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Hey HN! This is my project. Hope you find it interesting. AMA.
by reerdna 4y ago
Hey HN! This is my project. Hope you find it interesting. AMA.
- upghost 4y agoHell yeah that’s some next level lisp hacking! Great work.
- reerdna 4y agoThanks! Have not had the chance to do too much lisp hacking yet though, I still very much consider myself a beginner. Mostly solder and C so far, apart from implementing a crude text editor.
- Rediscover 4y ago> Mostly solder and C... Hey! I used to have those two and assembly on my resume as the only entries under "Programming Languages" ! Very nice project.
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- keithwinstein 4y agoThis is awesome! This kind of extreme low-power application was the original reason I wanted Mosh -- I always thought it would be awesome to have a wireless (hand-cranked?) laptop that could run SSH and would only consume energy when (a) a key was pressed [to update the locally generated UI], or (b) it wanted to fire up the radio (on its chosen schedule, e.g. <1 Hz) to retrieve an update from the server of the "ground truth" UI and reconcile that with the local prediction.
- reerdna 4y agoThank you! Mosh is great, I have found it very helpful at times in my day job. SSHing into servers in Australia from Norway, the latency was pretty bad. Have not started working on wireless yet but I hope to get to it. The SoC i use has Bluetooth. Using it for a remote shell would be amazing.
- sitkack 4y agoThat is such a nerdy wholesome story. Definitely will have to make an eInk, foot treadle powered laptop that runs Scheme and uses Mosh.
- maxk42 4y agoHi there! Neat project! Can you give us a rundown of some of its features? Which processor are you using? Do you intend to sell these or are you only creating a prototype?
- reerdna 4y agoThank you! Not many features of note - it runs arbitrary lisp code, has a simple graphics interface. You can save and load code and data/text files to SD card. The processor is the Ambiq Apollo3 Blue, which is really what makes running arbitrary code with such low power consumption possible. 48/96MHz, 384k of RAM. https://ambiq.com/apollo3-blue/ https://ambiq.com/apollo3-blue/ There's an Apollo4 which is faster and has way more memory, but it's a tiny BGA chip which doesn't have an Arduino core and I don't have the skills to work with that (yet ...) I hope to create a PCB for it at least, it would make the device tiny and sleek and make it a lot easier for others to reproduce. But I haven't been able to learn PCB design yet.
- aidenn0 4y agoThe Apollo4 can also attach QSPI SRAM which could allow adding more RAM and perhaps allow running common lisp...
- kragen 4y agoAvailable QSPI SRAMs seem to consume a lot more power than the Apollo4 or Apollo3 itself, and because they're also slower, they increase the processor's duty cycle, which makes it use more power itself (except when the user is waiting on it, I guess, or you're running a background compute task).
- zrobotics 4y agoI'm not a professional, but have done some pcb layout for hobby projects. Are you looking for collaborators, or are you wanting to keep this a personal project? If so, I can be reached at my username@(googles mail platform). One other thing, I don't see the stl/cad files for the case anywhere, I assume you're still iterating on that. Very cool project!
- sophacles 4y agoI find it amusing that this computer you built has better specs than the first family pc my parents bought us in the 80s.
- reerdna 4y agoAs do I. We had a 286 which this would easily outperform. It could probably run DOOM (with dithering) quite well if someone put their mind to it.
- Narishma 4y agoI doubt it. It only has 384 KB of RAM.
- kragen 4y agoApparently the original Doom required 4 MiB of RAM https://old.reddit.com/r/gaming/comments/a4yi5t/original_doom_system_requirements_from_my_25_year/ https://old.reddit.com/r/gaming/comments/a4yi5t/original_doo... but I'm pretty sure there have been ports to platforms that had less.
- moring 4y agoMost of that is static data, so if stored unpacked, a larger flash should be sufficient to make the game need very little RAM. Unfortunately, if I read it correctly, this one only has 1MB of flash. (oh: but SD card. That could work!)
- kragen 4y agothanks! these are good points! however, if you have the sd card powered on all the time it will cut your battery life by about a factor of 30
- goosedragons 4y agoYeah, most of the 90s home console ports were to systems that had less than 4MB RAM. Jaguar, 3DO, PlayStation, SNES, 32X. The GBA also has less than 512KB RAM and a 16MHz ARM and had Doom and Doom II ports. Some cutbacks might be necessary but probably doable.
- RedNifre 4y agoDo you think this could work well in the form factor of a programmable calculator?
- reerdna 4y agoYes. A smaller, but higher resolution display is available from Adafruit, and they made a calculator tutorial for it which helped me a lot in the beginning: https://learn.adafruit.com/diy-rpn-desktop-calculator-with-circuitpython https://learn.adafruit.com/diy-rpn-desktop-calculator-with-c...
- megaman8 4y agoi love the minimalist concept of a laptop with so much battery life: Dell and Apple could learn something from this. so that gray piece on the right is the solar collector, right? since it can go 2 years, what's to stop it from going forever? what if you added a 2nd collector on the left? how big would the solar panel need to be in order for it to run indefinitely? Super job!
- reerdna 4y agoThanks! The biggest obstacle to running forever may be the chemistry of the li-poly battery which has a relatively low number of charge cycles and is known to degrade over time. A promising option is li-ion capacitors or supercapacitors, which I'm looking into. This is the board I've purchased for testing. https://www.tindie.com/products/jaspersikken/solar-harvesting-into-lithium-ion-capacitor/ https://www.tindie.com/products/jaspersikken/solar-harvestin...
- TylerE 4y agoWould it be possible to use standard 9v rechargeable cells? I’m sure the lifetime would be even less, but if a battery swap cost $10 and could be found at any corner drug store…
- dragontamer 4y agoId just personally go with replaceable parts. AA NiMHs are like $1 to $2 these days, and 6V 5Ah lead acid is like $20 (Lol, first hit on google is $4 from some no-name brand). Replace the battery every few years and you're set. Rely upon mass production, standard part numbers and highly recyclable parts (lead acid wins at this). ------- Lead Acid is particularly good at UPS style power usage patterns. It's very easy to perpetually trickle charge lead acid. ------ If you're set on Li-ion, then use a standard 18650 cell, so you know that you'll always be able to buy a replacement. But given the attributes I see here, lead acid probably wins. So you have to replace a part every 3 years that costs $5 to $10, big whoop.
- lll-o-lll 4y ago
- dragontamer 4y agoCPU -- we all have opinions on uCs. I see that your chosen uC has very low active power consumption, less than 10uA per MHz, suggesting under 1mA full tilt. Have you run any tests to see if active mode is indeed the mode you're in most of the time? Or is it possible that other uCs that could have better sleep current can beat your uC of choice? Screen -- I like the Sharp in pixel memory LCD screens, though 4 inches is a bit small. A bigger screen would be what I'd be searching for, but I also know that monitors use a surprising amount of power, and 4 inches is the biggest memory-LCD screen in my area as well. E-ink, for all of it's faults, does climb to 7+ inches and beyond. But changing eink screens is surprisingly power hungry. Bluetooth -- lol, there goes the power budget!! This uses what? Probably 10x more power than everything else combined? I/O is a necessity and it's a good feature, but I really do wish* it used less power.
- bee_rider 4y agoI wonder if a combination of eInk and pixel memory LCD could be good? Use them as two monitors, keep vim on the LCD, web browser or other documentation on the bigger eInk.
- kragen 4y agoThe Barnes & Noble Nook did this, except that they were using a conventional backlit color active-matrix LCD rather than a memory-in-pixel LCD like this. There is clearly a crossover point at which this combination would use lower power, because the e-ink display uses zero power when not updating, and the memory-in-pixel LCD uses power even to retain the display. So as the update rate goes low enough, at some point the e-ink display will use less power. My vaguely remembered estimate of this crossover point is that the e-ink display starts using less power than the memory-in-pixel LCD when the update rate is less than about one update per hour.
- rerdavies 4y agolol
- canadianfella 4y ago
- LennyHenrysNuts 4y agoI love this. Thank you.
- torgoguys 4y agoI've been working on a similar project and if you're up for it, would love to talk to you in more depth about your project if you're game. I've been eying up the newer Apollo4 (having recently ordered the devkit to experiment with). My email is in my profile if you'd like to chat and trade information, ideas, or collaborate.
- mannanj 4y agoWondering if you specced out or thought of an implementation with a e-ink display and internet. How long can battery last for that base spec, with say 10", 13" models?
- bhtru 4y agoVery cool project. 2 questions: 1. How did you find working with the Sharp Memory display as a tinkerer? Did you like building with it and would you recommend it? It's pretty new tech to me and I've been mulling whether to splurge for it for a potential pet project of mine. 2. How's the refresh rate on it? Judging from your video it looks pretty dang swell. It looks to be a lot faster than the typical 15hz one sees on higher end e-ink displays available right now.
- andreer 4y agoUsing the Adafruit breakout board, I had no problems other than an SPI bug in the Arduino core. Be warned that they are fragile when not protected, I sheared off the flex cable on one which was not fun. Official refresh rate is ~25 hz, unofficially they seem to be able to go a lot faster (2-3X) if you don't mind increasing power consumption. And it's faster if you update only some lines. But by then you have run into a limitation in how fast the liquid crystal can respond.
- airbreather 4y agocan you get a display with same technology but larger?
- GabeIsko 4y agoHave you ever been tempted to build a giant cyberpunk style magnifying glass into the computer to make the screen bigger?
- no_identd 4y agoEver hear of ChrysaLisp?