Now we have all been tempted at one time or one other by the ultra-cheap electronics, often manufactured in China, which might be obtainable on websites like AliExpress. The costs are sometimes so low that the offers appear too good to be true. As YouTuber Poking Expertise not too long ago discovered, generally the offers are the truth is too good to be true. But even nonetheless, if you’re prepared to place in some work and settle for the shortcomings, the gadgets may very well be price choosing up anyway.
Poking Expertise purchased a smartwatch for about three {dollars}. The shiny display screen and slick design makes this stuff look very interesting, particularly contemplating the low worth. However when examined, it was discovered that in actuality the performance was significantly missing, the battery life was horrible, and the person interface was a nightmare. Worse but, the few sensors that have been obtainable appeared to be faux. The step counter added tons of of steps whereas sitting on a desk, and the center price/blood strain sensor all the time appeared to offer about the identical measurements.
A glance contained in the case (📷: Poking Expertise)
You get what you pay for, it appears. Poking Expertise determined to do a teardown to see precisely what was happening with this smartwatch. It turned out that the so-called coronary heart price sensor was simply an LED, and the spot for the precise chip was unpopulated on the PCB. The spot for the accelerometer that may energy the step counter was equally unpopulated. About all that was actual was a Telink TLSR8232 microcontroller, the show, and a vibration motor.
That isn’t so much, however but given the shape issue, it’s one thing one can work with. Poking Expertise thought that if this factor ran MicroPython, the horrible interface might be eliminated, and a person might program it to do one thing that’s really helpful. It might not be something revolutionary, however for 3 bucks or so, it might be a steal.
After going by a protracted and painful means of attaching the inner parts of the watch to a customized breakout board, then dumping and writing the flash with a customized Raspberry Pi Pico-based debug interface, Poking Expertise was a lot of the method there. However to develop new firmware for the onboard Telink microcontroller, a great deal of work was nonetheless wanted.
Profitable reprogramming with a Pico (📷: Poking Expertise)
The microcontroller didn’t include an Arm CPU core, as you’ll in all probability count on, however some unusual, proprietary processor as a substitute. And that meant a growth toolchain particular to this microcontroller needed to be put in and discovered earlier than going any additional. After slogging by that work, the job of porting MicroPython turned out to be fairly straightforward. Inside an hour an preliminary model was up and working, however after all there was extra work to observe to clean out some tough edges. When all was stated and finished, MicroPython labored positive with the 16 kilobytes of RAM and weird structure of the Telink chip.
Whereas the watch solely value just a few {dollars}, the engineering effort was in all probability price hundreds, so was it price it? Effectively, not for Poking Expertise, except you rely it as an academic train. However for these of us that may simply borrow that work and have a MicroPython watch very quickly, the three {dollars} is properly price it. Check out the complete video for an in-depth teardown of this junky and pretend, but nonetheless cool in some methods, smartwatch.