Hackaday Prize 2023: LASK4 Watches Those Finger Wiggles

June 2, 2023 by Matthew Carlson No comments

What do you get when you combine an ESP32-S2, a machine-learning model, some Hall effect sensors, and a grip exercise toy? [Turfptax] did just that and created LASK4. The four springs push down pistons with tiny magnets on them. Hall effect sensors determine the piston’s position, and since the springs are linear, the ESP32 can also estimate the force being applied on a given finger. This data is then streamed to a nearby computer over TCP. A small OLED screen shows the status, and a tidy 3D printed case creates a comfortable package.

So other than an excellent musical instrument, what is this good for? First, it creates well-labeled training data when combined with what is collected by the muscle sensor band we discussed previously. The muscle band measures various pressure sensors radially around the forearm. With just a few minutes of training data, the system can accurately predict finger movement using the random forest regression model.

What would you use it for? It’s considered a somatosensory device, so it can be used for physical therapy when undergoing hand rehabilitation, as it provides feedback during sessions. Or it could be used to train a controller efficiently.

It’s an exciting project on GitHub under an OpenCERN hardware license. The code is in MicroPython, and the PCB and STL files are included. We’re looking forward to seeing what else comes from the project. After the break, there’s a progress update video.

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Pretty Small Robot Is Capable, Nonetheless

May 30, 2023 by Lewin Day 5 Comments

When science fiction authors imagined robots in the 20th century, many of them were huge imposing steel automatons. [Shane]’s designs for the Pretty Small Robot are quite contrary to that, being tiny in stature and cute in affect .

The whole robot is an exploration in nifty engineering. It uses an easy clip-together structure with fasteners and glue not required. The chassis is 3D printed, with all the components sliding into place. Two small DC gearmotors are used for differential drive, with each side of the robot having a pair of wheels wrapped in a rubber band for traction. The brains of the robot is an ESP32, providing it with both plenty of processing power and good connectivity options. Control is over WiFI via MQTT.

At this stage the robot doesn’t do a whole lot, though [Shane] has some exciting plans. He’d like to add a camera in future and let it explore a maze under human command.

If you’ve ever wanted to build a robot with an almost coin-sized foot print, this build is for you. Files are available on GitHub for those wishing to dive deeper. Video after the break.

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Ultimate Garage Door Control Does The Job Brilliantly

May 30, 2023 by Lewin Day 21 Comments

[Stephen Carey] had previously relied on an Insteon garage door controller, only to have it perform poorly and fail at integrating with Alexa properly. Thus, he did what any good hacker would do, and built his own system instead.

The garage door was first outfitted with a pair of reed switches to sense when it was fully open or fully closed. The drive sprocket of the garage door was also set up to be monitored with magnets and Hall effect sensors, essentially creating a rotary encoder. This allows a ESP32 to monitor the door’s direction of travel, it’s position, and when it has hit the end stop in either direction. Using Micropython, [Stephen] whipped up some code to tie the garage door controls in with Home Assistant, complete with a neat visual display of the current door position.

There are millions of home automation products out there, many of which make annoying compromises that frustrate the end user. Sometimes, doing it your own way is the only way to get satisfaction!

Hackaday Prize 2023: EyeBREAK Could Be A Breakthrough

May 30, 2023 by Matthew Carlson 4 Comments

For those with strokes or other debilitating conditions, control over one’s eyelid can be one of the last remaining motor functions. Inspired by [Jeremiah Denton] blinking in Morse code on a televised interview, [MBW] designed an ESP32-based device to decode blinks into words.

While an ESP32 offers Bluetooth for simulating a keyboard and has a relatively low power draw, getting a proper blink detection system to run at 20 frames per second in a constrained environment is challenging. Earlier attempts used facial landmarks to try and determine, based on ratios, whether an eye was open or closed. A cascade detector combined with an XGBoost classifier offered excellent performance but struggled when the eye wasn’t centered. Ultimately a 50×50, 4-layer CNN in TensorFlow Lite processes the camera frames, producing a single output, eye open or closed. For debugging purposes, it streams camera frames over Wi-Fi with annotations via OpenCV, though getting OpenCV to compile for ESP32 was also nontrivial.

[MBW] trained the model using the MRL dataset and then quantized to int8. Getting the Bluetooth and Wi-Fi stacks to run concurrently was a bit of a pain, as was managing RAM. After exhausting SRAM and IRAM, [MBW] had to move to PRAM. The entire system is built into some lightweight goggles and makes for a fairly comfortable experience.

While TensorFlow and microcontrollers might seem like a bit of an odd couple, at the end of the day, the inference engine is just doing some math on an array of inputs with some weights. We’ve even seen TensorFlow Lite on a Commodore 64. If you don’t know about [Admiral Jerimiah Denton] we can shed some light on it for you.

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DIY 3D Printed Rain Gauge Connects To Home Assistant

May 30, 2023 by Danie Conradie 16 Comments

Measuring local rainfall has real practical uses, especially in agriculture, but most of us will have to admit that it’s at least partly about drawing cool graphs on a screen. Whatever your motivation, you can build this open source electronic rain gauge designed by [Sebastian] of Smart Solutions for Home, and integrate it with Home Assistant.

This 3D printed rain gauge is of the ubiquitous tipping bucket type and uses a magnet and hall effect sensor to detect every time the bucket tips out. The sensor is soldered to a custom PCB with ESP32 configured using ESP Home. By keeping it in deep sleep most of the time and only waking up when the tip of the bucket, [Sebastian] estimates it can run about a year on four AA batteries, depending on rainfall. The hinge mechanism is adjustable to ensure that both buckets will tip with the same volume of water.

FDM 3D printed enclosures are not known for being waterproof, so [Sebastian] coated the PCB with varnish to protect it from moisture. This worked well enough that he could leave it running in a bowl of water for a few hours without any ill effects. The end result looks good and should be able to handle the outdoors for a long time.

Building a weather station is a popular DIY project. Some of the interesting varieties we’ve seen are powered by supercapacitors, show readings on antique analog dials and convert parking distance sensor kit into a wind gauge.

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Hacking The IKEA OBEGRÄNSAD LED Wall Lamp

May 25, 2023 by Donald Papp 18 Comments

The IKEA OBEGRÄNSAD is a pixel-style LED wall lamp that comes with a few baked-in animations, and [ph1p] improved it immensely with an ESP32 board and new firmware. The new controller provides all kinds of great new abilities, including new modes and animations, WiFi control, and the ability to send your own images or drawings to the panel. All it takes is desoldering the original controller and swapping in a programmed ESP32.

Hacking in a new controller provides a whole new range of capabilities.

Sadly, opening the unit up is a bit of a pain. It seems the back panel is attached with rivets rather than screws, but it will yield to a little bit of prying force.

The good news is that once the back panel is off, the inside of the OBEGRÄNSAD is very hackable. All the parts and connectors are easily accessible from where they are, and a nicely-labeled pin header makes a convenient attachment point for the new ESP32 board. There’s no need to disassemble any further once the back is off, and that’s always nice.

Going a bit smaller, we’ve also seen an IKEA LED nightlight greatly improved by a little hacking, and there are plenty more IKEA hacks where that came from.

Smart Pants Sound Alarm When Your Fly Is Undone

May 23, 2023 by Lewin Day 28 Comments

It’s always embarrassing to be told your fly is down. Even moreso when you realize it’s been that way since you returned from the bathroom an hour ago. [Guy Dupont] has built a device to solve this awkward issue once and for all. (Nitter)

Pictured: The Hall effect sensor and magnet attached to the zipper.

The pants contain a Hall effect sensor which has been attached inside the fly of the jeans, at the bottom of the zipper. The zipper pull itself was then fitted with a strong magnet, which triggers the sensor when the zipper is in the open position. An ESP32 in the pocket of the jeans is tasked with monitoring the sensor. If it detects that the zipper has been down for too long, it sends a notification to the wearer’s smartphone to zip up. We kind of wish they’d sound an ear-splitting klaxon, but that might draw undesired attention to the wearer.

Zipper position monitoring seems like a nightmare at first, but [Guy]’s hack shows us that it’s actually trivial with this method. The system does, however, add significant complication to what was previously a totally-analog pair of pants. Don’t expect “Big Jeans” to jump on this tech, as maintenance and waterproofing issues would likely make the hardware a pain to deal with in real life.

Plus, just imagine the frustration every morning. “Sorry, mate, not ready to head out yet – I’ve gotta pair my jeans with my smartphone.”

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