A Sonoff Switch Repurposed As A Thermostat

Underfloor heating is a wonderfully luxurious touch for a bedroom and en-suite bathroom, and [Andy] had it fitted so that he could experience the joy of walking on a toasty-warm floor in the morning. Unfortunately after about a year it stopped working and the culprit proved to be its thermostat. A replacement was eye-wateringly expensive, so he produced his own using an ESP8266-powered Sonoff wireless switch.

The thermostat has a thermistor as its temperature sensor, embedded in the floor itself. This could be brought to the ESP’s solitary ADC pin, but not without a few challenges along the way. The Sonoff doesn’t expose the pin, so some very fine soldering was the first requirement. A simple voltage divider allowed the pin to be fed, but through it he made the unfortunate discovery that the ESP’s analogue input has a surprisingly low voltage range. A new divider tying it to ground solved the problem, and he was good to go.

Rather than using an off-the-shelf firmware he created his own, and with a bit of board hacking he was able to hard wire the mains cabling and use one set of Sonoff terminals as a sensor connector. The whole fit neatly inside an electrical fitting box, so he’s back once more to toasty-warm feet.

This isn’t the first ESP thermostat we’ve featured, nor will it be the last. Here’s a particularly nice build from 2017.

Not Happy with Smart Bulbs? Make Your Own

The idea of the so-called “smart bulb” sounds good; who wouldn’t want to be able to verify the porch light is on if you’re out of town for the night, or check to see if you left the bathroom lights on in your rush out the door in the morning? But in practice, it can be a nightmare. Each brand wants to push their own protocol. Even worse, it seems you can’t get anything done without signing up for three different services, each with its own application that needs to be installed on your phone. It’s a frustrating and often expensive mire to find yourself in.

[Dom Gregori] liked the Hue bulbs offered by Philips, but didn’t want to buy into the whole ecosystem of phone apps and hardware hubs they require. So he decided to create his own open source version that would do everything he wanted, without any of the seemingly unavoidable baggage of the commercial offerings. The final result is a professional looking ESP8266 controlled RGB bulb that hooks into Home Assistant via MQTT.

Looking at his Bill of Materials, it’s actually pretty amazing to see how little it really takes to pull a project like this off. Outside of the Wemos D1 Mini board, [Dom] just needed a few concentric WS2812 rings, and a USB charger small enough to fit into the base of his 3D printed enclosure.

We especially like how he handled the socket-side of the bulb, as that’s the part that would have left us scratching our heads. Rather than trying to salvage the base from an existing bulb, or come up with his own printed piece to stick in the socket, he just used a cheap and readily available light socket adapter. The solution might be a little bulky, but we like how he’s deftly avoided having to handle any AC voltages in this project.

Over the last couple years, we’ve seen more and more smart bulb related content come our way. From the ever popular teardown of a new entry into the market to the sobering realization that your light bulbs might provide the key attackers need to access your network, it’s been fascinating to see the transformation of these once simple pieces of hardware into something far more complex.

A DIY Sprinkler Controller Using An ESP8266

There is something strangely amusing about the idea of a sprinkler system relying on a cloud. But it was this limitation in some commercial offerings that led [Zack Lalanne] to create his own controller when it was time to upgrade his aging irrigator.

It’s a straightforward enough device, he’s taken an ESP8266 on the ubiquitous NodeMCU board, and added a shift register for some output line expansion to drive a set of relays. The interest here lies with the software, in which he’s used the ESPHome firmware and added his own custom part for the shift register. This change alone should be useful for many other experimenters with the ‘8266 and ESPHome combination.

The ESP8266 end of the device ties in with his instance of the Home Assistant home automation hub software. On this he’s been able to tie in all his various sprinkler outputs he added, and apply whatever automation scripts he chooses. The result is a freshly watered lawn, with not a cloud in the sky (or backend).

The value of this project lies only partly in its use for sprinkler owners, for us it also lies in the clear write-up showing the way for others with similar home automation tasks. It’s not the only way to make an ESP sprinkler controller, you should also see this one from 2017.

Reupholstering A Couch, With No Prior Experience

Upholstery is a craft that dates back far longer than many we feature on Hackaday. It requires patience, attention to detail, and a series of specialised skills. If you fancy yourself to be like a young Jack White, you might have considered trying your hand at a piece or two. [darkpine] did just that, and the results are impressive.

The couch was sourced from an online bartering platform, and was in a sad and sorry state after years of use. According to the original owner, the couch was over 100 years old and had been passed down through several generations. Last reupholstered in the 1970s, it was in dire need of repair. Wooden trim was falling off, fabric was fading, and resident cats had been sure to leave their mark.

[darkpine] set about things the right way, stripping the couch back to its bare bones. Taking careful note of the original construction, diagrams were made to ensure the springs could be retied in the correct fashion. Fresh burlap was installed, followed by foam and a layer of cotton batting. Careful attention was then paid to the fabric covering, with hand stitching used along the arms to get an absolutely perfect pattern match along the seams. With the hard part done, the wood was then restored and waxed to a glorious shine.

The final results are astounding, especially when noting that this was [darkpine]’s first ever upholstery project. We don’t see a lot of this kind of thing around here, but it’s not completely unknown.

[via Reddit]

In This Aussie’s Back Yard, No Cat Is Safe From An Automated Soaking!

Some of us here at Hackaday are cat lovers, but we also understand that a plethora of unwanted cats using a suburban back garden can be bothersome, and a few years ago we featured a project from Aussie YouTuber [Craig Turner], in which he created a motion-detecting water spray for use as a relatively harmless cat repellent. Now he’s back with an updated version which is a little slicker and easier to make.

At its heart is the same PIR-turns-on-water operation, but this time there is a solenoid valve and purpose-built nozzle instead of a car central locking actuator and a lawn sprayer. Doing the electronic work is an off-the-shelf PIR module, so there is no  longer any need to hack a security PIR detector. Add in some pipe sections and PTFE tape with a bit of hot glue, and the result is a far more professional and streamlined device. The video gives a full run-down on construction, though we notice he neglected to emphasise the polarity of his protection diode so keep an eye out if you follow his example.

So if the thought of a continuous supply of free feline company courtesy of your neighbours is not for you then now you are equipped to send them packing. The latest video incarnation of the project is below the break, but if you are in search of the original then you can go back to our coverage at the time.

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Custom Storage Boxes, From Cardboard and 3D Printed Bits

It’s not that storage boxes and organizers are hard to find. No, the problem this project set out to solve was more nuanced than that. The real trouble [theguymasamato] had was that his storage options — wide shelves and deep drawers — weren’t well suited to storing a lot of small and light objects. The result was a lot of wasted space and poor organization. To make matters worse, his big drawers had oddball dimensions, meaning that store bought organizers weren’t a good fit either.

To solve these problems, [theguymasamato] decided to design his own stackable boxes to store small and light objects far more efficiently than before. The design also allows the boxes to be made in a variety of sizes without changing any of the 3D printed parts. Carefully measured and cut cardboard is critical, but that’s nothing a utility knife and ruler can’t solve. The only other requirements are a few simple plastic parts, and some glue. He can fit six of these inside a single one of his drawers with enough room to access and handle them, but without wasting space.

Cardboard is really versatile stuff. Not only has it been behind some amazingly complex devices such as this tiny working plotter, but we’ve seen it form major components in the remarkably ambitious cardboard CNC.

This Owner Took Control Of Their Proprietary Alarm System

When a tip comes in and the tipster feels they have to reassure us that despite appearances their subject is not facilitating crime, it certainly gets our attention. [Flam2006] has a Brinks home security system which can only be configured using a special device only available to installers, and though they managed to secure one through an eBay sale they went to the trouble of reverse engineering its protocol and writing a software emulator in Python. When an owner hacks their own security system to gain full control of something they own, that’s right up our street.

The communication is via an RS485 serial line, and follows a packetised structure with binary rather than ASCII data. There is an almost plug-and-play system for identifying devices connected to a controller, though it is restricted to those devices which the controller already knows about. There is a video of the official method of programming the controller, as well as one of the software in action. We’ve posted them below the break for your delectation.

The ability to perform these tasks on your own property is an important right that has at times been placed under threat by legislation such as the DMCA. We’ve touched upon it countless times, but probably the most high-profile example that we and the wider media have covered are those stories concerning the parts lockdown on John Deere tractors.

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