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Comment by donpdonp | Hacker News Reader

I have a pinetime and the form factor is great (until I lost the back plate, next one will be sealed). All the opensource activity around the watch is also great. The biggest drawback to me is only 64k of ram. Thats a Commodore64's worth of ram. The 240x240 screen is 57kbytes, it must have its own display ram.

Also NordicSemi never seemed to be particularly opensource friendly. I'm hoping for a future RISCV edition of this watch with more ram.

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Apache have a fully open source Bluetooth LE stack for most of the Nordic Semi chips, in part because they actually documented their radio hardware unlike most other manufacturers.

I think the linux foundation has one in zephyr as well.

Zephyr uses NimBLE

Exactly!

Do you state that it has its own display RAM or doesn't it?

240x240 is ~56.25 kB at 8 bpp. the screen is RGB 65K colors, that is, 16 bpp; so the framebuffer size should be twice larger. I assume that the display controller has its own memory. True, you would need another 112,5 kB for double-buffering, but maybe you can do without it.

Color displays are great, but they should have had an option for a (color or black and white) e-paper display. More efficient for these purposes imo.

I would pay so much for a hackable watch like this with a 3 or 4 color epaper display, I'd almost pay as much as an apple watch if it was high quality hardware and had a great open API and toolchain.

I'd pay more than for mass produced consumer gear, from any manufacturer.

Go on ebay and purchase a Pebble Time. Color epaper display, fully hackable even after being discontinued thanks to the dev community who continues to update it with "Rebble" the open source version of the OS it ran on.

Thanks!

ePaper is just their name for a transflexive LCD display. It's not eInk type technology

Yeah, the original Apple watch had like half a GB, and a raspberry pi zero ($5 price) has the same. Couldn't they have fit that within both budget and size?

It's a microcontroller rather than an application chip - so the amount of RAM will always be significantly less. A really beefy high end microcontroller might have 1MB of internal RAM - and for most applications that's more than enough.

Ohhhhh, I didn't realize that. Makes a lot more sense, I guess it is a better comparison to an Arduino than a raspberry pi.

> Couldn't they have fit that within both budget and size?

Oh they could have. The problem is: it's extremely hard to get access to powerful SoCs - the vendors simply won't work with you and most of the documentation is under NDA.

> it's extremely hard to get access to powerful SoCs - the vendors simply won't work with you

That's a really good point. I remember having the Pebble watch (this was pre-Apple and Android watches) and I think it had 128 KB of RAM total, including OS, background tasks, apps, etc. That was a mass produced and commercialized item though.

I've written about the other challenges in another post: https://news.ycombinator.com/item?id=25252022

Slapping on a more RAM on the PCB is not free energy-wise. The watch only has a 180mAh battery that needs to provide power for an entire week.

I mentioned in another comment about how I had the Pebble watch (before Apple and Android watches were a thing) and it had 128 kb ram total, but it lasted 11 days. That thing was a beast, but as someone else mentioned cost is a. big consideration too. It had 150 mAh on the newer models, before it was discontinued, so while I'm sure it definitely eats up energy I think it's definitely possible to fit more RAM in the power constraints.

Granted that was an e-paper display. (They had color and black and white options)

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