Put More Power In Your Dental Hygiene Routine!

July 2, 2023 by Jenny List 15 Comments

What do you do, when you move into a shared apartment and find only one socket is available among four electric toothbrushes? Revert to an old-style manual brush? If you’re [luisengineering], not a bit of it. He’s modified an electric toothbrush with the only sensible power plant, a three-horsepower twin cylinder four-stroke gasoline motor. You’ll need to turn on translated subtitles from the original German to watch it, but we hope you’ll agree it’s worth it.

After explaining the problem, the video below the break continues with the assembly of the motor, a model unit available through the usual online suppliers. This alone is interesting, for no doubt many of us have seen these motors for sale and retain some curiosity about them. We expected him to retain the electric drive for the toothbrush and use a generator, but instead, he hooks up the motor via a shaft directly to the input gear. With three horsepower behind the brush, this will surely shift that stubborn plaque! Astoundingly as you can see in the video below the break the contraption works, and both he and a friends perform their dental ablutions with it.

We like the blend of craziness and engineering embodied by this project, and we commend it to you on that basis. If you’re short of electric toothbrush modding ideas, how about an engraving tool?

Continue reading “Put More Power In Your Dental Hygiene Routine!” →

Ventbot fans with 3D printed brackets and control circuit board with ESP32 breakout and multicolored 3D printed cases

Ventbots Are Fans Of HVAC And Home Automation

June 24, 2023 by Michael Shaub 21 Comments

[WJCarpenter] had a common HVAC problem; not all the rooms got to a comfortable temperature when the heater was working to warm up their home. As often happens with HVAC systems, the rooms farthest from the heat source and/or with less insulation needed a boost of heat in the winter and cooling in the summer too. While [WJCarpenter] is a self-reported software person, not a hardware person, you will enjoy going along on the journey to build some very capable vent boosters that require a mix of each.

There’s a great build log on hackaday.io here, but for those who need more of a proper set of instructions, there’s a step-by-step guide that should allow even a beginner hardware hacker to complete the project over on Instructables. There you’ll find everything you need to build ESPHome controlled, 3D printed, PC fan powered vent boosters. While they can be integrated into Home Assistant, we were interested to learn that ESPHome allows these to run stand-alone too, each using its own temperature and pressure sensor.

The many iterations of hardware and software show, resulting in thoughtful touches like a startup sequence that checks for several compatible temperature sensors and a board layout that accommodates different capacitor lead spacings. Along the way, [WJCarpenter] also graphed the noise level of different fans running at multiple speeds and the pressure sensor readings against the temperatures to see if they could be used as more reliable triggers for the fans. (spoiler, they weren’t) There are a bunch of other tips to find along the way, so we highly recommend going through all that [WJCarpenter] has shared if you want to build your own or just want some tips on how to convert a one-off project to something that a wider audience can adapt to their own needs.

See a video after the break that doesn’t show the whole project but includes footage of the start-up sequence that tests each fan’s tachometer and the customizable ramp-up and ramp-down settings. Continue reading “Ventbots Are Fans Of HVAC And Home Automation” →

No Frills Autonomous Lawnmower Gets The Job Done

June 21, 2023 by Danie Conradie 19 Comments

[Nathan] needed an autonomous mower to help on the farm, so he built his own without breaking the bank. It might not be the prettiest machine, but it’s been keeping his roads, fences and yard clear for over a year. In the video after the break, he gives a detailed breakdown of its build and function.

It’s built around a around a simple angle-iron frame with a normal internal combustion push mower at it’s core. 18″ bicycle-type wheels are mounted at each corner, each side driven by an e-bike motors via long bicycle chains. Nathan had to add some guards around his wheel sprockets to prevent the chains slipping of due to debris.

Al the electronics and the battery is simply mounted on top of the frame, away from the motors to avoid magnetic interference with the compass. The brain of the system is a Pixhawk autopilot with a GPS module running ArduPilot, a staple for most of the autonomous rovers, boats and aircraft we’ve seen. The control station is just a Windows laptop running Mission Planner, with a 900 MHz radio link for comms with the mower. [Nathan] also gives a overview of how he uses a spreadsheet to set up waypoints.

This lawnmower’s straightforward design and use of easy-to-find components make it an excellent source of inspiration for anyone looking to build their own functional machine.

Continue reading “No Frills Autonomous Lawnmower Gets The Job Done” →

Google Home Scripting

June 14, 2023 by Al Williams 14 Comments

It is always controversial to have home assistants like the ones from Google or Amazon. There are privacy concerns, of course. Plus they maddeningly don’t always do what you intend for them to do. However, if you do have one, you’ve probably thought about something you wanted to do that would require programming. Sure, you can usually do a simple list, but really writing code wasn’t on the menu. But now, Google Home will allow you to write code. Well, at least script using a YAML file.

The script language is available in the web app and if you opt in on the mobile app as well. There’s a variety of ways you can trigger scripts and many examples you can start with.

Continue reading “Google Home Scripting” →

Moving The Snail Mail To WiFi

June 7, 2023 by Matthew Carlson 22 Comments

[Zak] loves getting a notification on his phone when he gets physical mail. Enough to wire his mailbox slot with an ESP8285 to send him alerts. Previously, [Zak] used a cellular-based solution as the mailbox slot was not within WiFi range. However, the network provider for the A9G GPRS module decided to move to different towers, and suddenly the module didn’t work. Unable to find a provider that had sensible pricing, he got to work redesigning the module.

The mailbox was now in a WiFi network range, meaning he no longer had to use cellular. This dramatically simplifies the design and uses an ESP-M2 module (think ESP8266 but with embedded flash). To maximize battery life, the ESP is entirely off most of the time. A reed switch triggers a 74LVC1G98 NAND gate with an inverted input. This enables the 3.3 voltage regulator. A 4uF capacitor holds the voltage regulator on for 716ms, giving the ESP8266 time to boot and drive the second pin of the logic gate so it can stay on. Once the web request completes (a call to a PHP server that takes 4-5 seconds, including WiFi association), it pulls the pin low, and the system powers off. With a custom server, [Zak] can include a few goodies, such as temperature and humidity from the SHT32-DIS sensor.

So far, the system has been chugging along for seven months and over 110 mail notifications and has only dropped 0.3v, suggesting that the battery should hold out for another year or two before recharging. The code and schematics are up on GitHub. We love the low-power focus and the handy circuit explanation that makes it easy to use in other projects.

Reverse Engineering A Better Night’s Sleep

June 6, 2023 by Dan Maloney 8 Comments

All you want is a decent night’s sleep, so you decide to invest in one of those fancy adjustable beds. At first, it’s fine — being able to adjust the mattress to your needs on the fly is a joy, and yet…something isn’t quite right. Something nags at you every night, thwarting your slumber and turning your dreams of peaceful sleep into a nightmare once you realize your bed has locked you into a vertically integrated software ecosystem from which there’s no escape.

Or is there? That’s what [Chris Laplante] wanted to know, and why he reverse-engineered his Tempur-Pedic remote control. As many products these days do, his bed was touted as having an Android application for smartphone adjustability, but alas, the app hasn’t been updated since 2014 (!) and doesn’t appear to work on modern phones. [Chris] decided to take matters into his own hands and build a gateway to talk to the bed using its native RF protocol.

Most good reverse engineering stories start with research, and this one is no exception. Digging into the FCC database revealed a wealth of clues, such as the frequency — 433-MHz ISM band, no surprise — and even spectrum analyzer screenshots of the remote’s signals. A HackRF One revealed more about the signals, but it turned out that sniffing in on the SPI bus between the microcontroller and the Si4431 RF transceiver with a Salae logic analyzer was more fruitful, allowing him to dig into the packet structure.

The engineers at Tempur-Pedic threw quite a few challenges at [Chris], like an application-level CRC in addition to the CRC used by the Si4431, and interesting complications to control the massage features of the bed. In the end, [Chris] managed to get a pretty complete snapshot of the conversation between the bed and the remote, and is now in the process of building a gateway that’ll actually connect to his phone, plus integrate into his home automation system. We’re looking forward to updates on that.

A Lightweight Smart Home Server

June 6, 2023 by Bryan Cockfield 31 Comments

Working towards automating a few things in a home often seems simple on the surface, but it’s easy for these projects to snowball into dozens of sensors and various servos, switches, and cameras strewn about one’s living space. The same sort of feature creep sneaks into some of the more popular self-hosted home server platforms as well, with things like openHAB requiring so much computing power that they barely function on something like a Raspberry Pi. [Paulo] thought there should be a more lightweight way of tackling a project like this, and set about building his own smart home server with help from some interesting software.

The project is based around the Dirigera hub from Ikea, partially because [Paulo] is planning to use other smart home devices from Ikea as he can easily find them where he is, and also because these devices tend to use Zigbee, a non-proprietary communications standard. This means that if he ever wants to swap out the hub for another one in the future, it won’t be difficult to do. From here the major hurdle is that using the default software from these devices is fairly limiting, so [Paulo] reached for a Raspbee 2 Zigbee gateway for use with a Raspberry Pi and an extremely lightweight and customizable web server called Mako to make this happen. Using Lua as the high-level language to tie everything together he was able to easily deploy the server to control the Ikea hub and devices and automate them in any way he sees fit.

While it is true that software like openHAB and others already exists to do virtually any home automation task that could be imagined, if you’re looking to do something with a bare minimum of computing power something like [Paulo]’s solution is likely going to be the fastest and most reliable method of getting a few things automated around the home. If you’re looking for something completely open source and built from the ground up, though, we have seen a few alternative smart home solutions like this one which don’t rely on any proprietary hardware or software, but do take a little bit more effort on the user’s part.