Serving The Feline Masters: A Chair To Follow The Sunny Spot

January 17, 2021 by Danie Conradie 21 Comments

Terry Pratchett once wrote, “In ancient times cats were worshipped as gods; they have not forgotten this”. [Jonathan]’s cat has clearly not forgotten, and makes it loudly known whenever her favorite chair needs to be moved to stay in the spot of sunlight. He was looking for a fun hack anyway, so he decided to give in to her majesty’s demands, and automated the task.

[Jonathan] first considered adding motorizing the chair itself, but decided to keep it simple and just drag the chair across the room with a spool attached to a motor. The rope spool was attached to a small geared DC motor, mounted on a salad bowl base, and connected to an ESP8266 via a motor driver. The ‘8266 is running NodeMCU with a web server that accepts simple motor commands through a RESTful API. This setup can’t reset the chair to it’s starting position at the end of the day, but this is a small price to pay for simplicity. The motor was a bit underpowered, but it only needed to move the chair in small distances at a time, so [Jonathan] removed the chair’s back to reduce the weight, and upped the motor voltage.

Determining when and how far to move the chair is the second part of the challenge. [Jonathan] considered a simple lookup table for the time of day, but the motor’s movement wasn’t consistent enough. The final solution was a set of three BH1750 digital ambient light sensors to give feedback. A pair of sensors on the chair determines its position relative to the sunny spot, by comparing light levels to a reference sensor mounted in the window. These light sensors are also attached to NodeMCUs, and send movement commands to the winding unit as necessary.

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Is Your Echo Flex Listening?

January 14, 2021 by Al Williams 42 Comments

We are always surprised that Amazon or Google doesn’t employ Kelsey Grammer — TV’s Frasier — as a spokesman for their smart home devices. After all, his catchphrase was, “I’m listening…” Maybe they don’t want to remind you that the device could, theoretically, be sending everything you say to them or a nefarious hacker or government agency. Sure, there’s a mute button and it lights up a red LED.

But if you are truly paranoid, that’s not enough. After all, the same people want to eavesdrop on you would be happy to fake a red light. [Electronupdate] had the same thought and decided to answer the question: does the mute button really mute your microphone? The answer required not only some case opening and analysis, but there was even some IC decapsulation.

We were impressed with the depth of the analysis. The tiny SMD parts are marked confusingly, and if you are really paranoid you don’t believe them anyway. But looking at the actual circuit die is pretty unambiguous. The parts in question turned out to be a Schmitt trigger, a flip flop, and a NAND gate.

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Ask Hackaday: What’s In Your Fastener Bin?

January 11, 2021 by Dan Maloney 143 Comments

A Saturday afternoon. The work week was done, the household chores were wrapped up, and with almost a week left until Christmas, there was just enough wiggle room to deny that there was still a ton of work left to prepare for that event. It seemed like the perfect time to escape into the shop and knock out a quick project, one that has been on the back burner since at least March. I’m nothing if not skilled in the ways of procrastination.

This was to be a simple project — adding an aluminum plate to a plastic enclosure that would serve as an antenna entry point into my shack. Easy as pie — cut out an rectangle of aluminum, cut and drill a few holes, call it a day. Almost all of my projects start out that way, and almost every time I forget that pretty much every one of those builds goes off the rails at exactly the same point: when I realize that I don’t have the fasteners needed. That’s what happened with this build, which had been going swimmingly up to that point — no major screw-ups, no blood drawn. And so it was off to the hardware store I trundled, looking for the right fasteners to finish the job.

Finding hardware has long been where my productivity goes to die. Even though I live a stone’s throw from at least half a dozen stores, each with a vast selection of hardware and most open weekends and nights, the loss of momentum that results from changing from build-mode to procure-mode has historically been deadly to my projects. I’m sure I’m not the only one who has run into this issue, so the question is: what can a hacker do to prevent having to run out for just the right fasteners?

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Automating Your Car With A Spare Fob And An ESP8266

January 6, 2021 by Tom Nardi 47 Comments

Despite the name, home automation doesn’t have to be limited to only the devices within your home. Bringing your car into the mix can open up some very interesting possibilities, such as automatically getting it warmed up in the morning if the outside air temperature drops below a certain point. The only problem is, not everyone is willing to start hacking their ride’s wiring to do it.

Which is exactly why [Matt Frost] went the non-invasive route. By wiring up an ESP8266 to a cheap aftermarket key fob for his Chevrolet Suburban, he’s now able to wirelessly control the door locks and start the engine without having to make any modifications to the vehicle. He was lucky that the Chevy allowed him to program his own fob, but even if you have to spend the money on getting a new remote from the dealer, it’s sure to be cheaper than the repair bill should you cook something under the dash with an errant splice or a misplaced line of code.

The hardware for this project is about as simple as it gets. The fob is powered by the 3.3 V pin on the Wemos D1 Mini, and the traces for the buttons have been hooked up to the GPIO pins. By putting both boards into a custom 3D printed enclosure, [Matt] came up with a tidy little box that he could mount in his garage and run off of a standard USB power supply.

On the software side of things [Matt] has the device emulating a smart light so it can easily be controlled by his Alexa, with a few helpful routines sprinkled in that allow him to avoid the awkward phraseology that would be required otherwise. There’s also a minimal web server running on the microcontroller that lets him trigger various actions just by hitting the appropriate URLs, which made connecting it to Home Assistant a snap. One downside of this approach is that there’s no acknowledgement from the vehicle that the command was actually received, but you can always send a command multiple times to be sure.

This isn’t the first time we’ve seen an ESP8266 used to “push” buttons on a remote. If you’ve got a spare fob for your device, or can get one, it’s an excellent way to automate it on the cheap.

Never Forget To Turn On The Cooker Hood Again

January 4, 2021 by Jenny List 34 Comments

The cooker hood is a wonderful invention for removing excess fumes and steam from the kitchen. But like all electrically-powered devices, it only works when it is turned on. This was the problem facing [Peter], whose family are enthusiastic cooks who frequently forget to hit that switch. His solution? An automatic cooker hood switch that comes on when the cooker is in use, and stays on long enough afterwards to fully dissipate the fumes.

At its heart is a current transformer on the 3-phase stove power line, and we’re treated to a lesson in reading from these devices with an Arduino. They have a shunt resistor across which to produce a voltage, and their AC output is placed upon a reference DC voltage to supply the microcontroller pin. The impedance is quite high, so when the sensor had to be placed a distance from the microcontroller it necessitated an op-amp buffer. The readings then cause the Arduino to trigger a pair of relays to switch on or off the cooker hood. We can imagine that the family kitchen is thus a much pleasanter environment for it.

Cookers can also provide quite a hazard when they are left on. To that end, we’ve also featured a cooker alarm in the past.

Header image: Pbroks13, CC BY-SA 3.0.

More 3D Printed IKEA Hacks Make Life Better

December 29, 2020 by Al Williams 28 Comments

There’s an old joke that the CEO of IKEA is running to be Prime Minister of Sweden. He says he’ll be able to put together his cabinet in no time. We don’t speak Swedish, but [Adam Miklosi] tells us that the word “uppgradera” means “upgrade” in Swedish. His website, uppgradera.co has several IKEA upgrade designs you can 3D print.

There are currently six designs that all appear to be simple prints that have some real value. These are all meant to attach to some IKEA product and solve some consumer problem.

For example, the KL01 is a cup holder with a clip that snaps into the groove of a KLIPSK bed tray. Without it, apparently, your coffee mug will tend to slide around the surface of the tray. The CH01 adds a ring around a cheese grater. There are drains for a soap dish and a toothbrush holder, shoulder pads for coat hangers, and a lampshade.

We worry a little about the safety of the cheese grater and the toothbrush because you will presumably put the cheese and the toothbrush into your mouth. Food safe 3D printing is not trivial. However, the other ones look handy enough, and we know a lot of people feel that PLA is safe enough for things that don’t make a lot of contact with food.

Honestly, none of these are going to change your life, but they are great examples of how simple things you can 3D print can make products better. People new to 3D printing often seem to have unrealistic expectations about what they can print and are disappointed that they can’t easily print a complete robot or whatever. However, these examples show that even simple designs that are easily printed can be quite useful.

If you don’t have a printer, it looks like as though site will also sell you the pieces and they aren’t terribly expensive. We don’t know why IKEA invites so many hacks, but even they provide 3D printer files to improve the accessibility of some products.

Making Smart Bulbs Smarter With The Power Of MQTT

December 25, 2020 by Erin Pinheiro 14 Comments

What’s the point of smart home automation? To make every day tasks easier, of course! According to [Tomasz Cybulski], that wasn’t the case when he installed IKEA smart lights in his closet. It’s handy to have them in a common switch, in this case a remote control, but having to look for it every time he needed the lights could use some improvement. Enter his project to make smart bulbs smarter, through the use of a simple ESP8266.

While hooking a door switch to the lights’ power supply could provide a quick solution, [Tomasz]’s wife wanted to keep the functionality of the remote control, so he had to look elsewhere. These light bulbs use the simple Zigbee protocol, so arranging for other devices was rather trivial. A USB dongle to interface with the protocol was configured for his existing Raspberry Pi automation controller, while an ESP8266 served as the real-world sensor by connecting it to reed switches installed in the closet doors.

With all the hardware sorted out, it’s a simple matter of making it all talk to each other. The ESP8266, using the Tasmota firmware, sends a signal to an MQTT server running on the Raspberry Pi, which in turn translates it to a remote trigger on the Zigbee frequency with the dongle. The lights turn on when the door opens, and off again once it closes. And since there were no further modifications to the lights themselves, the original IKEA controller still works as expected, which we’re sure [Tomasz]’s wife appreciates!

MQTT can be an interesting piece of software that goes beyond just home automation though, and if you already have a server in your home you can use it to transfer your clipboard’s contents to another device. If you are using it for home automation though, here’s an inspiration for a rather unusual dashboard to keep things interesting. Check out this hack in action after the break.

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