So, I had come across this project: http://www.instructables.com/id/LapPi-A ... i-Netbook/ a long time ago and really wanted something like this, but it was far too expensive (guy said it was over $300 US). The other methods of using my pi didn't really suit me as I'm on the move a lot and wanted to take my pi with me without being tethered to my outlet or monitor. I run Kali Linux on my pi and the portability factor really becomes an issue (no I'm not using it for evil, I work in IT security).
I am also not the most skilled with electronic configurations and wiring, but I have some basic knowledge that I used.
This made my criteria: Portable, Cheap, Easy to Build. I managed to find a way to do this through piecing together a lot of different guides. And this is what I have:
$16 wireless Keyboard & Mouse combo (chose this for comfort and its rechargeable)- http://www.amazon.com/gp/product/B00B99 ... UTF8&psc=1
$10 wifi adapter (not required, but nice to have)- http://www.amazon.com/gp/product/B003MT ... UTF8&psc=1
$30 7 inch screen (can get a $20 4.3" screen if size is not a concern)- http://www.amazon.com/gp/product/B007SL ... UTF8&psc=1
$20 2-2600mah power banks (come with usb cable)- You can find these in a variety of places and prices, just choose what suits you
$6 micro usb splitter- Again, variety. Find what suits you
$2 switch- just grab one that requires low voltage
$2 foam board- for the prettiness, choose the color your heart desires
$0 old usb cable for an old phone, cut the end off to use just the usb portion
and lastly $10 for the case, which case with a rotary tool kit I used to modify the case- http://www.walmart.com/ip/Ultra-Steel-M ... e/29096383
Total: $94 USD
I started by taking the rotary kit out of the case and hallowing out the bottom. There was foam in the bottom of the case that was surrounding the tool. I pulled this out and saved it for later to use as padding for the pi.
Then I took the casing for the lcd and used screws to mount it into the top portion of the case.
The lcd I bought was for a car, so it came with a long video cable. I took this and cut off several feet, stripped the ends and wired them back together. I just used duck tape very carefully to get it all back together, however, if you want to spend a few dollars and get heat shrink tubing it might be better.
I then took the usb portion I hacked off an old cable I had for an out of date device and stripped the ends. It contained a white, green, black, and red wire. The lcd came with stripped ends for power already a black (ground), red (power), and green (reverse sensor), which I snipped off along with the green and white ends from the usb. I then connected the red wires and the black wires together. Plugged it in and it worked perfectly because the screen is set up for 12v cars, but only actually requires 5v. Packed these into the top portion of the case as well.
I then cut the foam padding on the bottom of the case to accommodate the battery pack. Then I whipped out the rotary tool and cut two holes in the bottom portion of the case (yes I know I should've done this before, but I forgot).
Hole 1: in the back of the case for the micro usb splitter, which will be used to charge both battery packs
Hole 2: in the location near the ethernet jack of your pi, in case wifi isn't an option. On that note, I highly suggest pulling the locking tab off your ethernet cable to make it easy to attach and remove.
Then I hooked up the video cable and power to the pi and tested the operation and it went well!
This picture doesn't quite represent on account of the forgetting, but you get the gist.
I then split the red wire on one of the power bank usb cables and put the switch in the middle (again using duct tape, I know I know). Then attached the splitter to the charging points on the power banks and fed the end through the hole I cut out in the case.
I made sure there was enough room for all the parts and storage space for additional cables and the keyboard. I preferred not to build the keyboard into the case.
Lastly, I cut pieces of the foam board in the size of the case and cut the appropriate notches in the foam for cables to go through. Cut left over foam pieces from the bottom of the case to pad around the pi and battery packs. Then I used a left over piece of usb cable to fasten a handle to pull the foam off. The picture was taken before I fed the switch through the foam, but its pretty accurate.
Used the rotary tool to add a necessary cheesy design...
And TA-DA....portable raspberry pi for under $100