takes the place of the usual hinge, allowing the handles to be squeezed together and the teeth of the cracker to open the nut. Machining the flexural section is first achieved with a series of CNC drill operations on the billet stock, before regular milling is used to shape the rest of the spring section and tool. The video dives deep into the finer points of the CNC operations that produce such a great finish on the final part. It even covers the use of a tiny scissor jack to help hold the handles still during machining.

The result is a highly attractive and desirable nutcracker that looks far more special than the regular fare you might pick up at Walgreens. The all-billet tool is a nutcracker very much fit for a sci-fi set. We’ve seen some other kitchen tools around here before, too, albeit of more questionable utility.

Continue reading “An All-Billet, Single-Piece, Flexure-Based Nutcracker” →

All Aboard The Garbage Express

January 2, 2023 by Bryan Cockfield 39 Comments

Cog railways are a somewhat unusual way of train locomotion, typically only installed when a train needs to climb steep terrain. Any grade above about 10% needs the extra traction since the friction between the wheels and rails won’t be enough to push the train forward or keep it from falling backwards. Even without a steep hill to climb, sometimes a cog railway is necessary for traction as [Max Maker] discovered while building a train for his garbage cans.

The build started out as a way to avoid having to wheel his seven waste bins to the curb every month. Originally he built a more standard railway with a simple motor to drive the train, but he quickly realized that there wasn’t enough grip even when using plastic wheels, even though this track follows fairly flat terrain. Since the rail is built out of steel he quickly welded up a rack-and-pinion system to one of the rails. The build goes through many iterations before he finally settles on a design that solves the problem, and it includes several other features as well such as remote control and a spring-loaded automatic charger for the train at its station in the back yard.

While we always appreciate the eccentricity of those who would automate a relatively simple task that only happens once a month, [Max Maker] hopes to build this into a commercial product aimed at the elderly or disabled who would really benefit from a reliable, semi-automatic system that takes their trash bins to the curb for them. And, if your system only involves a single trash can, there are other ways of automating the task of taking the garbage to the curb.

Continue reading “All Aboard The Garbage Express” →