Reverse Engineering A Very Cheap Fitness Band

July 8, 2021 by Zoe Skyforest 10 Comments

With the rise of big-name smartwatches in the marketplace, there are also a smattering of lower-end offerings. The M6 fitness band is one of them, and [Raphael] set about hacking the cheap device with a custom firmware of his own creation.

The M6 band, which sells for around $6, appears to trade on name similarity to the more expensive (~$50) Xiaomi Mi Smart Band 6 fitness tracker. Upon disassembly, [Raphael] found that the system-on-chip running the show is a Telink TLSR8232. It’s paired with a 160×80 display, a small LiPo battery for power, and a vibration motor and what appears to be a fake heart rate sensor.

[Raphael] wanted to flash the SOC with a new firmware, and learned a lot from code for a similar part created by [atc1441]. It took some time to figure out how to program the chip using the somewhat oddball SWire interface, but [Raphael] persevered and eventually got things going after much research and experimentation.

From there, it was yet further work to figure out how to read the capacitive button input as well as how to drive the screen, but [Raphael] succeeded in the end. The final result was whipping up a firmware that allowed him to read Bluetooth Low Energy soil moisture sensors he has installed in his plants at home.

It’s not [Raphael], aka [rbaron]’s first bite at the cherry; we’ve featured his efforts in hacking similar fitness bands before! Video after the break.

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Forget Smart Watch; Build A Smart Hat

June 21, 2021 by Al Williams 4 Comments

Smart watches are pretty common today, but how many people do you know with a smart hat? [Oliver] built Wilson which he bills as “the IoT hat.” We wonder if the name was inspired by the Home Improvement character of the same name who only appeared as a hat above the fence line. You can see a video of the project, below.

The project is pretty straightforward for hardware. An LED strip, an Arduino, and a Bluetooth module. Oh. And a hat. The software, as you might expect, is a bit more complex. It allows you to display SMS messages to your hat.

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The Future’s So Bright, You Gotta Wear Arduglasses

March 25, 2021 by Tom Nardi 21 Comments

Tiny OLED displays are an absolute must-have in the modern parts bin, so what better way to show your allegiance to the maker movement than with a pair of Arduino-compatible OLED glasses? Created by Arduboy mastermind [Kevin Bates], these digital spectacles might not help you see any better — in fact, you’ll see a bit worse — but they’ll certainly make you stand out in the crowd at the next hacker con. (Whenever we can have one of those again, anyway.)

The key to this project is a pair of transparent CrystalFonts OLED displays, just like the ones [Sean Hodgins] recently used to produce his gorgeous volumetric display. In fact, [Kevin] says it was his success with these displays that inspired him to pursue his own project. With some clever PCB design, he came up with some boards that could be manufactured by OSH Park and put together with jewelry box hinges. Small flexible circuits, also from OSH Park, link the boards and allow the frames to fold up when not being worn.

The Arduglasses use the same ATmega32U4 microcontroller as the Arduboy, and with a few basic controls and a small 100 mAh rechargeable battery onboard, they can technically run anything from the open source handheld’s extensive software library. Of course, technically is the operative word here. While the hardware is capable of playing the games, [Kevin] reports that the OLED displays are too close to the wearer’s eyes to actually focus on them. That said the ability to easily create software for these glasses offers plenty of opportunity for memes, as we see in the video below.

For reasons that are probably obvious, [Kevin] considers the Arduglasses an experiment and isn’t looking to turn them into a commercial product or kit. But if there’s interest, he’s willing to put the design files up on GitHub for anyone who wants to add a pair of Arduino glasses to their cyberpunk wardrobe.

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Fire In The Palm Of Your Hand

January 29, 2021 by Danie Conradie 15 Comments

For as long as super-heroes have existed, they have inspired hacker projects. For [Everett Bradford], emulating the character Pyro from X-Men has been an on and off project for the last decade. His latest version, Pyro System V4, integrates quite a bit of control electronics to give the rather convincing effect of mind-controlled fire in the palm of his hand. (Video, embedded below.)

The system is a motor-actuated slider strapped to [Everett]’s forearm, which pushes a pivoting end-effector with an integrated butane burner into the palm of his hand. The slider runs on 4 mm linear bearings actuated by a small geared DC motor using cables. The end effector is spring-loaded to push it into the palm and integrates a high voltage ignition arc generator circuit, nozzle, and capacitive activation button.

The butane gas canister and the valve was cannibalized from a small blow torch lighter, and the valve is actuated by another geared DC motor. The valve actuator, slide actuator, and end-effector hinge all integrate position feedback via hall effect sensors and magnets. The sensor in the hinge allows the slide to actively correct for the angle of the user’s wrist, keeping the end effector in the middle of the palm.

The control circuit is split into two parts. One PIC16 microcontroller runs all the motion control and position sensing, while a PIC18 connected to a small touch screen handles user interface, control parameters, and ignition. The touch screen proved especially useful for control parameters during development without needing to connect to a laptop.

Some of [Everett]’s previous version had a much more impressive (and dangerous) flame but was also very bulky. We think this latest version strikes a pretty good balance regarding compactness and achieving convincing illusion.

[Colin Furze] is another name commonly associated with fire-breathing contraptions, but they have a proven history of landing him in hospital.

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Circuit Boards You Can Stretch: Liquid Metal Nanomaterials Make A Strange Flex

November 19, 2020 by Dan Maloney 9 Comments

If you think polyimide-based flexible PCBs are cool, wait until you get a load of what polymerized liquid metal networks can do.

Seems like [CNLohr] has some pretty cool friends, and he recently spent some time with a couple of them who are working with poly LMNs and finding out what they’re good for. Poly LMNs use a liquid metal composed of indium and gallium that can be sprayed onto a substrate through a laser-cut stencil. This results in traces that show the opposite of expected behavior; where most conductors increase in resistance when stretched, pol LMNs stay just as conductive no matter how much they’re stretched.

The video below shows [CNLohr]’s experiments with the stuff. He brought a couple of traditional PCB-based MCU circuits, which interface easily with the poly LMN traces on a thick tape substrate. Once activated by stretching, which forms the networks between the liquid metal globules, the traces act much like copper traces. Attaching SMD components is as simple as sticking them to the tape — no soldering required. The circuits remain impressively stretchy without any apparent effect on their electrical properties — a characteristic that should prove interesting for wearables circuits, biological sensors, and a host of real-world applications.

While poly LMNs aren’t exactly ready for the market yet, they don’t seem terribly difficult to make, requiring little in the way of exotic materials or specialized lab equipment. We’d love to see someone like [Ben Krasnow] pick this up and run with it — it seems right up his alley.

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Seek And Ye Shall Command

October 2, 2020 by Brian McEvoy 3 Comments

If we count all the screens in our lives, it takes a hot minute. Some of them are touchscreens, some need a mouse or keyboard, but we are accustomed to all the input devices. Not everyone can use the various methods, like cerebral palsy patients who rely on eye-tracking hardware. Traditionally, that only works on the connected computer, so switching from a chair-mounted screen to a tablet on the desk is not an option. To give folks the ability to control different computers effortlessly [Zack Freedman] is developing a head-mounted eye-tracker that is not tied to one computer. In a way, this is like a KVM switch, but way more futuristic. [Tony Stark] would be proud.

An infrared detector on the headset identifies compatible screens in line of sight and synchs up with its associated HID dongle. A headset-mounted color camera tracks the head position in relation to the screen while an IR camera scans the eye to calculate where the user is focusing. All the technology here is proven, but this new recipe could be a game-changer to anyone who has trouble with the traditional keyboard, mouse, and touchscreen. Maybe QR codes could assist the screen identification and orientation like how a Wii remote and sensor bar work together.

E4 Empatica device for measuring location, temperature, skin conductance, sleep, etc. on arm

Choosing The Optimal Sampling Rate For Your DIY Heart Rate Monitor

September 3, 2020 by Orlando Hoilett 19 Comments

With wearables still trying to solidify themselves in the consumer health space, there are a number of factors to consider to improve the reliability of such devices in monitoring biometrics. One of the most critical such parameters is the sampling rate. By careful selection of this figure, developers can minimize errors in the measurement, preserve power, and reduce costs spent on data storage. For this reason, [Brinnae Bent] and [Dr. Jessilyn Dunn] wanted to determine the optimal sampling rate for wrist-worn optical heart rate monitors. We’ve shared their earlier paper on analyzing the accuracy of consumer health devices, so they’ve done a lot of work in this space.

The results of their paper probably don’t surprise anyone. The lower the sampling rate, the lower the accuracy of the measurement, and the higher the sampling rate the more accurate the measurement when compared to the gold standard electrocardiogram. They also found that metrics such as root mean square of successive differences (RMSSD), used for calculating heart rate variability, requires sampling rates greater than 64 Hz, the nominal sampling rate of the wearable they were investigating and of other similar devices. That might suggest why your wearable is a bit iffy when monitoring your sleeping habits. They even released the source code for their heart rate variability analysis, so there’s a nice afternoon read if you were looking for one.

What really stood out to us about their work is how they thoroughly backed up their claims with data. Something crowdfunding campaigns could really learn from.