However, I was immediately curious about how the "dual battery" feature works. The IP5306 power-management IC seems to be designed only for a single battery, and as far as I can tell from the schematic[1], the two battery connectors are just directly connected to each other in parallel (across VBAT and GND).
This seems really sketchy. If you plug in two batteries that are not at the same state-of-charge, then you're going to get a very large current flowing from the higher-voltage battery to the lower-voltage one, probably significantly exceeding the batteries' rated current limits. At best this wastes a lot of power and generates a lot of heat, and at worst it could be a fire hazard.
[1]: https://github.com/ZitaoTech/Hackberry-Pi_Zero/blob/main/Sch...
I was sketched out by BSI not being connected to anything, but it seems it's a fixed resistance battery size/chemistry ID function, not a temperature sensor. That said, I don't see any over/under temperature protection except for some sort of vague temperature limit in the charge IC (which is not thermally coupled to the battery in any way, so only a general "the device is way too hot"), so hopefully that's in the battery - don't go buying any cheapo clones.
I also don't see any fusing, which is a huge no-no. A polyfuse is a twenty cent (ish) part. Again, an official battery would have an internal BMS circuit and prevent overcurrent events, but people are probably going to go for the almost-cheapest battery on Amazon/Ebay. Not to mention counterfeit problems even if you do try to get an OEM battery.
You can think of it like having two big swimming pools side by side, slowly draining out into a little stream. If the two pools are at the same level and the wall between them disappeared, they're largely going to be fine and keep on going.
Now imagine one pool is nearly empty and the other is full. As soon as you disappear that wall in the middle, there's gonna be a very powerful wave as the water from the high pool rushes in to fill the empty pool.
On the other hand, I'll gripe about that "schematic" being not actually a schematic but just loose parts with labeled pins.
To do what you describe, you would need additional components to "switch" one battery at a time into the power path. (This can be done with a single transistor if you're only worried about current flowing in one direction, but I believe it's trickier if you want to support both charging and discharging in the same circuit.)
> Replace your battery in 10 seconds without killing the power!
as a suggestion that you'd have four batteries total, and you'd have two that're fully charged, and you'd replace one battery, and within seconds you'd replace the other. Or at least that's how I'd do it.
I've recently read up about power management and battery charging, and want to make a charge controller than can connect two separate banks. I wonder how hard it'd be to change the IP5306 in the Hackberry Pi Zero to handle the two batteries separately.
"Do things exactly right, quickly, or the device bursts into flames*" is not acceptable electronics design, even for something you intend to use yourself.
* do you really want to trust a generic battery's built-in protection IC?
They don't realize how much current can flow if they slam it to "BOTH" when two batteries with very different voltages are connected.
The problem shows up when you try to "hot-swap" just one of the batteries and replace it with one at a different state of charge, as the README claims you can do.
I've added myself to the waitlist already.
And no that doesn’t need its own computer but it might be nice to have one to be able to hook it up to the network and download and transfer files to the broken machine or be able to download and quickly boot off a rescue image or some such.
These are rare enough problems that I don’t actually bother building a device like that but every time they do happen I wish I did.
Long ago I bought a mini keyboard + mouse combo for input; the custom wireless USB dongle edition I have (strongly preferred over Bluetooth when troubleshooting) is no longer for sale. https://amzn.com/dp/B00I5SW8MC
iPad + $40 RISC-V piKVM-alike [3] is another option.
[1] https://redpark.com/usb-c-serial-cable
[2] https://www.sjoerdlangkemper.nl/2022/11/16/running-etherkey-on-arduino-leonardo/
[3] https://sipeed.com/nanokvmYes, I'm dreaming too.
Beepy is a similar project that uses a RasPi Zero, and their approach is to cut power to the RasPi entirely with a management MCU. On my Beepy, I switched to a Radxa Zero instead and ported over any relevant kernel modules and device tree overlays, because it has an Amlogic SoC that actually supports suspend.
With that Sharp memory LCD and proper suspend that's potentially a gamechanger for the beepy. Any direction you can point me in appreciated.
Feel free to ask in the Discord if you have any questions.
Might be something to look into for design inspiration.
It was so refreshing to have a mobile that acted as a regular Linux machine. You could copy files from your other computers normally just using scp.
Or tweak the GSM radio, as you would do with any other device, just using ifconfig.
It was truly a great experience being able to use your standard Linux tools as first-class citizens on your mobile devices.
https://blog.beeper.com/2023/05/16/beeper-x-sqmfi-beepberry/
I remember this being a cool feature of those GPD Pocket computers. It would be cool to hook something up to the USB and send keystrokes from the steam deck (not necessarily from the touchscreen keyboard, but by scripts).
Would you clarify your categorization?
I personally consider 'portable computer' to be any computer with an internal battery (including laptops etc). I don't find the Steam Deck especially versatile in that category.
A separate/sub-category for me would be 'pocketable computers' (like this Hackberry-Pi_Zero, the GPD Win mini etc) for which the Steam Deck would be unusually versatile—albeit the Steam Deck does NOT fit in any of my pants or jacket pockets.
If not, this might be a good second option for hacking together a chat device for LLMs with notes
I had been thinking about using https://www.lilygo.cc/products/t-deck as a base - but prefer using Linux to microcontrollers
Terminal and ssh will suffice in many cases. People a lot of time used only terminal and live.
The case it a bit too big, there are still battery issues, and of course a 5G card + microphone + loudspeaker need to be added.
But perhaps the day will come that I can roll that wheel to view my emails again, use that excellent small keyboard to reply without having to touch glass.
Punkt showed off a device that had me hopeful for awhile but it doesn’t look like they are releasing it.
The readme is unclear on this subject, they advertise "original keyboard".
It’s an original new old stock BlackBerry keyboard, packaged in a good 3d printed case with Bluetooth, USB and battery charger.
I just built a portable enclosure with a charge controller, USB hub, ethernet and four 18650 batteries. While The Hackberry Pi Zero would've been a lot easier (assuming I'd've just bought one instead of making it myself), the only downside is the battery life. My application is for having a server that travels with me and is on 100% of the time, sometimes running on battery for hours at a time.
This, though, is so much smaller... It's definitely something to consider when they're shipping.
Edit: just read, "Main Processor: Only compaticable with Raspberry pi zero 2w." I wonder why it's not compatible with the original Zero. Is it just that the drivers and preinstalled OS are 64 bit? Even though the 2W is more performant per watt, it still takes more absolute power. Hmmm.
You probably have your reasons but I wonder why anyone would need that
I want a portable server because I want my data to be in my physical possession. Also, I enjoy telling people I'm already doing the thing that they're telling me can't be done.
I'll write it up some time. Perhaps you'll see it here on ycombinator.
One of those super-wide small screens, 1920x720 or thereabouts, with the screen split into 2 terminals. Since I'm wishing, I'd also like that screen to have a 300 to 600ppi e-ink screen built in to a layer, so that when the colour screen is off, the e-ink is visible.
A PC, x86_64 or arm64, built into the screen, with lots of ports, IO, compatible with Pi hats/shields. For extra coolness, a pluggable system like Framework so if someone wants a real RS232 port, they can get one. With USB-C power so I can use any powerbank or other compatible power supply.
A Keychron lightweight Alice-style keyboard, folding a bonus, QMK mandatory, standard bluetooth and/or USB.
[The most useful networking tool I own - AliExpress "CCTV Tester" that does a lot more than test CCTV] Cameron Gray https://www.youtube.com/watch?v=DZQSkFl4yIM
OK, having it be able to function as an emergency USB keyboard is pretty cool, though I think I'd prefer emulation of a USB device so I could run a sequence of commands, inject usernames and passwords for logins, etc.
But a calm, keyboard oriented device just seems great.
There was a team trying to bring it back to life (neo900)
I want the retro feel of mini laptops back when GUIs were only on $20k UNIX workstations.
https://www.lilygo.cc/products/t-deck
Runs meshtastic:
The new UI is being developed right now…
It is a shame, though, to use an RPi and not exploit the GPIO pins a little more. Maybe add a slot on the side to fit some probes or something?
I guess the Pi is all digital anyway so maybe the pins are not as interesting…
512MB nowadays is only practical if you don't use a GUI.
I know how hard it is to do these right and I’m impressed.
Know any surplus stores that carry BB keyboards?
Also battery life would probably sink.
Fairberry has a PCB design for adding Q10 keyboard to any mobile phone with a USB port, https://github.com/Dakkaron/Fairberry
I'd almost be tempted to try to put one together myself, but it's not something I'd find particularly easy and there's other stuff I'd rather spend time on. But might be tempted...
But I have a sneaking suspicion it won't be a big enough quantity to satisfy even the people who've seen this HN submission so may well come down to what time of day / how quickly I see the email
More HackPi Q10 will be restock within 5 days.
More HackPi Q20 will be restock in 2 weeks.The devterm looks like it could be a good device too as you could have pico-8 running on one side with code editor taking up the rest of the screen. https://www.youtube.com/watch?v=5XC5lC9nGWM
Surely, somewhere out there, someone has a small fleet of these cyberdecks, connected with tunnels, doing nicely secure communication ..
We need a better voice to text. One that tunes into its user's voice perfectly without getting distracted. And that you can subvocalize at.
An optimized spoken language for talking to phones too. Something harsh, insectile and dystopian.