Saturday, February 15, 2014

Jayme Gisbourne’s Porta-Pi

Last Friday night I spotted a tweet with a picture of a Raspberry Pi running on a screen and mini keyboard concealed within a small hinged enclosure:

I thought it was great! Then the next morning I spotted the very same box while wandering around the Cambridge Raspberry Jam – and was pleased to be able to see it for real – especially impressed when I discovered the maker behind the project was a 14 year old school boy.

Jayme Gisbourne is a very bright and forward thinking fourteen year old. Over to Jayme…

My name is Jayme Gisbourne.
I live in Harlow, Essex.
I attend Stewards Academy.
I am 14 years old.
I am a big STEM enthusiast!
My favourite films are all six Star Wars.
I want a PhD in Physics and Engineering.
I am an extremely big nerd.
My biggest STEM influence is my granddad, a tool maker and builder. He gave me 70% of my tools and 100% of my engineering knowledge. He has taught me everything.
As well as Engineering I have another interest, I am a target shooter. I compete in shooting competitions.
I love Engineering and Science!
I love the Raspberry Pi!

I first got into the Raspberry Pi world by not knowing what I was doing. I wanted to change one of my GCSE options to computer science (I want to be a Physics Engineer so I thought this would help with the engineering side of the job). It was too late to change options as a year had already passed since everyone started the GCSE and they thought I wouldn’t be able to catch up.

In order to prove my self I wanted to start from extra curricular activities, e.g. coding clubs. My mum’s work friend is wedded to David Whale (A STEM ambassador, software engineer and a extreme coder) he managed to get me tickets into the Raspberry Jam convention in May 2013. I entered a competition, it was a quiz about the Raspberry Pi. I have had been picking up information all day about the Pi so I could show the computer science teacher what I had learnt and maybe he would allow me to join the class.

With that information I won the quiz and a Maplin Raspberry Pi starter kit containing everything that I would need to use the Pi. Later that week I was accepted in to the GCSE computer science course and within weeks I caught up with the rest of the class.

During the Raspberry Jam convention I met Sukkin Pang from SK pang Electronics which was also an old friend of my mum’s. He was presenting his Portable Pi and I was intrigued with the engineering side of the design. He used a laser cut base instead of a foldable case like mine. I would recommend that you check out SK Pang Electronics - they have a wide range of stock at reasonable prices (and no, he is not paying me to advertise him!).

Since my introduction to the Raspberry Pi, it has taken my STEM interests so much further. I have been coding games like Space Invaders, a flashing LED game, etc… The Raspberry Pi has opened so many doors for me, I went on school trips to STEM meetings to show off my Pi, met so many STEM ambassadors and Raspberry Pi enthusiasts. The Raspberry Pi has made it easy for me to promote our schools Raspberry Pi club to other schools and Raspberry Pi clubs. The Raspberry Pi has also brought me into the STEM world. Without the Pi I wouldn’t know what I would be doing, the Pi has really improved my life educationally and throughout the STEM world.

My biggest wish is to own and use a 3D printer, but they are way out of my ‘pocket money budget’. I could make so many more Raspberry Pi projects with one!

Parts list:

  • Raspberry Pi
  • SD card loaded with the OS, etc.
  • USB-Mini USB cable
  • 5 volt USB output portable phone charger
  • Car reverse LDC screen
  • Solid core bell wire
  • Mini wireless keyboard
  • A material for the case (acrylic/Perspex, 3D printed PLA Polylactide / polylactic acid, etc.)
  • Adhesive for the material (may not be used depending on the design of the case), e.g. Tensol 12 or 70 for acrylic/Perspex
  • Cyanoacrylate adhesive
  • Two part epoxy resin adhesive
  • Hinges (preferably plastic: nylon or 3d printed)
  • Paint for the hinges to match parts of the ‘Porta-Pi’ (I painted the hinges black to match the keyboard and screen)
  • Hot glue
  • Solder
  • Polyvinyl Chloride tape (PVC/Electrical tape)
  • If you are using acrylic/Perspex you will need Tensol 12 or Tensol 70

Tools/Equipment list:

If you are 3D printing obviously a 3D printer is needed, if you are using acrylic use a laser cutter or hack saw (make sure the hack saw blade has fine teeth, at least 18 teeth per inch).

  • A hand, cordless or cored drill
  • Assorted drill bits (preferably HSS bits for drilling metal is used) the size depends on the size of your wires
  • A soldering iron
  • Wire strippers
  • Pliers
  • Engineer’s square
  • Steel rule
  • Callipers
  • A scribe/scriber
  • A permanent marker pen
  • Set of metal files (single cut files, bastard cut files, second cut file, needle files, etc.)
  • A Dremel
  • A bench vice with soft jaws
  • Dremel cut-off wheel
  • Dremel sanding drum
  • Dremel milling bit

It is advised that you have at least a basic knowledge of circuits and engineering, the wrong connection of wires could break your LCD screen or Pi also acrylic/Perspex is extremely brittle and it scratches easily so be careful.

In the instructions I will show you how to make it out of acrylic/Perspex.

Instructions:

1) First shorten the USB to mini USB cable so the overall length is approximately 3 inches. Solder the wire back together, leave the solder exposed, you will need this in the next step.

2) Get the LCD screen and follow the power cable past the fuse, past the power connector and solder the positive wire to the positive wire on the USB to mini USB power cable do the same with the negative wire to the negative wire on the USB to mini USB power cable:
- negative to negative
- positive to positive

If you have correctly followed the instructions you have now completed the USB to mini USB power cable. Now cover the exposed solder joints with electrical tape, be sure that the negative and positives do not touch!

Now we need to make the LCD screen with a 12 volt input run off a 5 volt input by bypassing the voltage regulator.

3) Remove the back plate from the LCD screen be careful not to damage the circuit board.

Cut the positive wire (near the power connector) leaving some space to strip the wire, connect the now striped positive wire to the second terminal on the first capacitor.
To check it works use he solid core bell wire to connect the composite output (on the Pi) to composite input (on the LCD screen) and then run the Pi itself off the battery using the USB to mini USB power cable that you just made. If it doesn’t work try another terminal (be careful this could harm the LCD screen).

The next steps are really important!

4) BEFORE SOLDERING CHECK THE CIRCUIT IS CORRECT AND THE CURRENT PASSES THROUGH. TO CHECK IT USE A CONTINUITY TESTER TO SEE IF IT PASSES A CURRENT, IF IT DOES – TURN ON THE BATTERY AND CONNECT THE WIRE WE JUST MADE TO THE BATTERY, TOUCH THE POSITIVE WIRE (THE WIRE YOU JUST STRIPED) TO THE TERMINAL THAT PASSED THE CURRENT AND CHECK THE LCD SCREEN WORKS WITH A 5 VOLT INPUT.

IMG_0002

It should look like this picture above.
*Always check that it still works before soldering*

Now you have a portable Raspberry Pi!

5) For the case I transferred the now portable Pi (with out the screen, that’s something different, we will come to that later) on to a piece of paper. I found the most compact configuration and drew a box around it. Do this to all three dimensions.

Use scissors to cut out the box that you have just drew on.

Now you can use this as a template to cut all of the sides.

Each dimension (height, width, length) you will need to cut out two of each except for the bottom panel (length) you will need four of them (we will need the other two later for step 9).

6) If you are using a hacksaw- create square angles with the engineers square mark the acrylic/Perspex with a scribe/scriber, if you want you could rub permanent marker ink into the scribed line so it is easier to see.

7) Now take one of the four bottom panels and using the Dremel cut off wheels, sanding drums and milling bits cut a hole for the mini wireless keyboard to fit in. Once in use the epoxy resin to keep the keyboard in place.

*BEFORE ASSEMBLING ALWAYS FILE THE ACRYLIC/PERSPEX. USE THE DRAW FILING TECHNIQUE FOR THE SIDES OF THE ACRYLIC/PERSPEX!!!*
Now finish the rest of the case for the bottom half containing the battery, power wires, Pi and the keyboard. Allow time for the adhesives to cure, Tensol 12 takes at least 3 days to fully cure but it can be handled within five hours.

9) Now to make the top half follow step 5) you don’t need to make the top and bottom panels because you cut two extra for this step. To cut out the hole for the screen follow step 7). Use the protective 1mm thick plastic screen from the original LCD housing and push it off from the back. Place the screen over the now installed LCD screen in the case.

10) Now assemble the Pi using the correct adhesives.

11) Using paint, paint the hinges to match the case and Pi. Using epoxy resin to stick on the hinges to the case connecting the upper part to the lower part.

porta1 porta2 porta3 porta4 porta5 porta6 IMG_20140208_142649.resized

So there you have it – Porta-Pi! Stories like this make us very proud of the opportunities made for young people to become makers and engineers through Pi projects, as well as a gateway to STEM activity and career forming. Thanks to Jayme for providing instructions for us to share (we love sharing!), and thanks to David Whale and all others involved in guiding Jayme through his new passion.

Here’s a picture I took at the Jam:

Jayme holds his Porta-Pi – and there’s Alex from RasPi.TV for scale

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