Smartwatch 10 Years Ultra-Long Battery Life

If your prototype is not held together by Kapton tape, sheer will and determination, you are holding it wrong.

I'm from the school of better get a working hack today than a perfect future design never.

After a whole hour of soldering and name calling it's here! I'm gonna wear this over thanksgiving and see if its a pterodactyl or a turkey.

Stay tuned for the next release.

Cheers!

The PCB works! Yeah! Revision 2 is a go!!!

I can program it and see the BLE on the app, the watch displays correctly, so the antenna and programmer connector and display connector are all correct. The PCB is dabomb!

Minor setback, the flex-cable for the external programmer doesn't connect for some reason, I guess there is some subtle manufacturing conflict of a flex cable, 80 micron trace and the wave solder process. I will look into it tomorrow, as I'm extremely tired, doing this after regular work hours is a recipe for disaster. The PCBs and components are so minute and fragile it's trivial to destroy a $200 PCB and a month of work with the slightest wrong move with my fat fingers.

I'll see if I could resolve the programmer connector tomorrow, there must be a simple reason, nothing a microscope and an X-Ray can't solve.

We are one step closer.

Cheers!

First assembly of Alpha Automata version (lol).

Solid stainless-steel body, anti-allergenic, anti-magnetic 316L (a.k.a. surgical steel).

Silicone strap.

Already see a number of problems, and some will need to be addressed way down in R5 (we are currently at R2).

Regardless, will report later with actual working version once I confirm PCB.

Cheers!

Exciting news, the R2 (actually that's R3 but I started counting from 0 so here we go) of the main board is here, will post pics later today (I have a full time job, you know :)

And R3 is also on the way for manufacturing, and I already started planning R4.

Cheers!

Sensor for depth measurements:

https://www.te.com/usa-en/product-MS583730BA01-50.html

https://www.digikey.com/en/products/detail/te-connectivity-measurement-specialties/MS583730BA01-50/5629501

30 bar/300m, 1uA, i2c

Seems like a winner, for only $14, will see if I can get a sample to add to the watch as a dive option.

While waiting to get things manufactured, and on/off working on the alarms, I also looked into a color LCD.

At 1Hz refresh rate, and 1Ah battery, assuming no other power draw, this is a 5uA display, which corresponds to about 22 year life. I see many problems here, most notably the need for well regulated 3.2 and 5.0 V dual power source, but that's for future consideration. Not bad, and definitely worth the next iteration if anyone would like to explore a color variant.

Ordered the PCB fully assembled, without going into details, will take up to a month to get it to my desk, this is not really a critical step of the design process, I can wait. If the tool is successful I'll open it for others to order.

I have a commercial nano-amp meter for that work but it's always cool to develop your own tools in the spirit of the fully self-contained design/development bootstrap effort.

I need to measure fast transient micro-current values, and found an abandoned project on eevblog:

https://www.eevblog.com/projects/ucurrent/

Thank you, Davy Jones! https://www.siliconchip.com.au/Issue/2009/April (awesome name BTW).

Got the schematics and during a long and boring meeting I had, I filled my time with making from scratch a replica for myself, as the module seems to be out of stock and not available anywhere else. I wanted to buy it but no luck, so making it it goes.

Ended up replacing some components, due to personal taste and general availability, and will try to manufacture soon. Perhaps biggest are the large capacity coin cell battery holder, and the massing 10mO grid sensing resistor to improve the error. In fact, I do have an advanced nano-Ampere meter, however, that's way too bulky and fancy for my taste. Also, not everyone could afford such tools, therefore, I will make that available perhaps as a separate satellite project for people to use if they need something like that.

Not bad for an hour work. Sometimes long and boring meetings do have an upside.

Cheers!

Revision 3 was submitted for technical audit and manufacturing, let's see how that goes.

It's a little bit of a routing mess due to the debugging connections, but all the important points are met.

-magnetometer/compass

-accelerometer/imu

-power-down

Stay tuned!

Re-arranged the entire PCB, re-routed and added a magnetometer and accelerometer, as well as an external means of power-down, which is actually pretty clever, might I say. Again, component selection, component selection, component selection... it's the key to success. Study hard kids, and spend all your time reading data sheets, instead of watching... haha.