Front Door Keys Hidden In Plain Sight

October 18, 2022 by Bryan Cockfield 27 Comments

If there’s one thing about managing a bunch of keys, whether they’re for RSA, SSH, or a car, it’s that large amounts of them can be a hassle. In fact, anything that makes life even a little bit simpler is a concept we often see projects built on to of, and keys are no different. This project, for example, eliminates the need to consciously carry a house key around by hiding it in a piece of jewelry.

This project sprang from [Maxime]’s previous project, which allowed the front door to be unlocked with a smartphone or tablet. This isn’t much better than carrying a key, since the valuable piece of electronics must be toted along in place of one. Instead, this build eschews the smartphone for a ring which can be worn and used to unlock the door with the wave of a hand. The ring contains an RFID which is read by an antenna that’s monitored by a Wemos D1 Mini. When it sees the ring, a set of servos unlocks the door.

The entire device is mounted on the front of the door about where a peephole would normally be, with the mechanical actuators on the inside. It seems just as secure (if not more so) than carrying around a metal key, and we also appreciate the aesthetic of circuit boards shown off in this way, rather than hidden inside an enclosure. It’s an interesting build that reminds us of some other unique ways of unlocking a door.

Continue reading “Front Door Keys Hidden In Plain Sight” →

Animated LED Arrows Point The Way

September 24, 2022 by Jonathan Bennett 11 Comments

Visitors at the Garden D’Lights in Bellevue, Washington had a problem. While touring the holiday lights show, they kept straying off the path. The event organizers tried some simple LED arrows, but they were just more points of light among a sea filled with them. This is when [Eric Gunnerson] was asked to help out. He’s apparently had some experience with LED animations, even cooking up a simple descriptor language for writing animations driven by an ESP32. To make the intended path obvious, he turned to a PVC board with 50 embedded WS2812 pixels –RGB controllable LEDs. The control box was a USB power adapter and an ESP8266, very carefully waterproofed and connected to the string of pixels. The backer board is painted black, to complete the hardware. Stick around after the inevitable break, to get a look at the final

The description of the build process is detailed and contains some great tips, but without a clever LED animation, it’s still of questionable utility. The pattern chosen is great, with the LEDs being blue most of the time, and a flame-like gradient chasing through the arrow every couple seconds. It’s obviously different from the lights of the show, and seems to be a real winner. [Eric] has published his code, with the sheepish caveat that he had to reinvent the wheel once again, and couldn’t reuse any of his previous LED animation work on this one. It’s a simple hack, but a great build log, and an effective solution to a subtle problem. And if addressable LEDs are your thing, check out our other hacks!

Continue reading “Animated LED Arrows Point The Way” →

Wireless Water Detector Hooks Up To Home Assistant

September 22, 2022 by Lewin Day 19 Comments

Water damage can quickly make even the nicest buildings unliveable. [Andres Leon] suffered a small flood from an air conditioning unit, and wanted to avoid such issues in future. Thus, he built a wireless monitor to solve the problem.

The device is based on the ESP8266, allowing it to wirelessly communicate with Home Assistant. Thus, if it detects water via its rust-proof probes, it can notify Home Assistant via an MQTT message. From there, Home Assistant can advise the home owner remotely via phone and email. Plus, just for completeness, there’s a loud buzzer in the unit that goes off when water is detected, too. Thanks to a 2500 mAh lithium-polymer battery on board, the device can run for up to 5 months between recharges.

Integrating warning systems into one’s smart home system can be particularly useful when one is away for long periods. Things like water leaks tend to do damage over time when we’re not paying attention, so any IoT device that can assist in this regard is helpful. If you want to investigate the cause of a difficult leak, though, this other project may help. Video after the break.

Continue reading “Wireless Water Detector Hooks Up To Home Assistant” →

Digital Light Pipes Clock various view of seven-segment display using illuminated light-pipes

LED Clock Has Its Pipes On Display

September 19, 2022 by Dave Walker 4 Comments

For most hackers and makers, building a clock is a rite of passage. Few, though, will be as unusual and engaging as this design by [TerraG2].

By combining addressable LEDs, light pipes and 7-segment displays, [TerraG2] has built a timepiece that looks great and will surely be a great conversation starter as well. It’s packed full of features such as automatic brightness control, an accelerometer controlled user interface, and WiFi to make sure it’s always accurate.

partial rear view of the clock showing illuminated light pipes — Partial rear view of the clock showing illuminated light pipes

The decision to leave the light pipes visible behind the main display really makes the project stand out from other clock builds, and the methods [TerraG2] has used to achieve this look will no doubt be transferable to a host of other projects.

The LEDs are courtesy of a standard 8×8 RGB matrix, with a custom 3D-printed shroud to hold the light pipes in place and a clever connector at the other end to illuminate the segments. With two LEDs per segment, seven segments per digit, and four digits, there’s even room for some extra features down the line if you can think of a use for those eight spare LEDs.

The brain of the project is an ESP8266 D1 with an MPU6050 inertial measurement unit (IMU) to detect when it’s flipped over to change the color scheme.

Full documentation is on Github, and a video of the clock in use is after the break.

Light pipes have been used to great effect in some other clock projects we’ve seen, such as this modern Nixie clock and this “clock of clocks”, as well as in this light organ that we showed recently.

Continue reading “LED Clock Has Its Pipes On Display” →

A Pill Dispenser For The Person With Everything

September 16, 2022 by Jenny List 15 Comments

Sorting out pills is a mildly tedious task, and one that’s ripe for a bit of automation. It’s a task that [Mellow] has taken on enthusiastically, with the result of an extremely well-designed dispenser that has a stack of hoppers with servos controlled by an ESP8266 that dispense the pills required on time.

There are a series of videos of which we’ve put the latest below the break, showing the various iterations of this project. Earlier versions used multiple microcontrollers rather than the single ESP, and his sensor choice is both simple and ingenious. A single vibration sensor detects the pills falling upon it, resulting on an extremely compact electronics set-up and the base of the 3D printed stack.

We’re struck by this design, by its simplicity, ingenuity, and its pleasing aesthetics with the use of a piece of perfboard and a load of heatshrink to make an extremely tidy wiring loom. We’re not sure we’ll ever need a pill dispenser like it, but if we did we don’t think we could come up with a better design.

You might be surprised to find that pill dispensers have appeared here before.

Continue reading “A Pill Dispenser For The Person With Everything” →

Water Monitor Measures The Cost Of Your Shower Thinking Time

August 26, 2022 by Danie Conradie 18 Comments

The shower is one of the top thinking places for many of us, but can get a bit out of hand with water wastage and utility bills if you go down a deep rabbit hole. To be more mindful of his water usage in the shower, [GreatScott!] created a power sipping water monitor that lives there.

The device is built around a cheap 1/2″ brass water flow rate sensor connected to his shower hose, which outputs pulses as a small wheel passes an internal hall effect sensor. The datasheet didn’t contain any spec for pulses/volume, so [GreatScott!] had to experimentally determine this by filling a one-liter container with water and counting the pulses. He found that the pulse count per liter was dependent on the flow rate, so he narrowed down the variables and just determined the average count at his shower’s pressure and flow rate.

The sensor is connected to a battery-powered ESP8266 housed inside a sealed 3D-printed enclosure in the shower. To reduce power usage to a minimum, a flow switch was added in series with the flow meter, which only switches on the ESP8266 when water starts flowing. A latching circuit keeps the ESP powered after the water stops, giving it enough time to transmit the data before shutting down. This type of circuit is very handy for any battery-powered project connected to an external switch or sensor.

It is programmed with ESPHome and outputs the data to a local Home Assistant server, so no data is saved on someone else’s server.

Continue reading “Water Monitor Measures The Cost Of Your Shower Thinking Time” →

An opened plastic project box with electronics inside

Smoking Meat Finds Natural Home In The Cloud

August 9, 2022 by Chris Wilkinson 15 Comments

Did you know that backyard barbecues now come with WiFi? It should be no surprise, given the pervasiveness of cloud-enabled appliances throughout the home. However [Carl] wasn’t ready to part with his reliable but oh-so-analog BBQ smoker, so instead he created an affordable WiFi-based temperature monitor that rivals its commercial counterparts.

Accurate temperature measurement is essential to smoking meat from both a taste and safety standpoint. In this project, two Maverick ET-732/733 thermistor probes take care of the actual temperature monitoring. One probe is skewered into meat itself, and the other measures the ambient ‘pit’ temperature. Combined, these two gauges ensure that the meat is smoked for exactly the right length of time. [Carl] mentions that adding an extra temperature sensor is trivial for larger setups, but he’s getting by just fine with two data points.

Naturally an ESP8266 does most of the heavy lifting in bridging the gap between smoke and cloud. At the core of this project is utility and practicality – temperature statistics can be viewed on any device with a web browser. Being able to study the temperature trends in this way also makes it easier to predict cooking times. Electronic alerts are also used to notify the chef if the temperature is too hot or cold (among other things). The entire contraption is housed in a smart looking project box that contains an LCD and rotary encoder for configuration.

If this has piqued your culinary interest, check out the extensive documentation recipe over on GitHub and the project Wiki. We also recommend checking out this project that takes automated meat smoking to the next level.