Cheap Smartwatch Hacking, To Run Your Own Code

May 2, 2020 by Al Williams 38 Comments

[Aaron Christophel] has been busy, he picked up a P8 smartwatch of the type that many of you will no doubt have seen. They cost almost nothing and do almost… nothing. In all fairness, they do connect to your phone using Bluetooth LE courtesy of a chip from Nordic (the NRF52832), and they can do several simple tasks. But they don’t run applications in the way an Android or Apple watch does. [Aaron] wants to run his own applications, so his YouTube channel has a lot of information about hacking the P8 and other watches with similar chips. In one video you can watch below, he demonstrates how he’s written support for Arduino programming to the devices. What we were really excited about was the second video below where he shows his Android app that can flash the devices via Bluetooth. That means you can potentially hack these devices without opening them up.

The app that normally runs these watches is called Da Fit, so [Aaron] called his utility DaFlasher. This is all early stuff so we expect some coaxing to get everything working, but it has great promise.

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SMA-Q2 Smart Watch Is Completely Hackable

January 30, 2020 by Danie Conradie 30 Comments

The search for the ultimate hacker’s smart watch probably won’t end any time soon. [emeryth] has nominated another possible candidate in the form of the SMA-Q2, and has made a lot of progress in making it accessible.

Also known as the SMA-TIME, the watch is based around the popular NRF52832 Bluetooth SoC, with a colour memory LCD, accelerometer, and a heart rate sensor on the back. The main feature that makes it so easy to hack is the stock bootloader on the NRF52832 that works with generic Nordic upload tool, making firmware upgrades a breeze via a smart phone. Unfortunately the bootloader itself is locked, so it must be completely wiped to gain debugging access. The hardware configuration has also been well reverse engineered with all the details available.

Custom main board with a NRF52840 module

[emeryth] has most of the basic features working with his custom firmware, although it’s still in the early stages. He designed a new watch face that includes weather updates and basic audio controls. The 3-bit display’s power consumption has also been reduced by only refreshing the necessary parts. The heart rate sensor outputs the raw waveforms, and it’s pretty accurate after a bit of FFT and filtering magic. Built-in tap and tilt detection is available on the accelerometer, which works well, but strangely doesn’t appear to have been used in the stock firmware.

Unfortunately the original enclosure design that used screws was dropped for glued version. It’s still possible to open without breaking anything, just a bit more difficult. ~~[emeryth]~~ Another hardware hacker named [BigCorvus] has even designed a completely new open-source main board with a NRF52840 module and heart rate sensor on a small flex PCB, with everything up on GitHub.

We really hope the community takes a liking to this watch, and look forward to seeing some awesome hacking. This is an excellent addition to the list of candidates for the perfect hacker’s smart watch that [Lewin Day] has already investigated . We also see a lot of DIY smart watches including one with a beautiful wood-filled 3D printed housing and another with LED matrix display.

Neat Smart(ish) Watch Build Uses BLE

June 17, 2019 by Richard Baguley 6 Comments

Digital watches are a pretty neat idea, and are a great way to experiment with designing and building low-power circuits. That’s what [Eric Min] did with this neat smart watch build. It’s based around an nRF52832 SoC that does all of the heavy lifting, including connecting to a smartphone to get the time when the battery is replaced. It also has a decent quantity of blinky LEDs, which is important on any project of this type.

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Roll Up Your Sleeve, Watch A Video With This Smart Watch Forearm Projector

April 25, 2018 by Dan Maloney 35 Comments

We’re all slowly getting used to the idea of wearable technology, fabulous flops like the creepy Google Glass notwithstanding. But the big problem with tiny tech is in finding the real estate for user interfaces. Sure, we can make it tiny, but human fingers aren’t getting any smaller, and eyeballs can only resolve so much fine detail.

So how do we make wearables more usable? According to Carnegie-Mellon researcher [Chris Harrison], one way is to turn the wearer into the display and the input device (PDF link). More specifically, his LumiWatch projects a touch-responsive display onto the forearm of the wearer. The video below is pretty slick with some obvious CGI “artist’s rendition” displays up front. But even the somewhat limited displays shown later in the video are pretty impressive. The watch can claim up to 40-cm² of the user’s forearm for display, even at the shallow projection angle offered by a watch bezel only slightly above the arm — quite a feat given the irregular surface of the skin. It accomplishes this with a “pico-projector” consisting of red, blue, and green lasers and a pair of MEMS mirrors. The projector can adjust the linearity and brightness of the display to provide a consistent image across the uneven surface. An array of 10 time-of-flight sensors takes care of watching the display area for touch input gestures. It’s a fascinating project with a lot of potential, but we wonder how the variability of the human body might confound the display. Not to mention the need for short sleeves year round.

Need some basics on the micro-electrical mechanic systems (MEMS) behind the pico-projector in this watch? We’ve got a great primer on these microscopic machines.

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Inventing The Digital Watch Again And Again And…

March 19, 2018 by Steven Dufresne 94 Comments

In the 1950s, artwork of what the future would look like included flying cars and streamlined buildings reaching for the sky. In the 60s we were heading for the Moon. When digital watches came along in the 70s, it seemed like a natural step away from rotating mechanical hands to space age, electrically written digits in futuristic script.

But little did we know that digital watches had existed before and that our interest in digital watches would fade only to be reborn in the age of smartphones.

Mechanical Digital Watches

Cortébert jump-hour wristwatch by Wallstonekraft CC-BY-SA 3.0 — Cortébert jump-hour wristwatch.
Image by Wallstonekraft CC-BY-SA 3.0

In 1883, Austrian inventor Josef Pallweber patented his idea for a jumping hour mechanism. At precisely the change of the hour, a dial containing the digits from 1 to 12 rapidly rotates to display the next hour. It does so suddenly and without any bounce, hence the term “jump hour”. He licensed the mechanism to a number of watchmakers who used it in their pocket watches. In the 1920s it appeared in wristwatches as well. The minute was indicated either by a regular minute hand or a dial with digits on it visible through a window as shown here in a wristwatch by Swiss watchmaker, Cortébert.

The jump hour became popular worldwide but was manufactured only for a short period of time due to the complexity of its production. It’s still manufactured today but for very expensive watches, sometimes with a limited edition run.

The modern digital watch, however, started from an unlikely source, the classic movie 2001: A Space Odyssey.

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Make A Smart(ish) Watch From An Old Cell Phone

July 19, 2016 by Richard Baguley 7 Comments

Looking for a fun junk box hack? Have one of those old Nokia phones that (in contrast to your current smartphone) just won’t give up the ghost? Tinkernut has a nice hack for you: making a smart watch from an old cell phone. Specifically, this project details how to make a smart watch that displays time, date, incoming calls and texts from a Nokia 1100 cell phone display and a few other bits.

This 3-video series covers how to extract the display, connect it to an Arduino and conecting that to an Android phone over Bluetooth. We’ve seen a few similar smart(ish) watch builds, but this one covers the whole process well, including building the Android app in the MIT AppInventor. Sure, the final result is not as polished as an Apple Watch, but it’s a lot cheaper and easier to hack…

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Smart Sweatbands

February 21, 2016 by Al Williams 32 Comments

If you’ve ever known anyone who has to monitor their blood glucose level, you know it is annoying to have to prick your finger with a lancet to draw blood for each measurement. A new sweatband that incorporates flexible electronics can measure glucose–as well as sodium, potassium, and lactate–from your sweat, without a painful pin prick.

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