Building A Portable Pi

For a long time I’d thought about creating a portable Pi but wasn’t really certain where to begin, so for a long time it remained just an idea rolling around in my head. After building the 600Pi I developed a greater understanding of what was involved fitting a Raspberry Pi inside a custom enclosure, such as extending the USB, HDMI and Ethernet from the tiny Pi and how to power the motherboard directly, bypassing the traditional on board USB port. The 600Pi really opened my eyes and taught me a great deal, not just about wiring, but also about hacking the Pi’s various features. A month or so after finishing that project a friend gifted me a box full of random bits, because if there’s one thing friends know about me, it’s that I love boxes filled with parts. Inside was an assortment of USB cables, fans and a RPI2 B fitted in a custom acrylic case. What caught my attention about the Pi specifically was the 3.5″ LCD panel that was attached to it, as soon I saw the screen the cogs in my head begun to whirr. Well suited for a portable pi project, it was just a matter of me drafting up a design.
A few weeks after receiving my box of goodies I was clearing out a bunch of old stuff from under the bed when I found an old project box lurking under the mattress. A left over from when I was designing my Nomad desktop system, it was just the right size for a portable retro computer, not to mention it already looked kind of old. Originally there had been two but I’d hacked one up for the Nomad, only to find it had very little air flow and caused the mini ITX board to overheat. However, unlike the larger mini ITX board, the Pi not only had a smaller foot print but would never reach the operating temperatures of an Intel Duo processor.  At first I wasn’t certain the LCD panel would fit in the front of the case, but pairing the two together proved it would be a snug fit.

Admittedly, building a portable Pi isn’t anything new, people have been putting them inside all manner of things ranging from teddy bears, tea pots, remote control drones and even coat pockets! You can find Pi powered laptops, C64s, Spectrums and even 3D printed Gameboys like the Pi-GIRRL, however my goal was to build a portable computer with a distinctive 80s retro feel, bet you didn’t see that coming did ya! Using a case originally intended for my Nomad desktop, I decided to call my new portable the ‘Nomad SX/Pi’ in homage to my earlier project and also the Commodore 64SX portable computer, a machine I was drawing much inspiration from.

Design

It’s probably no surprise the SX64, Keypro, Osborne and even the TRS80 M100 inspired the design of my project. All are note worthy machines, successful back in their day with a dedicated group of followers even now. Their appearance resonates a specific time in computer history and it was this aesthetic styling that I wanted the Nomad SX to imitate. Measuring 257 x 190 x 85mm the case had ample space for the Raspberry Pi, however the 3.5″ LCD was another matter. It was almost as tall as the case with only 10mm clearance between the top and bottom lid. As I had done with the 600Pi before, I extended the Pi’s ports to the front and rear panels of the case. Included in the rear panel was:

  • 1 x USB
  • 1 x RS232
  • 1 x Ethernet Port (Rj45)

    Front panel with USB and audio

  • 1 x MiniUSB (Power Input)

For the front I extended the Pi’s audio jack and another of the USB ports along with the Pi’s power and activity lights. Having only recently upgraded the 600Pi with a new Pi3, it meant I had spare Pi2 board with the on board LEDs already modded for extending to the front panel. The reason I didn’t extend all the USB ports was because I needed two of them for Bluetooth and Wifi.

After making a couple of rough sketches I sat down, using Inkscape to draw up the vectors I would need to cut the front and rear panels out of acrylic. Previously I’d used an old version of Adobe illustrator, but a couple of my friends kept insisting I gave Inkscape another shot, even though I’d struggled with it the first time round. My initial impression of Inkscape was that it was powerful but far less intuitive then Illustrator,, but it does have one thing working in its favour. Unlike Illustrator its an open source freeware application, meaning it doesn’t cost you a penny to use.

Better view of the rear panel

Installing it on the Nomad, I spent the evening drawing the panels using the sketches I’d made earlier. After a some what slow start, I actually found Inkscape to be pretty straight forward and not as complicated as first thought. In fact once your in the Inkscape zone it’s actually a pretty powerful application. Available for Linux, Mac OS and Windows, I highly recommend checking it out and did I mention its available for the Raspberry Pi?

Input / Output

One part of the case that was causing me a headache was the keyboard, originally I’d wondered if I couldn’t buy a small keyboard and hinge it to the front of the case similar to the Keypro or attach it with Velcro. However that meant finding a keyboard with the exact same dimensions as the front panel which was highly unlikely. Unlike large manufacturers that can fabricate custom parts, I was limited to finding off the shelf parts to get the job done. After a lot of searching on eBay, I found a wireless keyboard and waited patiently for it to arrive from China. Almost as soon as I unboxed, I realised it was rubbish,

3.5″ of retro goodness

surprise, surprise. The touch sensitive panel was smaller then I’d expected and pretty useless for typing anything. That is unless you wanted to finger type everything, which as I found resulted in almost inebriated sentences of typo ridden nonsense. So it was back to the drawing board and searching once more online for a suitable keyboard, a search that had thus far been less than successful. It turned out I hadn’t needed to worry as only a couple of days after my disappointing eBay purchase, my prayers were answered. While picking the other half up from work, I was telling her about the problems I’d been having when suddenly she revealed her work stocked several bluetooth keyboards on their online shop. A quick trip across

2.4Ghz wireless and sadly disappointing

the warehouse floor and I was staring face to face with an ultra slim bluetooth keyboard and not just that, it was narrow! Talk about irony, I’d spent the best part of a month looking for one under 250mm wide and all the while Pimoroni had exactly what I’d wanted on their website and it was 240mm wide, 10mm shorter then the case I was using.
With the issue of the keyboard finally behind me I was able to redesign the front and rear panels to accommodate the new BT keyboard. Originally I’d planned for the little touch panel keyboard to slide inside a slot in the front, but as that wasn’t happening now, I had to find room to accommodate the larger 240mm x 90x 14.5mm keyboard. Barely 10mm narrower then the case, I had to come up with a smart way of stowing it away. Strapping it to the outside would undoubtedly expose it to unwanted knocks which would likely wear it out in no time at all. Don’t ask where the idea came from but scribbling on a piece of paper I found myself staring at a sketch of the rear panel with a narrow slot for inserting the keyboard inside. Refining the design further resulted with a shelf inside the portable for the keyboard to rest on when it wasn’t in use, I also designed a blanking plate to screwed in place over the slot to keep the keyboard from sliding out while the computer was being transported. While it wasn’t like anything I’d seen on the Z80 portables I’d been using for reference, it certainly worked and solved the problem of where to put the keyboard.

Rear panel went through several revisions before it was right

As there was no need for a slot in the front panel I redesigned it, turning it in to a sliding door and IO plate for the audio jack and USB port. Taking advantage of the reclaimed space I also included a badge to sit above the IO panel which read “Nomad Pi/SX – Portable Micro Computer”. It seemed fitting given the size of the Raspberry Pi computer hiding inside the case.

Bluetooth Woes

Setting up an Ultra Slim keyboard on the RPi wasn’t as smooth sailing as I’d been expecting and required some work before it was up and running properly. I also encountered an annoying problem where the top row of F keys weren’t recognised by Linux, even asking the guys at Pimoroni and on the RPi forum yielded no solution. Two months after finishing the portable Pi I was at a friends sampling a pint of homebrew beer when the answer came to me. I don’t completely recall what led to the discovery (how strong was that beer?), but long story short Linux was mistaking the ultra slim keyboard for a BT Apple keyboard. It turns out these are known for having issues with Linux and there’s even a wiki page covering it, see this link for details.

LCD Screen

Adafruit Powerboost 1000C, a fantastic little PCB

For the Pi’s composite video jack I used a 3.5mm jack cable, splitting the left, right and video lines. I hooked the video feed up to the LCD panel and the audio channels to the audio socket attached to the front panel. At some point I plan on installing internal sound but that will be a work in progress. When I discovered the PI / LCD combo, I originally wrote down the wiring so that I’d know how to connect it back up. Like any scrap of paper it inevitably went missing and not knowing the model of the screen or where my friend had bought it, I was left in a bit of a pickle. How was I ever going to figure out the wiring? Luckily for me I’m on the Sheffield Hackerspace mailing list and after posting up a request for help, I soon had a link providing me with all the info I needed to connect up my tiny screen. Words honestly can’t do justice for how grateful I was when the tiny LCD lit up for the first time, so a big thank you to the guys at the Sheffield Hackerspace.

Because I was planning primarily to use the terminal and not x.org to operate the Pi, I found the text on a 3.5″ screen a little difficult to read. Online I found several guides showing ways to increase the text size within the Linux console, and I also read up on altering the screen resolution which was running in its default res of 1080p (I guess). Either way it was causing the 3.5″ screen to flicker at a headache inducing rate. Fortunately the config.txt is pretty flexible and allows you to tailor a lot of the Pi’s settings to suit your needs, which is great for anyone trying to use a 3.5″ screen with their Pi via composite out.

Tackling Small Screens

Having only ever hooked a Raspberry Pi up to a VGA monitor, I’d little experience configuring the config.txt file to display on a small screen. Especially one using composite output instead of HDMI. Fortunately there’s plenty of information available online to walk you through setting up the config file and a bit of trial and error I was able to get it working. By setting the screen to 480×320, I was able to eliminate almost all of the screen flicker present while the screen was running in high resolution. Additonally making it much easier to read text, as even in 800×600 it was incredibly small. Though lowering the resolution made the text more legible it still wasn’t suitable for using over an extended period. This led me to looking at changing the Terminal itself and how I could configure it to display differently on the Pi Portable. Fortunately you can alter the Terminal using the following command

"sudo dpkg-recofigure console-setup"

Going through the prompts I set the terminal to use the ‘TerminusBold’ font at a size of 11×22 as this was easy to read and didn’t take up to much room on the screen. It took me a while to figure all this out and I went through several computations of the various fonts and sizes before I found the right one. While doing a little research for this article I discovered one of the machines I’d used for inspiration has a larger screen than I’d first assumed. The Osborne-1 is often cited as the first portable personal computer and it along with the SX64 were machines I used as examples while designing the Nomad SX. As it turns out the 1981 Osborne-1 came with a 5″ screen capable of a mind blowing 128×32 character display. Which is impressive compared to the 11×22 display on the Nomad, if I ever make another portable I’ll be sure to make the screen bigger!

Not A Leg To Stand On

After getting the machine together I realised the viewing angle wasn’t exactly ideal. In fact to read the screen I had to prop a book under the case. I’d not really envisioned using a stand like the SX64, but as it transpired I actually really needed one. If I’d stopped to think back about all those old Z80 machines, a large number of them did come with a kickstand of some sort. Designing a set of legs I got them laser cut from acrylic and fitted to the sides of the case. I used nylon lock nuts so that I could tighten the screw enough so the legs were stiff to move, but with the advantage that lock nuts wouldn’t work themselves loose. The downside to using acrylic is that under certain circumstances it can be a fragile material and exposed to stress will sometimes shatter or crack. As the legs would be in regular use, I wasn’t certain how long the acrylic would last. With that knowledge ever present in my mind, I spent a lot of time trying to think of an alternate solution. Eventually I settled upon 3D printing and fabricating a single piece carry handle, as you can see in the picture the prototype came out pretty good.

Being Portable Means Being Portable

Part of this project was to make a portable micro computer that I could take with me wherever I liked. This ultimately meant using a battery, something I’d never done with a Pi before. So once I had the system working and all of the internal wiring finished, I began looking at batteries and also charging circuits. Obviously because of the screen, bluetooth & wifi dongles, I would need a pretty substantial battery to power everything. It was around this time that Pimoroni began stocking batteries via their online store. I also noticed they stocked the Adafruit Powerboost 1000C, a small 5v 1Amp board that doubled as a battery charger. Choosing one of their 4400mAh batteries and the power boost, I set about modifying the internal wiring of the Pi Portable. Instead of the power going directly to the Pi it would have to go via the Powerboost first, so that the internal battery could be charged.
I’ve seldom bought anything from Adafruit aside from perhaps a micro usb socket but I have to say the Powerboost is a fantastic bit of kit and really does credit to Adafruit. Not only was it straight forward and simple to wire up but I found the additional

A sneak peak inside, yes its crammed.

power switch an especially nice feature, one that I hadn’t been aware of at the time of purchasing. It was certainly a lot better than pulling the plug, as is the normal way to turn off your Pi after shutting it down. As the back panel was in need of revision due to some stress cracks showing, I added an additional hole for a switch, which complimented the rear panel really well, giving it a very professional look. Combined with all the accessories, the Pi portable draws approximately 740Mah, which means I should get nearly 5 hours out of the 4400 battery. I’ve yet to actually bench test the Pi portable to find out if those figures are anywhere near accurate, but even if the system can manage 2 hours, I will be happy and consider the upgrade a success.

Closing Thoughts

While it might not be as sleek or as compact as many other portable Raspberry Pi builds. I’ve taken the Nomad Pi/sx to several retro events and had nothing but positive feedback. Many remember using machines like the SX64 and Osborne back in the day and instantly latch on to the similarities. Loading up Dizzy via the C64 emulator never fails to generate a smile. But if I’m honest, I always end up playing Outrun or Stuntcar racer!
This has been a funny old build but one I’ll definitely remember if not for the fact that I do use the computer on and off when I need a distraction free typing environment.


Raspberry Pi Winamp

winamp

Ah Linux, how we do love you, but why oh why are we forsaken to never enjoy a media player such as Winamp! I mean Parole is good, VLC isn’t bad either..But still, it isn’t Winamp is it? If your like me, then the Llama kicking audio player will be one of your staple apps. Its been on every one of my Windows machines for the past 12-13 years. So imagine my disappointment when I started using Linux 4 years ago and didn’t really find anything remotely like it. Fast forward to present day, last Monday to be precise and I’d got my newly built Amiga 600PI running pretty well, the only thing missing was a kickass mp3 player. After doing a search online, I found plenty of people in the same boat, they liked Linux, but they missed Winamp. After doing a little more digging  I learned about XMMS2 and the interesting things people had been doing to make it look like Winamp. Rolling up my sleeves, I gave it a go and while it wasn’t totally straight forward on the Raspberry PI, the results were still pretty successful, so read on.

The first thing you need to do, is install XMMS2 and Promoe client. I did this via the synaptic package manager. Which you can download via this terminal command.

Sudo apt-get install synaptic

Screenshot from 2015-11-19 13:17:19

When you have it installed, open it up and find these files. XMMS2 Promoe Once you have those two files installed, you will find Promoe is now listed in the Sound & Video section of your start menu. Run Promoe at least once, simply to test it works and also to allow XMMS2 to initialize itself. When your done, close the program and we’ll move on to the next step.

Audacious Classic Winamp skin, kicks the Llama’s ass!

Luckily the skins for Audacious seem to work on XMMS2 or perhaps thats the other way around, XMMS skins work with Audacious. Eitherway we need a classic Winamp skin to proceed, so go online and download the classic skin here.

Winamp+Classic+skin+for+Audacious

You should now have a file called “135799-winamp_classic.wsz“, make a new folder and call it ‘Winamp’, extract the archive inside it. See pic Right now here is the part where I hit trouble. According to everything I read online, Promoe stores its skins in the following location.

“/home/pi/.config/xmms2/clients/promoe/skins”

At least it would, if the location existed, which is didn’t on my system. When I navigated to the xmms2 folder, I discovered the ‘clients’ folder wasn’t there.

Here’s a handy tip if your trying to find a file or folder in on your Raspberry PI
find / -name filename 2>/dev/null
 
Swap out ‘filename’ for the name of what your looking for, press enter and wait. Your PI will now go off searching the entire SD card in search of your file. I used this to search for the missing ‘clients’ folder.

Even if the folder structure doesn’t exist, Promoe was still instructed to look in that location. So the best thing to do is make the directories ourselves, as Promoe will then find any skins we want to install. Because the xmms2 folder is a root folder, we’ll need root access to make alterations. Open the terminal and type

sudo nautilus

A new window will open up. You’re now navigating the file system with super user access, so be mindful young padwan. As one wrong keystroke or click here and you could break the entire operating system. And trust me, you really don’t want that! From the top menu, click ‘View’ and make sure “Show hidden files” is enabled. Now on the left panel, click on “File system”. Find the icon named ‘Home’, open it and then open the folder called ‘pi’. Next find a folder named ‘.config’, it will only be visible if you have ‘Show hidden files’ selected. Open the folder and scroll down until you find ‘xmms2’. Open the folder and from the top menu, click ‘File/Create New Folder’, name the folder ‘client’, making sure to keep it lowercase.
Open the ‘client’ folder and create another folder, this time name it ‘promoe’,

Should look like this

Should look like this

again all lowercase. Still following me? good, because we are almost done. Finally within ‘promoe’, make one last directory and name is ‘skins’. All going to plan, you will now have the follow directory structure;

“/home/pi/.config/xmms2/clients/promoe/skins”

 

But wait, we aren’t finished yet, we still need a skin to put inside the skins folder. If you downloaded the one I mentioned earlier, you need to copy the ‘Winamp’ folder in to the skins directory. The simplest way to do this is a drag and drop. First open the ‘skins’ folder you created, then from the start bar, open a new file manager window. Locate your ‘Winamp’ folder and drag it over to the open ‘skins’ folder. Now let us see if it all worked, fire up Promoe, by default it uses the Almond-blue theme. Click on the little blue box in the top left of the interface, from the drop down menu, select ‘Theme settings’. You should now see the Winamp skin listed, click it and voila! Winamp Classic on your Raspberry PI!

Screenshot from 2015-11-19 12:59:34

You can now close all the other windows, especially the one displaying the ‘skins’ folder. Once closed, it will terminate your root access and once more protect your system from any accidental clicks. Until next time, keep on geeking!


Pimoroni Pihub Review

pihub_2 copy

PiHub By Pimoroni

 As some of you know, I dabble on an off with the Raspberry Pi. As a casual user, I use my pi mostly for playing with linux and the odd gaming session. The Pi is a fun little computer, so long as you don’t expect to much from
it. As an indie games platform it offers a lot of fun, so much that I have even felt myself being drawn to writing a program on the tiny computer.

Anyone who has used a raspberry pi for any length of time, will know that cables can soon start to mount up. It’s amazing that such a tiny computer can take up so much room. The RPi can work fine as a stand alone computer, but start adding a wifi dongle, keyboard, mouse, USB memory stick, card reader and suddenly you’ve run out of USB ports. There are solutions to get around the RPi’s two usb ports, but none of them are simple or straight forward as buying a powered USB hub. First and foremost if you buy a hub for your RPI, you have to get one that comes with its own power supply.

On early models of the RPi, the USB ports were fitted with polyfuses designed to protect the tiny computer from devices that might try and draw too much power, such as external hard drives or web cams. Later models did away with the two fuses and now the RPi has just one fuse. While the latest design has improved matters, you are still stuck with just the two ports which is where a power hub like the Pihub comes in, alleviating your power woes and freeing you from two port hell. The Pihub is the creation of Pimoroni, the UK company that also brought us the Picade. Their website offers supplies to a wide audience of tinkerers, modders and electronic hobbyists. One of their recent offerings to the RPi community was the Pihub, aptly named as the housing of the Pihub is in the shape of the Raspberry Pi emblem. Adorned with green leaves and red berry colours, as hubs go it is by far the cutest I’ve seen. The case is but one cool feature of this little device, and the hardware inside is pretty impressive as well. When buying your Pihub, you have the option to opt-out of  buying it with the accompanying power supply. While this might seem like a good way to save money, I would recommend spending the extra money for the PSU as it is well worth the money. Rated at 5.2 volts and 3mA/h, it is more than capable of powering the RPi along with anything else you might want to throw at it. Struggling with external CDROM drives and USB hard drive are a thing of the past. pihub_4
Unimpeded by polyfuses like the RPi, the Pihub offers the full USB 2.0 package, with a multi TT (transaction Translator) chip for bringing USB 1.1 devices in line with the high bus speeds of USB 2.0. Some devices use only
one TT chip, sharing a single 12mb/s data channel amongst several USB ports, which can significantly impede your performance and lead to a bottle neck effect, unlike the Pihub which has been designed to provide high performance. Designed with 4x USB ports, one of which is specifically engineered to power your Raspberry Pi
computer. Providing a dedicated 1.1 Amp supply, it means no longer needing two separate power supplies, you can run everything from just the one psu. For me this is a massive selling point because I found the increasing number of bits i needed for my Pi really annoying. My desk has been turned from crazy cable jungle to almost down right respectable.   While yes, powering the RPi from the Pihub does mean your taking up one of the ports. You’re still left with three full USB 2.0 standard ports as well as the spare port on your RPi. Overall I think the trade-off it worth it.
Speaking with Paul Beech from Pimoroni, he informed me the Pihub had specifically been designed with high quality chips to guarantee 100% compatibility with the RPi. This is no doubt due to the number of cheap hubs on the market, that are less then RPi friendly. Populated-panelsIn an odd turn of events, I actually observed how compatible the Pihub really was in general. After plugging my wifi dongle and mouse in to the Pihub, I connected it to a Windows XP machine. On booting, XP didn’t even ask for drivers, instead logged me straight on to the local area network through the wireless adaptor. I’ve seen few hubs work this seamlessly. High praise has to go to the chaps at Pimoroni. In conclusion, the Pihub is well worth the £20 if you’re on the market for a decent usb hub for your RPi or PC in general. 10% of profits are given back to the Raspberry Pi Foundation, who use the money to help educate future generations of geeks.

Till next time, keep on geeking!

The Pihub can be found via the Pimoroni store at
http://www.pimoroni.co.uk