Hacker News new | past | comments | ask | show | jobs | submit login
How I Built a Raspberry Pi Tablet (makezine.com)
185 points by nkvl on Jan 14, 2014 | hide | past | favorite | 36 comments

For those interested in the actual build process and materials rather than just a writeup, here it is from his personal site: http://mkcastor.com/2014/01/02/pipad-build/

A compliment from Bunnie is something to be proud of! The PiPad looks awesome, well done :) I'm working on a palmtop in the vein of an HP 200LX, running RetroBSD on a PIC32 micro controller. So much fun, but gosh hardware hacking is harder than I thought. New found respect for the hardware people!

HP 200LX is so neat, so I'm immediately interested in your project. What sort of keypad and display are you planning to use/make? What about case, a 3D-printed one?

Using PIC32 sounds like a challenge, it would be in the same ballpark than the original 200LX performance wise?

RetroBSD is a port of BSD 2.1 for pic micro controllers, so a lot of the work is done for me! I'll be writing drivers for the lcd and key pad. I'm going to be making the keypad from scratch at this point, but performance wise it's actually pretty damned fast!

This is the board I ordered: http://www.seeedstudio.com/depot/fubarino-sd-p-1265.html

PIC32MX440F256H - 256K Flash, 32K RAM @ 80MHz 32-bit MIPS core

While the RAM is lacking, it should be enough :) the case will likely be vacuum moulded, I've experience doing that when I use to make portable consoles from hacked SoC's, but the prototype will be 3D printed for sure.

Does RetroBSD really work with only 32K of RAM? Their frontpage just mentions: "RetroBSD needs only 128 kbytes of RAM to be up and running user applications."

Oops, I linked the wrong board!

Fubarino SD chipKIT http://fubarino.org/sd/index.html

Little bit better ;)

It's only for prototyping to be honest, I'm likely to end up wiring up my own PCB with the chips myself, to give me more flexibility in shape and speed, but for now this will do to get it started!

Sweet! That sounds like a really nice project, I'd totally love to see it running!

My board just arrived, so I'll be testing things out soon! Either keep an eye on my site in my profile or on the RetroBSD forums :)

Quick grep for cost/price didn't show up anything. Sorry if I missed. How much did it cost? Just out of curiosity, I'm wondering if it's possible to build an extremely cheap but waterproof tough tablet for toddlers to play with. They don't care about performance at all.

Hey, let me know if you do. I am not a toddler (of course), but for my kayak trips I need something decent, cheap and waterproof.

Check out aLOKSAK bags. I've successfully tested my Nexus 7 tablet under the shower with one of these bags. For scientific purposes, of course.

For science, I'd put silica gel crystals in it and take it to the shower before I dunk my tablet :)

You could just use a square of cardboard... why use electronics at all :)

Because it won't tell you if there's humidity inside the bag that could potentially harm your device. Silica gel isn't electronics. It'll change color when it detects moisture.

I don't mean to sound as a luddite, this is an honest question: why would you need a raspberry pi tablet in a kayak trip?

Maybe he needs a cheap display for reviewing photos taken on the trip? Something, he might do some basic editing on? Something durable, not too expensive, that fits his needs.

Just throwing thoughts on a wall, waiting to see, that sticks.

sdoering got most of it right. I also would add backups, it doesn't feel safe keeping all your pictures on cameras sd cards for weeks. Actually, for me it's mostly backups, that's why a dirty cheap rougged tablet would be nice (cheap because I don't do many of these trips).

That's a lot. I was looking at $50-$75 price point. Don't care about screen resolution. It can be resistive touch. One can skip on storage too. But it needs to light up when you touch & make sounds. Most of all, handle all the abuse :)

You were hoping a single hand-crafted unit to be cheaper than majority of massproduced chinese crap?

I put my Raspberry Pi inside an iPod: http://peterburk.tumblr.com/pipod

If you are interested in hardware components these people have decent products http://www.hardkernel.com/main/products/prdt_info.php

Are there any commercially available Linux-based tablets out there that people can recommend?

Nexus 7, replace ROM with any Linux port. That's what I did anyway :)

What's the average battery life like (and which distro)?

Not the OP, but I'm guessing Ubuntu? Especially since Unity is touch friendly and Ubuntu is generally the best Linux distro out there when it comes to drivers etc. Also because Ubuntu are developing a touch version for the N7.

I'm guessing the battery life is probably around 7 hours or so. Again, take this with a grain of salt :)

Ubuntu Touch is currently in a weird state with regard to Nexus 7 support in that the current pre-release build doesn't support the newer, far superior Nexus 7 2013 model (razor), only the older model (grouper), but Canonical also has announced that moving forward grouper support will be killed and only razor will be supported.

Considering it is all in a developer preview state at this point, this isn't a big deal but may be important information for anyone thinking about buying a nexus 7 right now to be used as a native Ubuntu device.

> Ubuntu is generally the best Linux distro out there when it comes to drivers etc

Thank you for this comment. It shows how RMS was correct; when people think "Linux", they should really be thinking about the kernel inside the computer. This is what handles "drivers, etc" that you were talking about. a Linux Distribution (normally referred to as GNU/Linux, because it has a full GNU system alongside the kernel) can have a branding such as Red Hat, Debian, or Ubuntu. A similar situation exists in the BSD landscape as well; FreeBSD and Apple's MacOS share kernels (Darwin was based off FBSD's kernel), but you're really just using a branded version of Berkeley Systems Distribution.

Ubuntu provides a GNU/Linux distribution (though they seem to be anti-GNU overall) with the latest stable kernel they can get away with. Any distribution with a kernel of the same version will have the same hardware compatibility with "drivers, etc".

Unity is not the only touch interface. Plasma Active and Enlightenment both have touch interfaces that make Unity pale in comparison.

Ever used plasma on an touch screen? It's terrible. Getting better, sure, but not good in my opinion. Unity is far more consistent and modern in touch usage, IMO.

After trying Ubuntu Touch on my 2012 Nexus 7, and finding it WAY too unstable for my needs (I averaged maybe 10 minutes of use between hard crashes), I installed Arch on a chroot, accessed via VNC. The specific applications I used are Linux Deploy and bVNC Free. Added an external bluetooth mouse and keyboard (the keyboard being a cheap cover-with-gutter thingie), and presto, a usable desktop Linux in my coat pocket.

It works better than expected (no crashes, slight lag but nothing serious), and I can do 50 wpm on the cheap keyboard (after some extensive remapping), which surprised me (my average speed on a full keyboard is around 100 wpm). I've typed and LaTeXed a few papers on the thing, and just yesterday I built R from source for a biostats class.

Just nitpicking over the website: loading the gif took some time... yeah, 18MB, it was a good occasion to test gfycat: http://gfycat.com/OblongSilentAndeancat it could have been reduced to 6MB.

Related discussion from 2 weeks ago: https://news.ycombinator.com/item?id=6975202

This is a really cool DIY project, but probably not practical. That thing's going to be slow as molasses.

Maybe with the RPi, but not if you use the board from this comment: https://news.ycombinator.com/item?id=7055540

Quad-core 1.7 GHz Exnyos with 2 GB of RAM for $59.

I just found out about this board, but it appears pretty impressive for the price. Has anyone used it?

You can read more here:


It all depends upon the end goal in terms of practicality. It would be too slow for me as well, but it looks like it is fast enough to watch a movie during a commute, or to read a book.

However, totally agreed on the cool factor of the project!

I like the woodgrain bezel. It looks like a device from the movie Her.

I think this is wicked cool. Is the underlying desktop mouse based or optimized for touch?

Applications are open for YC Summer 2021

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact