Portable Electronics Kit

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After initially watching the Ben Heck Show Portable Dev Kit episode I thought “I could do with one of those - but a bit different.

 

You see, whilst the Dev Kit was great for boards that had a video output, it wasn’t so useful for my Arduino  -  I need something that I can use to program the Arduino as well as use to practice my Dev skills on . . .

 

I needed a laptop type sort-of-device!!

 

This being E14 meant I was never going to buy a laptop, plus a laptop has limited 'fiddleability', I needed to think of something bigger, better, more . . . . . . . . well, Element 14 ish.

 

I present my idea for a RPi 3 based Portable dev / electronics kit.  The Pi-IDE.

 

My first port of call was to finally dig out my long-unused laptop screen and source a driver board from eBay, I'm a long time advocate of these HDMI to LVDS drivers having discovered them many years ago. I needed to put my money where my mouth was at last - so I went-a-hunting.

 

Weeellllll, that didn't yield much fruit and time was marching onwards so I called in a favour from an associate who bulk buys TVs / Computers / White Goods and repairs them. A bit of haggling later (me offering him cash, him refusing) saw me the proud owner of an A Grade 17" LCD from a laptop.

 

Now I already hear the 'why not just buy the official 7" Pi touchscreen', well, as my years advance (I'm 50 in a few months) my eyes get a bit worse, and being a vain sort of chap (I rarely wear my Crocs out of the house) I don't have glasses.

Plus, I didn't need the touchscreen facility, and finally, the board I was planning on purchasing gives the option of HDMI / VGA / DVI-D / Composite Video Inputs - a nice choice if I'm honest.

 

So, on to the driver board, a quick search on eBay against the LCD Part Number turned up a cracker - for the princely sum of around £23 GBP delivered from China - one subsequently placed on order.

 

 

That's the beauty, placed between the super-cheap charity shop find wireless keyboard and the awesome screen. It's all placed within the donor briefcase I had no use for - until now!

 

A quick test and I was greeted by a plethora of Chinese characters and then a screen in standby.  This was (hopefully) because I hadn't plumbed in any video input . . . . I hoped. A quick order to CPC for some parts - HDMI Cable (super short) and other bits and bobs soon had me building whilst waiting for the arrival.

 

Onto the case, I had served me well back in my Military career - it was a gift from my long suffering wife when I reached the dizzy heights of Sergeant - since then, I had used it to store random electronics I sporadically purchased - time for a new lease of life.

 

Out came the 'non-branded', charity shop special rotary cutting tool (did I mention my wife used to work in a charity shop - I got some good bargains there), and the hacking began.

 

 

Ohh, look, the screen JUST about fits! Excellent!

 

To mount it, I scratched my head and 3D printed various support attempts here but finally settled on hacking a rectangle out of a spare sheet of acrylic (charity shop cheap picture frame this time) and figuring a way to mount the screen to the back.

A quick (for me) dabble in Fusion 360 and printing them on my FlashForge Creator Pro  and the screen was affixed firmly to the sheet.

 

 

I DID have to wait for the fixings - that order (plus other important bits I didn't know I needed - until I needed them) were badly delayed due to our unexpected(?!?!) snowfall! A quick dash to the local hardware store and I managed to grab just enough to keep me (kinda) on track.

 

Now for the control panel, the panel itself is on a short ribbon cable and, with some standoffs, some 3D printed button extensions and a bit of luck I managed to mount it just below the screen and to the left - what do you think?

These extensions were later replaced with better, white ones as I intended to wrap the clear acrylic mount in black vinyl - I have done this bit it's not great. Wish I'd left it clear now! Oh well, onwards and upwards.

 

Next, lets get this all dropped into the upper half of the case, I 3D printed some angle brackets (this time sourced from Thingiverse - that saved me some time) and figured out a way to to get them to stay attached to the briefcase. Hot met glue worked until I touched it, roughing up the surface worked for a bit longer but, as my M3 fixings had finally arrived, holes were drilled and the angles screwed in place!

  

These, screwed onto here, (2 each side and one at the top).

 

It's in!! yay, time to mount the LVDS driver and get it all wired up, that right hand picture (or lower - depending on how the images show) has the driver in place, it WAS originally under the control panel - but unfortunately, after hacking a hole in the (now defunct and removed) compartments that used to live below the screen, I discovered the attaching cable didn't reach!!

 

DOH!

 

Re-siting the board further to the centre was tried, but I finally opted to place it on the right lower edge of the screen. Also, I have popped two bolts thru the acrylic and into the lower brackets to stop it swinging around.

 

Time to drop in the RPi 3, but first a case. Thingiverse again (yay), have I mentioned how cool it is to have a 3D printer for this kinda thing? No? Well, it IS.

 

Case printed and Pi slotted into place. As you may be able to spot, the screen surround is now black and the button white, pops nicely doesn't it!

 

 

This is where things started to go off-piste a little, I focussed too much on the aesthetic and not the construction of, useful things like wiring and stuff!

 

Here is how I finally decided to make the screen aperture look prettier (yeah, really! With so much left to do).

 

 

They have been carefully trimmed and glued - they do now fit properly and the overall effect is not too bad.

 

Back to it, a 12V spare supply has been pressed into service, it sports a healthy 5A current rating, and the screen drags a whole 700 mA at full bore - did I mention it has the LED backlight and not Cold Cathode Fluorescents - energy saving for the win.

 

This supply not only drives the LCD, but a quick trip to B&M Homestores netted me a 12V to 5V USB 'lighter socket' plug for the car. I opted for one with a 1A and 2.4A output! That should be just great for the Pi 3.

 

I had also purchased a Logic 3  11,400 mAh power pack and tried a Buck-Boost regulator to wazz it up to 12V for the screen, that would have been excellent, but unfortunately, the cheap buck-boost regulators weren't up to the job, I could get 12V out, but as soon as I loaded it with a bit of current the output collapsed. The screen just flashed on and off annoyingly.

 

I have got a 10 AA battery pack for a future experiment, but tried it with partially charged NiMH 2.4 Ah batteries - this should give me about 3 hrs of use at 700mA - but I got about 10 mins and gave up for now.

 

A future development is a 12V pack (from salvaged 18650 cells) and the 11,400 mAh power pack, this should give me proper portability and use on-the-go. Until then, it's going to have to be plugged in.

 

A 3D printed case for the USB socket and I was getting close.

 

 

 

It's now 04:38 on Saturday morning, we get a phonecall from a close friend - she's in labour - so we're off over there. The usual stuff goes on and Saturday is spent in hospital - no work on the kit, 1:30 Sunday morning and we're off home - eat / sleep / get up 5 hrs later, shop for new baby and mum, hospital again. Leaving Sunday night about 22:30, bed.

 

Monday, up at 6:30, I go to work, my better half to the hospital, I go from work to the hospital and then home to bed. Tuesday the same, Wednesday - well, you get the picture.

 

So there it is, I'm still trying to finish it, I'll update this as I progress, but for now I have to assume I'm well out of the running.

 

I'm not even sure I'm in time, but you know what? I'm over it.

I've spent many hours over the last few days with a gorgeous baby boy and, well, everything else kinda pales a little in the face of that.

 

SO, thank you for reading this, the last bit isn't meant as an excuse, I should have got this done earlier, but it is why I still haven't finished.  Not the baby, but my lack of planning and, sometimes drive.

 

To those who have completed, well done and I wish you all luck.

 

Here are some final pictures of my current progress.

 

Enjoy.

 

The 'Project14' Logo - rendered in Fusion 360 and printed, ready to be attached to the finished project.                                   Screen surround in - looks ok doesn't it?

Project 14 Logo 3D print 

 

A rather snazzy 3D printed Arduino 'Portable Dev Kit' I purchased from cults3D and printed myself.

 

 

The 5V supply mounted and Pi 'plumbed in', the worlds 'shonkiest' wiring - wrapped in masking tape as I can't find the garage key for the heat shrink or insulation tape.

Keyboard in (just), mouse in and attached, Grove Arduino Starter Kit, GPIO Breakout for the Pi and plugged into the mains.

 

"I'm wearing that brooch you gave me . . . . "

 

 

Not sure if it deserves the Project14 badge, but dammit, it's on there now!

 

A look inside - (I dumped the 3 vids - awful)!  Grove Starter Kit, Switech X27 Stepper (1 of 10) & 3V Adafruit Trinket.  Shonky wiring (to be replaced), Breadboard with 5V / 3.3V output, various inputs.    Rasbian Desktop with Pixel, Arduino IDE installed (plus others).

 

   

 

Some more bits for the kit - else it's just a rather clunky 'Laptop'

 

 

And finally, an awful (short) video, Fingers crossed!

 

 

 

Thanks for looking and, goodnight!

 

Andrew