Bangle.js v2 - Hackable Javascript Smart Watch (ADA5427)

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Bangle.js 2 is an open, hackable smartwatch. With a sunlight-readable always-on screen, 4-week battery life, complete flexibility, and complete control of…

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I went to install my first app, but it said there was a firmware update available.
I installed that, but it appears to have failed and is not in an endless DFU loop. I’ve tried everything I can find on the web, including the nRF apps on ios and android.

The fix was to use the DFU Firmware Update app. I set the packet count to 1, so it wouldn’t break up to multiple packets & it worked. That took 57 million attempts and variations to discover.

But it’s working now for anyone else facing the same issue


Hi Cheese,

Many thanks for sharing, I am sure your fellow makers are absolutely going to appreciate this.

Bangle.js 2 is a refreshing break from expensive smart watches

By costing as much as the more expensive ones?

I’m kind of tempted to try one of those ones I can get for close to ten bucks… It’d be a no-brainer if I knew I could flash a custom ROM.

Although what would be a refreshing change from every other smartwatch is a thickness of 6mm or less. This one is double that, like most of them…

Hi Kimmo,

I see what you mean about the price point compared to some cheaper watches available, though I believe in this page its referring to significantly more expensive digital watches such as those sold by Apple, Samsung and more high end tech companies which have capabilities similar to a smartphone.

In comparison to those watches, this product can be programmed to behave in a similar way to those at a significant price reduction.

Nevertheless if you do end up getting a cheap watch and programming it yourself, it would be great if you could put up a post about it, as I think everyone would be very interested to see how it goes.


I have a cheap smartwatch on the way from Temu: it was like 22 bucks. You can find them for as low as $7!

But as for something a bit more decent, I realised I had a unicorn sitting in a drawer… A Casino DBX-100 from 1988, the only Data Bank Casio they ever made with a full dot matrix screen. Unfortunately the alphanumeric button pad on the front of them was made of stuff that didn’t survive the years, so I’ve bought a dead example of a later model with a more durable button pad… Gonna be quite the challenge to transplant it.


Hi Kimmo,

That is a beast of a watch. Good luck on the transplant, I am sure that every time you check the time on that you will be reminded of how rewarding it was fixing it.

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Actually there were a couple of other Casios with dot matrix screens, now that I’ve been down that rabbit hole…

Here’s the current state of my DBX-100:

Oh yeah, the Temu smartwatch turned up; it was actually less than nine bucks. It is of course, janky AF. Still pretty awesome for the price, though… But as long as smartwatches have to be this thick, I’m just not interested. This one is relatively good at 12.3mm…

Properly thin watches are far too rare, and stupidly underrated. The Casio is 7.5mm; pretty stoked with it. Looking forward to this parts watch turning up around the end of January; it was like 30c postage from India…

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Hi Kimmo,

That’s pretty impressive price hunting. Let us know how you go reprograming the Temu watch.

If you had the time, maybe you could create a sperate topic on your Casio watch project. I think everyone is very excited to see how it goes.