Huge Functionality, Small Package: A Custom Tablet, Raspberry Style

As the adage goes, “if you want something done right, do it yourself.” Desirous of a tablet but preferring to eschew consumer models, [Stefan Vorkoetter] constructed his own compact and lightweight Raspberry Pi tablet, covering several extra miles in the process.

The tablet makes use of a Raspberry Pi 3 and the official touchscreen, with the final product marginally larger than the screen itself. Designed with a ‘slimmer the better’ profile in mind, [Vorkoetter] had to modify several components to fit this precept; most obvious of these are the removal of the Pi’s GPIO headers, USB, and Ethernet ports, and removing the USB power out port from the touchscreen controller board so the two could be mounted side-by-side.

An Adafruit PowerBoost 1000C handles charging the 6200 mAh battery — meaning up to six hours(!) of YouTube videos — via a micro USB, but only after [Vorkoetter] attached a pair of home-made heatsinks due to negligible air flow within the case. A modified USB audio adapter boosts the Pi’s audio capabilities, enabling the use of headphones, a mic, and a built-in speaker which is attached to the tablet’s back cover.

A number of hardware additions include an external clock chip — the DS3231, a USB port for peripherals, a trio of recycled buttons to access some oft-used functions — such as bringing the keyboard to the fore, and a power switch connected to a custom circuit board that monitors battery voltage and acts as a shutdown controller.

Paint and final assembly completed, [Vorkoetter] added a few features to Rasbian Jessie to make it a functional tablet — notably xvkbd touchscreen keyboard software, twofing to make the touchscreen behave as a conventional tablet, and a custom tablet daemon which [Vorkoetter] wrote themselves.

From there, there’s little left to do but enjoy all of this in a 16mm thick package — if you don’t feel like going the other way and turning a tablet into a laptop.

35 thoughts on “Huge Functionality, Small Package: A Custom Tablet, Raspberry Style

    1. I’m interested in something between this project and the Pinebook. Pinebook res at tablet size. RasPi 3’s built-in Ethernet. RasPi’s GPIO, all at Pinebook price or less. The application I’m thinking of is a per-room home-automation terminal in place of the traditional light switch panel.

  1. So very well constructed and smaller than my initial plan of a Pi tablet PC. Some questionable methods of custom circuitry though neatly constructed, though it would be more “Not A Hack” (TM) without them circuits.
    .
    .

    An upgrade would to have a mosfet controlled pseudo-ACPI power hack so the switch can be replaced with a button for both power-up and shutdown (add a 555 for long-press force cut-off).
    for example:
    Archos seemed to use a bootstrap-and-GPIO-locked power-on mechanism in almost all their old player/tablet PCs. It may not be instant-on but it stopped accidental boot-ups. The mechanism was controlled by the bootloader kernel if I remember rightly, the bootloader would keep the player running whilst strapping the boot kernel(s) to complete the ROM stage of power-up.
    Inaccuracies (if any) are likely because: It has been a while since I modded one… 600MHz is beatable by the first RPi so they’re underpowered machines…. with SATA HDDs though but OMAP-3x with binary-blob GPU, DSP, etc.. So are not of any interest these days. (Similar HW to the N900)

    Instead I’m already working on recycling that x86 snap-top of mine now it has served its’ purpose shortly after the hinges snapped.

  2. A Raspberry Pi Foundation “RPi Laptop” is loooong overdue in my opinion. It’s clear from several examples on the market today for a RPi Laptop that it’s fairly easy to do. But the problem with the current RPi Laptops out there are 1. Too expensive, and/or 2. Too hard to buy. I’m not blaming these existing RPi Laptop projects for anything – actually they’re quite good from a design stand-point. The problem is Hacker/Maker RPi Laptop solutions do have the economy of scale that the RPi Foundation can bring to this. The RPi Foundation developing a laptop would be similar to something like the One Laptop per Child (OLPC) project(s), which are OK, but limited to essentially institutional volume purchases. A RPi Laptop solution would be (eventually) accessible to almost anyone, globally, unlike the past OLPC efforts. There’s one additional KEY factor that solves the ongoing HUGE problem with the Raspberry Pi – it doesn’t have VGA output. VGA output is still important in developing countries. Where do you think your old VGA monitors go anyway? If they work or can be fixed, they go right back into service in the third-world – I know, I live in a (rapidly) developing country (Indonesia). RPi Foundation really dropped the ball when it came to VGA IMO. A RPi Laptop works-around the VGA problem because it has a built in display. But that doesn’t excuse the RPi Foundation from including basic VGA output in the first place. For every RPi Laptop taken up, there’s a good chance a readily working VGA monitor will go into a very bad disposal/reclamation chain. Bad for the economy, bad for the Planet.

    1. Correction in my post:

      “The problem is Hacker/Maker RPi Laptop solutions do have the economy of scale that the RPi Foundation can bring to this.”

      To:

      “The problem is Hacker/Maker RPi Laptop solutions do NOT have the economy of scale that the RPi Foundation can bring to this.”

      I think the HaD comment system did this to me. But I’m not positive. I’ll watch my posts going forward to see what’s up.

      1. There are so many other boards beyond the Raspberry Pi, and nearly all of them have a much favorable performance/price ratio, even compared to the almost unobtanium RPi Zero. However, the point isn’t just making a tablet with known hardware as cheap as possible but making a point to the manufacturers that we badly need a tablet platform with open drivers so that we can install a true Linux OS on it, thus getting full control of what it does.

  3. Here’s a semi related question…

    I’m looking at doing a similar thing, but I want to use a mini keyboard with a built-in touchpad. Easy enough until you want one with a USB cable and not bluetooth (I don’t want bluetooth to connect the keyboard in a laptop for power, reliability and security reasons)

    Can anyone point me to a mini wired USB keyboard with a touchpad?
    Or an easy way to convert a bluetooth one to wired USB?

    1. I use a Logitech K400+ BT keyboard with my R Pi USB input via a $10 BT=>USB dongle. The keyboard goes months between AAA battery changes and the BT range seems to be only a few meters line of sight, so reliability and eavesdropping shouldn’t be much of a problem.

      1. Yeah, The additional touchpad from a laptop is my last resort if I can’t find a keyboard with integrated touchpad. I already have a mini USB keyboard, and some old laptop touchpads, but I was hoping there was a nice integrated solution out there somewhere.

    2. Not that “mini” but Perixx makes a “Periboard” line of compact keyboards, one of which might work for you. Their model 515Plus is like a that may fit the bill. Their model 515Plus is like a Logitech K400 but wired.

  4. At this size is it a tablet? It looks like a smartphone.. except of course… no phone. That makes me think PDA might be the word. No, I’m not putting it down by saying that. It’s like what PDAs might have become if cellphones hadn’t taken over that market. I’m thinking several generations into an alternate universe Sharp Zaurus. I loved my Collie! Awesome! Great job!

    I’ve been daydreaming about making something like this for years. I’m not much closer to doing it though. Currently I am at least picking up a little speed at assembling my 3d printer… One day I hope It will print the case.

    Since I very well may never get to building mine want a couple of the ideas I daydream about? One is to include a USB cellular modem. That’s not such an original idea, I’m sure everyone who makes something like this considers it and decides they do or don’t want it. Here’s one I haven’t heard anyone talk about though… think back… 1990s laptops. Anybody remember the XJack? https://en.wikipedia.org/wiki/XJACK How about a Raspi cellphone with XJack for Ethernet?

      1. Nah, the screen on the zero phone is too small.

        SPI is cool. How about a built in Bus Pirate?

        One of my goals if I ever get around to this project is to come up with a way to make my own XJack. Should I fail… maybe I will troll eBay for an old 10bt card.

  5. I’d not worry about it being thick and would have retained the USB and Ethernet ports, the extra space at the other end would mean an even bigger battery capacity. I don’t see what the big deal is with having a thin tablet. I never complained about a book being to fat, I’d even like a tablet that had a cover so that it did look like a book.

  6. Whoa, finally some enclosure which does not looks like utter garbage crap. Really impressive woodworking. On downside, wood isn’t fire resistant at all and if one grabs big 6000 ma LiIon it could be something to consider. Another problem would be the fact Broadcom “power management” just does not exists. So it would do 6 hours of youtube, but when it would come down to standby time, it would be no match to real tablet. Or even allwinner/rockchip SoC boards, where one at least gets more or less working DVFS. After all, downclocking and downvolting idle circuitry saves HUGE amounts of power. Since Pi’s power management is a piece of shame as it does not exists, such tablet would be impractical. I doubt it could even beat deep-sleep (suspend to RAM) of x86 laptops. Tablet could get 2 weeks of idle of 6000 ma battery. Laptop would get these 2 weeks of larger battery. Pi… no way it could last for 2 weeks, unless you’re going to use far larger battery.

  7. I usually pass straight by computer builds, but this is truly exceptional. The size is great, the battery life great, and the philosophy great (having a tablet sized computer that is actually a computer and not some manufacturer-locked-down gadget with proprietary drivers that locks you out of doing anything interesting and bricks itself when “upgraded”…). The writeup is excellent, and if I had the time and gear I’d make one myself.

    My *only* complaint is that there is only one of them, otherwise I’d be ordering today.

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