A Raspberry Pi Handheld Computer You Might Want To Use

Amid the many wonderful form factors being explored by the makers of cyberdecks, there’s one that’s emerged which harks back to an earlier generation of portable computers: the handheld pad with a keyboard. These units are typically around the size of a hardback book, with the upper half being a screen and the lower a keyboard. The latest to come our way is from [Richard Sutherland], and it’s a very tidy pad computer indeed.

Inside the well-designed layered 3D printed case is the frequently-chosen Raspberry Pi 4, along with a PiSugar power supply board and 5,000 mAH battery and a 4.3″ touchscreen display. The keyboard has seen a lot of care and attention, featuring high-quality tactile switches that follow the Miryoku keyboard layout. He says it’s a thumb-typing keyboard, but anyone looking for more can either adapt the design to their liking or simply plug in an external board when faster typing is needed.

We like the pad computer trend as it offers useful computing power in a far more convenient format than a laptop, and we think this is a particularly nice one. It would be nice to see where people take this design, and who knows, we might give one a try for writing some Hackaday articles. If you’d like to see more pad computer goodness, we recently showed you one built in the shell of a classic Amstrad.

49 thoughts on “A Raspberry Pi Handheld Computer You Might Want To Use

        1. My old 286 ran Windows 3.0 on 1MB. GUIs don’t actually need that much memory, with smart (and non-lazy) coding, if you don’t add a ton of pointless bloat. And a quick look at the system requirements reveals that it only _needed_ 384k. Of course, it didn’t do true multitasking. Windows 3.1, which _did_, requires 3MB. The _Pico_ almost has enough ram for Windows 3.0. The Pi Zero, with 0.5GB can _trivially_ run a GUI, if it isn’t horribly bloated and lazily coded.

      1. my pi 4b has 2GB RAM, and has 1674MB free. i even disconnected the monitor but didn’t bother to kill the GUI because it has so much extra RAM. you can definitely — and easily — fit a GUI inside of 512MB. what you can’t fit is a modern browser, or gnome.

      2. The Pi Zero 2W has enough guts to support a graphic UI. The problem is that Pi OS has by default a much too small swapfile of 100 megabytes. That pretty much prevents even opening Chromium given the 512 megs of RAM. Yes, you will have swapping going on, but performance will be tolerable if you use a high write-endurance U3 SD card.

        I increase the swap to 1024 megabytes. Here is how:

        Open a terminal prompt
        sudo bash
        dphys-swapfile swapoff
        nano or vi or your preferred editor /etc/dphys-swapfile
        Change the line
        CONF_SWAPSIZE 100
        CONF_SWAPSIZE 1024
        save the file and exit the editor
        Initialize the new swap with
        dphys-swapfile setup
        exit the elevated privilege bash shell

        Enjoy a much better performing Pi Zero. If you have a small screen and/or monochrome display, you could reduce the amount of RAM allocated to the GPU in the Pi Setup program. No, you certainly aren’t going to mistake it for a 3 GHz Quad core i7 with a $1,000 GPU board, but you can do real work on a computer which uses about 5 Watts of power and fits in a FLIRC case the size of a chewing gum pack.

        I’m scratching my head why the Pi Foundation didn’t increase the RAM size on the latest iteration of the Zero when they beefed up the CPU. It must not have been a supply chain based decision because it takes months to get an order for Zeros to be filled anyway.

        1. I suspect they didn’t bump up the RAM because it adds unnecessary costs to every board for almost no user gain – you want small potent Pi with more memory you get one of the compute modules they already have a great product that fills that role.

          The zero’s have always been that slightly odd middle ground between ‘real’ computer and the ardiunio like microprocessor – and you don’t really need the CPU or RAM to be superb for that…

      3. > The problem with a zero is that it has not enough memory to be really usable with a graphical interface. You are doomed to the command line interface.

        Just assume I’m totally aware about what which Pi can do for me.

    1. If you don’t put a great deal of load on it idling along that battery will last a good long time with a Pi4, its big enough to last a good while with the Pi working flat out (though I suspect it will throttle quite hard in that situation – the cooling used isn’t bad don’t get me wrong, but not sufficient to keep up under prolonged load).

      Putting a zero in the pi4’s place will get you slightly more battery life just idling along, but in use I suspect you’d end up with worse battery life – the zero would end up running flat out and staying there for prolonged periods as it can’t just do everything you might throw at it as easily as its more powerful Pi 2, 3 or 4 siblings with the low ram likely to be a big bottle neck – but your millage will vary hugely depending on what you actually want to do on it…

      As shinsuke says the screen is also likely to be the biggest energy hog. So if you really want an all day terminal computer with a pi you probably want one of those monochrome calculator style LCD or perhaps e-ink screens…

      Though you could just reshape the case a little and stuff in a much much bigger battery – perhaps one of those RC aircraft/multi rotor sized pouch battery – then its just pick how much runtime you want. Which for a Pi4 worst case stress test running is something like 5V at 3A, figure 4A if you have much in the way of accessories connected, but more realistic use case I’d say rounding up to 1A* is about where its going to average out for most desktop users while really using the device…

      *For reference I do often use my Pi4 as a media player, web reference and FreeCAD machine at the same time to get that average around 1A sort of figure – obviously it spikes right up to the redline often in such a situation and with the beefy cooling mine has its got a hefty overclock so runs hotter at that point than a portable ever would, but there is then all the thinking, reading, and procrastination time when its lightly loaded…

      1. i’m getting 500mA typ power consumption for idle pi 4b, or 10 hours of idle time. compared to 250mA typ power consumption for fully loaded pi zero, or 20 hours of full tilt. you can find different numbers out there but it’s within that ballpark. the fully loaded pi zero draws much less than the idle pi 4b.

        you don’t need to make up numbers. you can look it up. if you aren’t designing portable devices then there’s no reason to know the pi is a power hog but if you are then it’s the central factor on your mind.

        1. You can get lower than that with an idle pi 4 SOC, if you care to try, though probably not by much i’d agree, but the zero 1* can go higher than 250, quite a bit higher if you want to push it, and will have to run nearly flat out all the time even if you overclock it hard and it will still be crap for more normal computer use… All swings and roundabouts there but my personal experince says a zero will be fully loaded nearly 100% of the time if you are using it, and cranked up as far as you can take it so its less horrible to use consumes more than the pi4 chips I’ve played with sitting idle (though most of those experiments are compute modules, which does shift things some more).

          The zero family is far easier to reduce the idle current draw draw on for use in those more arduino like embedded like projects, and where it shines in providing more compute horsepower than the little microprocessor boards – its pretty crap and needs cranking up as far as you can take it to be a still pretty much unusable ‘normal’ computer…

          *Also which model of zero – the 2 is better in many ways power wise, as its got enough performance to be plausible in such a role for real world use but also idles higher than the og zero etc – so I was more figuring you would use in this case the zero 2 – something that won’t be so awfully slow you die of old age and drink far too much tea while waiting on it to do the most basic tasks…

          1. no, that’s not how it works. you scroll, the pi 4b will be relatively smooth, 10+fps so you can easily tell whether you’ve scrolled enough. the pi zero will be frustratingly jerky as it scrolls, maybe sometimes you will even have to wait a second before the updated information shows on the screen.

            and then you read it. and both processors are the same level of idle (though different power consumptions) while you read it. the zero isn’t magically pegged at full consumption just because the scrolling itself was so slow. you don’t need cpu to display static content. and most computers spend most of their time idle.

            if you are constantly scrolling, the faster cpu will never reach idle, it will be running full tilt as well, just displaying more intermediate frames than the slower cpu.

          2. With all the GUI pretty factors that exist even on ‘lightweight’ desktops now just moving the mouse is rather hard work on such weak hardware, so you are probably goign to spend twice as long going for your target… But it is not really the displaying of static information but that there is always background processing – especially if as is usually the case that ‘static’ information is being read from a web page!!! As Web pages these days are very very bloated things, at least if you don’t actively work to strip out of the functional JS, changing or even video advert boxes etc that are so common…

          3. Also remember your ‘static’ is never really static even with just the basic desktop display and no user selected actual programs running with any GUI – its updating date/time, polling your feeds, checking for updates, syncing your folders, showing the CPU load, etc – all the basics that actually make a GUI worthwhile over the terminal sometimes… Even those minor little processes add up to meaningful load on such weak systems where the more mighty systems can handle them without any detectable change in clocks and power draw from the lowest they can go…

            Though it is mostly all the background bloat on the webpages you are likely to connect to – even relatively low challenge webpages like some router config page are likely to making a zero work hard…

  1. Why not just use a smartphone? It’s going to offer an experience 1,000,000X better than a Pi Zero. The Pi boards are great for lots of things, but I see so many people using them for stupid things.

    1. Because where’s the fun in that?

      Also, a smartphone is more proprietary, less extensible, and doesn’t have a built-in keyboard. This is *exactly* the kind of project that the Raspberry Pi is meant for.

    2. If all you want is a terminal interface a Pi zero is perfectly capable, and if you want more the Pi4 family are damn impressive in performance, in many ways better than the smartphones as they are powerful AND just a ‘normal’ ARM computer so can actually be used in a way a technically more potent smartphone can’t (easily anyway).

    3. Exactly this 👆

      This contraption is actually upsetting. We have so much hardware and technology in smartphones- yet so little physical computing and custom development, why, rhetorically speaking?

      Android too locked down? Need GPIO breakout? Let’s go.

      Sure, separate embedded hardware ‘can’ make sense for the use case(s) of having something standalone and/or dedicated, but if the expectation is to carry this around- in addition to a far superior “pocket computer” – no thanks.

  2. This is a great article and love the result but honestly Raspberry Pi’s are so expensive these days and hard to find to where this isn’t as viable option. Cool concept though

  3. “This is a great article and love the result but honestly Raspberry Pi’s are so expensive these days and hard to find to where this isn’t as viable option. Cool concept though”

    And to think, these single-board Raspberry Pi kits used to be dirt-cheap. But not anymore, since the COVID pandemic body-slammed nearly every nation on the planet…starting in (and including) China, where most of these (and similar) kits came from.

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