Building a clock of some sorts seems to be a time honored tradition for hackers and LED clocks seem one of the most popular. You can build anything from a seven-segment display to a binary clock or something even more fancy. [Clueless] found a circle of LED rings online and with made an LED version of an analog clock.
Controlling blinds using off the shelf solutions can be expensive – more so if you have multiple blinds you want to control. [HumanSkunk87] felt the cost was too high, so they designed a controller to automatically open and close the blinds.
The main part of this build is a motor and a ball chain gear – a wheel that captures the balls of a ball chain so that the chain can be pulled. The wheel was designed using Fusion3D and then printed out. The motor requires enough power to pull the chain — [HumanSkunk87] figures it needs to be able to pull about 2.5kg in order to raise the blind. After giving up on stepper motors, a DC motor with a worm gear was found to have enough torque to work. A WEMOS D1 Mini controls the motor controller that drives the ball chain wheel. Two micro switches tell the WEMOS when to stop at the bottom and top of the window.
The WEMOS is programmed using ESPHome and it connects to [HumanSkunk87]’s HomeAssistant to complete the automation. Check out the descriptions in the link for the parts and the code used to run everything. There are many other creative ways to open your blinds, It’s even possible to automate curtains instead of blinds.
It’s holiday time again! And that means it’s time to break out the soldering iron and the RGB LEDs! If you’re going to make a custom PCB to put those LEDs on, you’ll notice that you get few copies of your PCB in your order, so, might as well design it such that you can combine them all together into a single Sierpinski Christmas Tree, just like [Landon Carter] did.
Each PCB “tree” has three connections which can be used as either inputs or outputs by soldering one of two bridge connections on the PCB. The power and signal goes up and down through the tree, rather than across, so the connections go one on the top of the tree and two on the bottom. This way, each tree in the triangle can easily be connected, and each triangle can be easily connected to another. Each individual tree has three WS2812b-mini addressable RGB LEDs and the tree is controlled by an external Arduino.
The first order of 10 PCBs came in, which makes a 9 member tree – next up is a 27 member tree. After that, you’re going to need some pretty high vaulted ceilings in order to put these on the wall. On the upside, though, once the holidays are over, everything can be easily disconnected and packed away with the rest of the decorations. If you, too, are interested in RGB LED decorations, there are a few on the site for your perusal.
Are you still writing notes on paper and sticking them to the fridge like it’s the ’80s? Well, if you are, and you read this site, you’d probably like to upgrade to something a bit more 21st century. And, thanks to robot maker [James Bruton], you can leave your old, last century, message taking behind as he has a tutorial up showing you how to build an internet connected e-paper message display board. And, if you have a Raspberry Pi, an e-paper display and adapters just lying around doing nothing, then this project will cost you less than the buck that paper and a magnet will cost you.
Sarcasm aside, this is a pretty nice project. As mentioned, the base of this is a Raspberry Pi – [James] uses a Pi 4, but you could get away with an older, lower powered model as well. This powers the cheap(-ish) e-paper display he found online, which comes with the necessary adapters for the Pi, as well as a python library to write to the display. [James] uses a Google Sheet as the cloud storage for the message board, and there is some python code to access the cells in the Sheet and print them on the display if anything has changed. A cron job runs the script every 5 minutes to catch changes in the messages.
As with most of the projects that [James] does, he gives a good overview in the video and goes over the process of finding the hardware and writing and updating the script. He’s put the script and details as well as the CAD file for the frame he created for the project up on GitHub. [James] has been featured several times on the site before, check out some of his projects.
Security has always been an issue with IoT devices. Off the shelf devices often have terrible security while DIY solutions can be complicated, needing recompilation every time a website’s fingerprint changes. [Johannes] wrote in to let us know he’s been working on a way to make HTTPS requests easier to do on ESP devices.
The normal ways to do HTTPS with an ESP8266 is to either use Fingerprints, or to use client.setInsecure(). Fingerprints require the user to know exactly which pages the ESP will connect to and extract the Fingerprints from each of those websites. Since the fingerprints change yearly, this means the fingerprint will have to be re-extracted and the code recompiled each time a fingerprint changes. The use of client.setInsecure() is, obviously, insecure. This may not be an issue for your project, but it might be for others.
[Johannes’] solution is to extract the trusted root certificates and store them in PROGMEM. This allows access to any web page, but the root certificates do expire as well. As opposed to the fingerprints, though, they expire after 20 years, rather than every year, so the program can run for a long time before needing recompilation. This solution also doesn’t require any manual steps – the build process runs a script that grabs the certificates and stores them in files so that they can be
uploaded to the SPIFFS written to PROGMEM to be used during HTTPS requests.
He’s come up with a fairly straightforward way to have your IoT device connect to whichever web page you want, without having to recompile every once in a while. Hopefully, this will lead to better security for your IoT devices. Take a look at some previous work in this area.
When it comes to understanding computers, sometimes it’s best to get a good understanding of the basics. How is data stored? How does the machine process this information? In order to answer these questions a bit more and start learning programming, [Nakazoto] built a 10-bit binary adder with relays.
The build is designed from the ground up, including the PCBs, which are milled using a CNC machine. There are six boards: the input board, sequencer board, 2 sum register boards, a carry register board and a 1-bit ALU board. The input board has 32 LEDs on it along with the switches to turn on each bit on or off. In total, 96 relays are used and you can hear them clacking on and off in the videos on the page. Finally, there is a separate switch that sets the adder into subtraction mode.
Usually, [Nakazoto]’s website is mostly about cars, but this is a nice diversion. The article has a lot of detail about both the design and build as well as the theory behind the adder. Other articles on binary adders on the site include this one which uses bigger relays, and this 2-bit adder which uses 555 timers.
In the quest to automate everything in your home, you no doubt have things that aren’t made with home automation in mind. Perhaps your window AC unit, or the dimmer in your dining room. [Seb] has several ceiling fans that are controlled by remotes and wanted to connect them to his home automation system. In doing so, [Seb] gives a good overview of how to tackle this problem and how to design a PCB so he doesn’t have a breadboard lying around connected to the guts of his remote control.
There are several things [Seb] needs to figure out in order to connect his fans to Home Assistant, the home automation system he uses: He needs to determine if the circuit in the remote can be powered by 5 or 3.3 V, he needs to connect the circuit to an ESP32 board, and he needs to figure out if he can create a custom PCB that combines the circuit and the ESP32 into one. The video goes through each of these steps and shows the development of each along the way.
There’s a lot of info in the video, so it might need to be slowed down a bit to see all the details. There are some other reverse engineering of home automation gear on the site, here, or, you might want to build your own remote to control your automated devices.