Sometimes the best you can say about a project is, “Nice start.” That’s the case for this as-yet awful DIY 3D scanner, which can serve both as a launching point for further development and a lesson in what not to do.
Don’t get us wrong, we have plenty of respect for [bitluni] and for the fact that he posts his failures as well as his successes, like composite video and AM radio signals from an ESP32. He used an ESP8266 in this project, which actually uses two different sensors: an ultrasonic transducer, and a small time-of-flight laser chip. Each was mounted to a two-axis scanner built from hobby servos and 3D-printed parts. The pitch and yaw axes move the sensors through a hemisphere gathering data, but unfortunately, the Wemos D1 Mini lacks the RAM to render the complete point cloud from the raw points. That’s farmed out to a WebGL page. Initial results with the ultrasonic sensor were not great, and the TOF sensor left everything to be desired too. But [bitluni] stuck with it, and got a few results that at least make it look like he’s heading in the right direction.
We expect he’ll get this sorted out and come back with some better results, but in the meantime, we applaud his willingness to post this so that we can all benefit from his pain. He might want to check out the results from this polished and pricey LIDAR scanner for inspiration.
It’s really hard to overstate how awesome ESP8266 development boards like the Wemos D1 Mini really are. For literally a couple of dollars you can get a decently powerful Wi-Fi enabled microcontroller that has enough free digital pins to do some useful work. Like the Arduino and Raspberry Pi before it, the ESP8266 is a device that’s opening up whole new areas of hacking and development that simply weren’t as practical or cost-effective as previously.
As a perfect example, take a look at this stupendously simple Internet-connected motion detector that [Eric William] has come up with. With just a Wemos D1 Mini, a standard PIR sensor, and some open source code, you can create a practical self-contained motion sensor module that can be placed anywhere you want to keep an eye on. When the sensor picks up something moving, it will trigger an IFTTT event.
It only takes three wires to get the electronics connected, but [Eric] has still gone ahead and provided a wiring diagram so there’s no confusion for young players. Add a 3D printed enclosure from Thingiverse and the hardware component of this project is done.
Using the Arduino Sketch [Eric] has written, you can easily plug in your Wi-Fi information and IFTTT key and trigger. All that’s left to do is put this IoT motion sensor to work by mounting it in the area to be monitored. Once the PIR sensor sees something moving, the ESP8266 will trigger IFTTT; what happens after that is up to you and your imagination. In the video after the break, you can see an example usage that pops up a notification on your mobile device to let you know something is afoot.
If you’ve been in a Japanese restaurant, you’ve probably seen a maneki-neko, the lucky cat charm, where a cat welcomes you with a beckoning arm. It’s considered to bring good luck, but we’re not sure if [Martin Fitzpatrick] is pushing his luck with this Lucky Cat POV display. He hacked one of the figurines so the arm forms a persistence of vision (POV) display, where blinking LEDs on the paw create a dot-matrix style display.
Inside the hapless neko is a Wemos D1, motor driver, and a few other components that turn the cat into a working display. The five LEDs he attached to the paw are wide enough to display 5×7 characters. The tricky part in the mechanical design is getting signals from a stationary base to a spinning arm(ature). In this case it was easily solved with a 6-wire slip ring from Adafruit. [Martin] revs the lucky cat up using a brushed DC motor and a couple of gears.
The ESP8266 is running MicroPython — the combination should make this a snap to hook into any web service API you want to display your own messages. Right now the arm doesn’t have positional awareness so the message isn’t locked in a single position like it would be if a hall effect sensor was used. But [Martin] says there’s plenty of room left inside the cat and a future upgrade could include stashing the batteries inside for a cordless, all-in-one build. If he takes that on it’s a perfect time to add some type of shaft encoding as well.
Check the Lucky Cat showing off in the clip after the break.
How many of your projects been spawned purely out of bored daydreaming? For want of something more productive to do, [dantheflipman] hacked a standard LED bulb from Wal-Mart into a smart bulb.
After pulling it apart, they soldered wires to the threaded socket and added a connector for a Hi-Link hlk-pm01 power module. The output caps at 5 V and 600 mA, but who says this was going to be a searchlight? A Wemos D1 Mini clone slides nicely beside the power module, and stacked on top is a NeoPixel Jewel 7. [dantheflipman] admits he has yet to add a capacitor to ahead of the Jewel, so we’ll see how long the LEDs last. Crammed back together, the bulb is controlled via a prototype Blynk app. Good enough for a quick hack.
[dantheflipman] is upfront about messing with mains voltages: don’t do it unless you absolutely know what you’re doing. In this case, he has taken care with their soldering and epoxied all wire and solder joints to be sure nothing will come loose and short, and a ‘stress test’ is forthcoming.
Calling it the ESPecter, [ACROBOTIC Industries] wanted to make this a simple project for anyone, regardless of skill with a soldering iron or Arduino toolkit. So they decided to base the guts on common components that can be put together easily, specifically a Wemos Mini D1 with an OLED shield as a bright display. They also designed a cool tiltable 3D-printed enclosure for this small device so that you can orient it to your eye level.
If you study the specifications of the ESP8266 WiFi-enabled microcontroller, you will notice that it features an I2S audio interface. This is a high-speed serial port designed to deliver 16-bit audio data in a standard format, and has its origins in consumer audio products such as CD players. It would be usual to attach a dedicated DAC to an I2S interface to produce audio, but [Jan Ostman]’s synthesiser projects eschew that approach, and instead do the job in software. His I2S interface pushes out a pulse density modulated data stream in the same manner as a 1-bit DAC, meaning that the only external components required to produce audio are a simple low-pass filter. He’s posted a video of the synth in action, which we’ve placed below the break.
The example he gives us is a basic clone of a Roland 909 drum machine, and he takes us through the code with extensive examples including MIDI. He’s using the Wemos D1 Mini board, but the same could be replicated with many other ESP8266 platforms.
The secret to domestic bliss often lies in attention to detail, an area in which we can all do a little better. But if paper notes and smartphone reminders are not enough to help you remember to knock jobs off your list, perhaps this IoT task reminder will give you the edge you need to keep the peace at home.
As [Andreas Spiess] points out, his best intentions of scheduling recurring tasks in Google Calendar were not enough to keep him on on top of his share of chores around the house. He found that the notifications popping up on his phone were far too easy to swipe away in favor of other distractions, so he set about building a real-world reminder. His solution uses a WeMOS D1 Mini in a bright blue 3D-printed box with from one to four LED switches on the front. Each box is linked to his Google Calendar, and when a task comes due, its light turns on. Sprinkled about the house near the task, like the laundry room or near the recycling, [Andreas] can’t help but see the reminder, which only goes out when he cancels it by pressing the task button. Simple but effective, and full of potential for other uses too.
Of course, the same thing could be accomplished with a Magic Mirror build, which we’ve seen a lot of over the years. But there’s something about the simplicity of these devices and their proximity to the task that makes sense — sort of like the Amazon Dash concept. We might build a few of these too.