wemos d1 mini

45 Articles

Get The Party Started With A Mesh WiFi Light Show

June 26, 2020 by 1 Comment

Wildly blinking LEDs may not be the ideal lighting for the average office environment, but they’ll surely spice up any party. And since a party without music is just a meeting, having both synced up is a great way to set the mood. Sure, you could simply roll out your standard LED strip instead, but that gets a bit boring, and also a bit tricky if you want to light up several places the same way. [Gerrit] might have built the perfect solution though, with his (mu)sic (R)eactive (Li)ghts, or muRLi, which are a set of individual lights that synchronize a programmable pattern over WiFi.

The system consists of muRLi itself as the base station that defines and sends the light pattern through WebSockets, and several muRLi Nodes that house a set of WS2812B LEDs to receive and display it. Both are built around a Wemos D1 Mini configured to set up a WiFi mesh network, and depending what’s in reach, the nodes connect either to the base station or other nodes, giving the system definitely enough reach for any location size. The music is picked up by a MAX4466-amplified microphone inside the base station — adding some more flexibility to positioning the system — and analyzed for volume and audio spectrum, which is also shown on an OLED.

The best part however is how the light patterns are programmed. Instead of hard-coding it into the firmware, [Gerrit] went for a modular approach with little ROM cartridges to plug into the muRLi base station. The cartridge itself contains just an I2C EEPROM, storing JavaScript code that is interpreted by the firmware using mJS. The scripts have access to the analyzed audio data and amount of LEDs within the network, and can dynamically generate the patterns as needed that way. Everything is neatly housed in 3D-printed enclosures, with all the design and source files available on the project’s GitHub page — but see for yourself in the video after the break.

If you don’t care about the wireless part but enjoy light synced up with music, have a look at a plain MIDI solution for that. As for [Gerrit], we’re definitely looking forward to seeing his next endeavor one day, since we also enjoyed his last one.

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Quarantine Clock Answers The Important Question

May 5, 2020 by 20 Comments

For many people, these last few weeks have been quite an adjustment. When the normal routine of work or school is suddenly removed, it’s not unusual for your internal clock to get knocked out of alignment. It might have started with struggling to figure out if it was time for lunch or dinner, but now it’s gotten to the point that even the days are starting to blur together. If it takes more than a few seconds for you to remember whether or not it’s a weekday, [whosdadog] has come up with something that might help you get back on track.

Rather than showing the time of day, this 3D printed clock tells you where you are in the current week. Each day at midnight, the hand will advance to the center of the next day. If you wanted, a slight reworking of the gearing and servo arrangement on the rear of the device could allow it to sweep smoothly through each day. That would give you an idea of your progress through each 24 hour period, but then again, if you don’t even know if it’s morning or night you might be too far gone for this build anyway.

The clock’s servo is driven by a Wemos D1 Mini ESP8266 development board, which naturally means it has access to WiFi and can set itself to the current time (or at least, day) with NTP. All you’ve got to do is put your network information into the Sketch before flashing it to the ESP, and you’re good to go.

Naturally this project is a bit tongue-in-cheek, but we do think the design has practical applications. With a new face and some tweaked code, it could be an easy way to show all sorts of data that doesn’t require a high degree of granularity. Our very own [Elliot Williams] recently built a display to help his young son understand his new at-home schedule which operates on a similar principle.

Motorized LEGO Train Gets Qi Charging In The Track

March 22, 2020 by 6 Comments

This project started, as many do, with a simple idea. [Ben Hoad] just wanted to take a static LEGO Hogwarts Express train kit and make it motorized. It was compatible with standard LEGO track pieces, so all he should have to do was figure out how to shoehorn a motor in there and be done with it. Right?

Well, you already know how things like this go. It started with adding the motor, which ended up being relatively straightforward once [Ben] used some community LEGO CAD tools to figure out which kits had the specific parts he needed to redesign the train in such a way that he’d have enough space inside for the motor without ruining the way it looked. But then the feature creep kicked in, and he found himself falling down that familiar rabbit hole.

A 3D representation of the train’s internal components.

The first problem was how to reliably power the train. It turns out the rear car was more or less empty already, so that became home for two 18650 batteries (the project details say “16850” but we believe that is merely a typo). [Ben] didn’t want to have to take the thing apart every time it ran down, so he wondered if it would be possible to add wireless charging.

A Qi coil in the bottom of the train car and one in a specially designed section of track got the power flowing, but getting them lined up proved a bit finicky. So he added a Hall effect sensor to the car and a strong magnet to the track, so the train would know when the coils were lined up and automatically pump the brakes.

So now he had a motorized train that could recharge itself, but how should he turn it on and off? Well, with an ESP8266 along for the ride, he figured it would be easy to add WiFi control. With a bit of code and the Homebridge project, he was able to get the train to appear as a smart switch to Apple’s HomeKit. That allows him to start and stop the train from his smartphone, complete with a routine that returns the train to the charging station once it’s finished making the rounds. [Ben] says the next steps are to put some sanity checks in, such as shutting the motors down if the train hasn’t passed the charging station in a few minutes; a sure sign that it’s not actually moving.

All [Ben] needs to do now is implement automatic LEGO train decoupling before the plastic Hogwarts students come back from spring break.

Lovebox Gives Infinite Treats Sweeter Than Chocolate

January 22, 2020 by 8 Comments

Want to make a special Valentine’s Day gift that keeps on giving well past the holiday? We do too, especially if it’s something as cute as [Marcel Stör]’s Lovebox. This is a relatively simple build, but it’s the kind that lets you make someone’s day over and over again.

The sender composes their love note in a secret GitHub gist, either as a text message or a binary image, and updates the gist. Whenever the Wemos D1 mini inside the box receives a new message, a micro servo slowly wiggles the hearts up and down to notify the recipient.

Once they remove the lid to read it, a light-dependent resistor senses the flood of light on its face and tells the servo it can stop wiggling. We think it’s neat that the heart nudges upwardly at the box lid a bit as it moves, because it increases the cuteness factor.

Everybody loves to hear from that special someone throughout the day. The idea of sending an intimate message remotely is quite romantic, and there’s something thrilling and urgent about a physical notification. Show the break button a little love, and you’ll see a truffle-sized demo featuring both an incoming image and a text message.

[Marcel] was happy to ply his woodworking skills rather than use a laser cutter. If you have neither of these, hit up a craft store or two and you’ll find unfinished wooden boxes and pre-cut hearts galore. Or, you could just say it with copper.

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Weather Station Gets Much-Needed Upgrades

November 9, 2019 by 8 Comments

Weather stations are a popular project, partly because it’s helpful (and interesting) to know about the weather at your exact location rather than a forecast that might be vaguely in your zip code. They’re also popular because they’re a good way to get experience with microcontrollers, sensors, I/O, and communications protocols. Your own build may also be easily upgradeable as the years go by, and [Tysonpower] shows us some of the upgrades he’s made to the popular Sparkfun weather station from a few years ago.

The Sparkfun station is a good basis for a build though, it just needs some updates. The first was that the sensor package isn’t readily available though, but some hunting on Aliexpress netted a similar set of sensors from China. A Wemos D1 Mini was used as a replacement controller, and with it all buttoned up and programmed it turns out to be slightly cheaper (and more up-to-date) than the original Sparkfun station.

All of the parts and code for this new station are available on [Tysonpower]’s Github page, and if you want to take a look at a similar station that we’ve featured here before, there’s one from three years ago that’s also solar-powered.

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Creepy Halloween Doll Might Make You Betsy Wetsy

October 22, 2019 by 6 Comments

If you want to terrify your neighborhood this Halloween, you might go for the old standbys like skeletons or zombies. But you don’t have to go gory to find glory. Consider the talking doll. Those things are creepy enough already, right? Well, [cabuu] says no, the doll should be animated with servos and have remote control. She should still be able to talk, just not when you expect her to.

Forget pushing on her stomach, ’cause Baby’s got a Wemos D1 mini and her own Blynk app now.  A set of sliders in the app control a micro servo that animates her eyes, and another servo that twists her head from side to side. Her head doesn’t go all the way ’round, but that’s probably for the best. There are preset fright modes [cabuu] can set and forget until she springs to life via motion sensor.

We particularly like the bracket [cabuu] designed and printed that joins the eyeballs with the servo, along with his clever use of printed mate brackets to hold the servos in place within the head. If you think you can stomach it, there’s a demo video after the break. Stay tuned for total doll dissection after that as [cabuu] builds and inserts the terrifying tidbits.

We love hacks that combine innocence with insanity. Have you ever seen Thomas the Tank Engine singing Rick Astley?

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IKEA Cloud Lamp Displays The Weather With An ESP8266

June 12, 2019 by 5 Comments

The IKEA DRÖMSYN is a wall mounted cloud night light that’s perfect for a kid’s room. For $10 USD, it’s just begging for somebody to cram some electronics in there and make it do something cool. Luckily for us, [Jodgson] decided to take on the challenge and turned this once simple lamp into a clever weather display. It even still works as an LED lamp, if you’re into that sort of thing.

After stripping out the original hardware, [Jodgson] installed a Wemos D1 Mini and a string of fourteen SK6812 RGB LEDs that run down the length of the cloud’s internal structure. Weather data is pulled down with the OpenWeatherMap API, and conditions are displayed through various lighting colors and effects.

Sunny days are represented with a nice yellow glow, and a cloudy forecast looks like…well it’s already a white cloud so that one’s pretty easy. If rain is expected the cloud turns blue and the bottom LEDs flicker a bit to represent raindrops. When there’s a thunderstorm, the cloud will intermittently flash random LEDs on the strip a bit brighter than their peers; a really slick effect that gets the point across immediately.

This isn’t the first time we’ve seen somebody take a cheap light from IKEA and turn it into something much more impressive with the ESP8266. Just like with that previous project, we wouldn’t be surprised to see this particular modification popping up more in the future.