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> does that mean that every time you hit a key (after the idle timeout) you have to wait 5 seconds for the pi to boot, wasting 5 more precious joules (a minute of active usage battery life at 100mW)

Yes, that's exactly the plan. Pi zero does not have suspend to ram unfortunately, hence this elaborate work around. Remember, the use case is a weekend chat device. This power management scheme fits the use case perfectly.

well, i agree that your chat message being delayed for 5 seconds is not critical

but waiting 5 seconds for a keystroke to be echoed (sometimes) is appalling. you would not get permission to do a user study from an irb. it would be denied on grounds of needless cruelty to experimental subjects

it would fit the use case perfectly if you had a low-power microcontroller that updated the screen in response to keystrokes, but what you're describing is a user interface design botched for no good reason

even the rp2040 would work for that at the weekend level

this is not quite a 'solar freakin' roadways' level of mistake because you could fix it with relatively minor tweaks to the design, but if you don't, you'll be left with a design that's unusable on battery, either because of battery life or responsiveness

fwiw i don't think restarting a computer in response to a keystroke is an elaborate workaround at all; that part of the design is perfectly reasonable

check out how mosh predicts keystroke effects for 'speculative local echo' and think about how you could do that on the rp2040 (or ideally an esp32 or apollo3 or something) while you're waiting on the giant linux behemoth to awaken from its slumber and restart gomuks or vim or whatever

I think you are misunderstanding the plan. The device will stay on until you turn it off, or 5 mins after last keystroke.

you say 'I think you are misunderstanding the plan. The device will stay on until you turn it off, or 5 mins after last keystroke.'

that's the plan i described yesterday in https://news.ycombinator.com/item?id=35983387

that's the plan i think will give you three hours of battery life: 2 amp hours times 3.7 volts divided by 2.5 watts gives 3 hours of use. 36 5-minute timeouts. do you have a different estimate? did i miscalculate?

that's not a weekend

in that comment i also explained an approach that would beat that by two orders of magnitude if you applied it with the same components (though there i supposed the hardware would use an esp32)

btw my grandparent comment https://news.ycombinator.com/item?id=35984332 is upvoted to 11 at the moment so evidently even if you think it's stupid your customers don't

if it doesn’t meet your needs, then don’t buy the device.

You use “customers” as if this were trying to be a full product. This is a weekend hack. Of course there’s going to be low-hanging fruit that could be optimized away.

Stop shitting on the guy’s earnest enjoyment. What you’re doing is akin to going to your favorite package’s issues tracker and making a P0 request like “rewrite it in rust, python sucks”

you seem to have skimmed the previous messages and misunderstood them

it's not a weekend hack, it's a commercial product, designed and built by a team of several people. the weekend hackers (or chatters) are the intended customers; they are not the makers. they have 50 prototype units in stock, and they're taking preorders for two more larger batches which they expect to ship in august and september. august is 70 days away, an interval which is 35 times larger than a weekend

the 'weekend' aspect is how long the user should expect it to work for, not how long they've spent on developing it

unfortunately, their current design seems to have a fatal flaw that renders it useless for its intended purpose, but one that's easily fixed

my comments are not shitting on it; they explain how to fix it, providing information the original designers were evidently unaware of, so that they can ship a product that fulfills its intended purpose, which would probably make them a few tens of thousands of dollars. up to them if they want to do it or not; i'm not an investor. if they don't, probably someone else will

i could of course be mistaken about this, but so far there's no reason to suspect that i am; the pushback in comments here has all been ego-driven posturing like 'This power management scheme fits the use case perfectly.' instead of something like 'actually i have a rp2040 deep-sleeping at 100 microwatts' or 'i have this pi zero w running at 700 milliwatts with such-and-such a kernel config so actually they'll get 12 hours of battery life'

You've just described a Playdate. It's a game console not a computer but it pretty much is designed how you've suggested. It also uses the same Sharp Memory LCD.

it's the sensible way to design a system around this display, but the playdate isn't what i'm looking for because it doesn't have a keyboard and also it's kind of bulky

I'll have you know my fragile monster of a razer phone 2 has survived being dropped more often than I can count XD

the razer was way lighter and less glass-intensive than currently popular phones

but what's a razer 2