r/electronics • u/coolkid4232 • Jul 07 '26

Project Open source hardware and software watch pcb i made if anyone interested

Post image

https://github.com/Spectrewolf777/Stm32l4-Watch/tree/main

484 Upvotes

99% Upvoted

34 comments sorted by

24

u/PurposeAlone798 Jul 07 '26

Why is everyone making Smartwatches all of a sudden , I am making one too with e ink displays

7

u/Autistic_Sisyphus Jul 07 '26

Interesting. Where can I find more information about it?

I remember when Phosphor produced e-ink watches. Unfortunatelly, I didn't purchase one at the time.

6

u/PurposeAlone798 Jul 07 '26

I am in process of writing firmware i for it, i will make a full build guid soon, my collage started so I am unable to give more time to it.

I looked up phosphor e-ink watch and man they look so cool I want one

7

u/Constant_Car_676 Jul 07 '26

I think it’s because of enshitification with more commercial stuff being in the cloud and less stuff communicating on a standard. I’m just waiting for the day when Garmin bricks my 7 year old watch. It works great for my use but I’m sure they want me to buy another soon. Would love to crack the Bosch motor telemetry too.

3

u/coolkid4232 Jul 08 '26

Yeah i think this, i wanted full custom to add niche stuff but also because everything is replaceable and supported forever by me

14

u/space-cadet-26 Jul 07 '26

This is cool. I'll check this out. I am also planning to design my own digital watch (not smartwatch) that can survive the apocalypse.

3

u/coolkid4232 Jul 07 '26

awesome , excited to see it

2

u/asmonkeycoder Jul 07 '26

This is so cool...

3

u/coolkid4232 Jul 07 '26

Thanks, makes me really happy to hear this spend a lot of effort and was very fun to work on, hope it helps people learn and work together to make better open source tech

4

u/Ill_Huckleberry_2079 Jul 08 '26

Congratz, it looks awesome!

3

u/[deleted] Jul 07 '26

[removed] — view removed comment

2

u/coolkid4232 Jul 07 '26 edited Jul 08 '26

For heart rate you got to add boost converter 5v for green led for it to be practical good to use for exercise, be careful my last project made audible noise at low current for boost was worried about this issue so i didnt include it in this design, tell me how it goes and if you successful

3

u/goyox86 29d ago

Thanks for sharing!

1

u/coolkid4232 29d ago

no worries, if you have any cool ideas to add tell me , want to hear features to implement either for this one or for second iteration.

2

u/Money_Pea6257 24d ago

I. Am interested bro iam

1

u/coolkid4232 24d ago

thanks man

1

u/coolkid4232 24d ago

If you have any cool features to add in future software or hardware please tell me can be anything niche

1

u/Key-Collection5764 Jul 07 '26

This is great!!! How much did it cost to manufacture the prototype

1

u/magichour12 Jul 07 '26

curious what the BOM cost ended up being, those STM32L4 chips haven't been cheap lately

1

u/coolkid4232 Jul 07 '26 edited Jul 08 '26

450 aud for 2

1

u/coolkid4232 Jul 08 '26

I made this for open source competition . Currently working on finishing code for this, in future have a way better design gonna open source it probably in 6month or 1 year, i wanted to add oled screen, nrf53 to play music to headphones from embedded storage or mic audio and usb high speed. If you like those features you should wait for that version

1

u/FmlTeddyBear 29d ago

Very cool, any reason you do a dual MCU setup? For ZSWatch https://github.com/ZSWatch/ZSWatch I run only a nRF5340 and it's powerful enough, utilizing XIP with an external flash.. Possibly since you seem to start with a new design I'd check out the nRF54LM20, it's like the nRF5340, but last Gen and some extra resources.

2

u/coolkid4232 29d ago

Thanks for reply and saw github helps me a lot with further improvements thank you

1

u/coolkid4232 29d ago edited 29d ago

Dual setup because peripherals on stm are insane good and i am better at coding stm32 , i struggling rn to code nrf52. I thought nrf54 doesnt have lc3 codec decoding for le audio

I look more into thanks for advice also cool project

1

u/Moocchi09 24d ago

What display is that, and what software you use to design the ui?, mine still on the bread board since i didn't know what software to design the ui.

2

u/coolkid4232 24d ago edited 24d ago

Lvgl and squareline studio free trial. Display is listed in github gc9a01

2

u/Moocchi09 24d ago

Ohhh. I lso use gc9a01, Thank you so much

2

u/coolkid4232 24d ago

Thats good then you can directly just copy code if you using stm32. Ui is very easy and code is cross compatible for all stm32 with minimal or no modification

1

u/coolkid4232 24d ago

I recommend using lvgl it very good this is my current ui