The Raspberry Pi. Everyone's favorite SBC (single board computer). 1gig of RAM and a 900mHz CPU packed into a credit card sized computer. It's the base for hundreds of different projects and today I'm gonna show you how to turn it into an awesome little laptop! This project has been done before by others but in larger housings and not to my personal liking so I took bits and pieces from other's Raspi laptops and made my own :D
This project is most like Instructables member SilverJimny's "LapPi" (seen here) which makes use of an aluminum 10"x6.5"x4" case and quite a few extra components.
Most of the parts I used I already had lying around the house, including the case I used (6"x6"x2 5/8")
1- 6"x6"x2 5/8" makeup case
1- Raspberry Pi B 2
1- 4.3" 12v LCD screen
1- RCA Female jack
1- 3.5mm Audio jack
1- 3.5mm A/V cord
1- USB female port
1- Push button switch (harvested from old computer tower)
1- SPDT switch (harvested from old audio amp)
1- Laptop fan or other CPU fan (optional)
3- Blue LEDs
3- LI-ION cell phone batteries
1- USB LI-ION battery charger (harvested from old E-Cig charger)
1- 3V to 5V 500mAh step up converter circuit (from portable AA battery cell phone charger)
A few scrap pieces of wood & some nails
Old DVD cases (carboard or wood works also)
Solder & soldering iron
Phillips head screwdriver
Side Note: The LapBerry Pi isn't officially completed yet, next month I'll be placing an Amazon order for some extra parts such as an audio amp for internal speakers, a wireless keyboard/trackpad and some better batteries. Updates to this instructable will be posted as new steps and timestamped to keep everyone up to date :D
Step 1: Modify the LCD to Operate at 5v
DISCLAIMER: I am not responsible for any damage done to your LCD. Soldering small components can be very tricky and frustrating
I'm using a 4.3" LCD for this project and have modified it to operate it at 5v instead of 12v so I can power the screen and the Pi from one source. If you look at the Raspberry Pi forums, you can find a few threads on how to do this. Although all the threads are about 3.5" LCDs, the process is very much the same.
1) Open up your LCD and identify the 12v to 5v buck converter IC (little black rectangle with 8 legs)
2) Google the pinout for you 12v to 5v buck converter IC and locate the output pin and solder your 5v lead to it
3) Plug it in and turn it on!
If you did this all correctly you'll now have a 5v LCD! :D
Step 2: Mounting the Pi
I suggest using a ruler or tape measurer before making any modifications to your case so make sure everything is accurate.
1) Decide where you want your Pi to site and trace around it with a pencil
2) Cut out hole(s) in the side of your case for the USB & Ethernet ports
3) Fit you Pi into the hole you made and use the screw holes on the Pi to mount it to your case
I wrapped a little electric tape around the USB and Ethernet ports because the sides of the case are aluminum and the pins on the bottom of the Pi came dangerously close to touching it
Step 3: Mounting the LCD
I first created a backing for my LCD that I then mounted in the case, You can skip the backing as it isn't really necessary for mounting the screen, I only did it to bring the screen out a little bit. I had some scrap wood lying around and took a few small nails and just threw it together in a couple minutes then used some computer screws to mount the LCD to the backing, then I fit the backing into the case and put a screw on both sides to make sure it doesn't move
Alternatively you can skip making a backing and just screw the screen into the case but you may not want to do that depending on the depth of the case.
After mounting the LCD and the little control board I made a couple small holes in the top half and bottom half of the case to run the Input and power wires through to the Pi.
Step 4: Switches, Buttons, LEDs, Wires, and Jacks!
The Raspberry Pi has both HDMI and composite (RCA) A/V output. For this build, we're only going to use composite since the LCD is composite. I bought a 3.5mm A/V cable but it was way too long (6') so I cut it so there's less clutter inside the LapBerry Pi plus I get quite a bit of extra wire to stash for later projects! :D
The Raspi 3.5mm jack has a different pinout than most devices. Usually yellow=video, white=audio left channel and red=audio right channel however, on the Pi, yellow and red are backwards so the red lead is video and the yellow lead is the audio right channel. I used a spare 3.5mm stereo jack for the audio and a spare female RCA plug for the video. The LCD has 2 video channels so I could have used 2 RCA plugs, one for video input and one for video output but instead I Used one RCA plug for both video in and out which means the LapBerry Pi can dual output video on the screen and on a separate composite screen (TV, LCD, whatever has comp input) or you could plug your favorite video game system into the LapBerry's screen!
Again for this part, I suggest tracing the plug on your case before making any modifications so you dont end up accidentally making a hole too big for the ports. I used my X-acto to make the holes, just twisting it in a circle and it worked perfectly. after connecting the jacks to the 3.5mm A/V cable I super glued the jacks in place.
I'm hoping in the future to get an HDMI to VGA+RCA adapter so it can output to VGA or composite without having to open up the LapBerry to switch video modes.
Buttons & switches:
Originally I was planing on only using a single switch but that would mean the screen would constantly be powered whenever the Pi was turned on so I added a push button from an old computer tower for the screen's power. I was able to easily cut the holes with an X-Acto knife and just use some computer screws to mount them. I used the SPDT switch for the Raspi's power and the push button for the Screen's power.
I used a regular old 5mm blue LED for a power indicator, plugged into the 3.3v GPIO on the Raspi (I was too scared to solder to the actual power or activity lights on the Raspi).
Step 5: POWER!!!
Powering the pi:
The LapBerry Pi is completely portable with about a 3 hour or so battery life.
This was achieved with the use of LI-ION cell phone batteries. If you're like me, you probably have quite a few of these lying around. I used a 3.7v 2150mAH LI-ION for the Pi itself, plugged into the 5V GPIO pin. I've found my Pi to have about a 700mAh power draw but that will vary depending on the peripherals you attach to your Pi.
Powering the LCD:
Originally I had the LCD screen powered via the second 5V GPIO on the Pi but I found that the screen would repeatedly cut out on occasion for like .5 seconds which got really annoying after a while so I decided to give the screen its own power supply. For this I used two 3.7V 500mAh cell phone batteries wired in parallel so it outputs 3.7v at 2000mAh and connected them to a 3V to 5V 500mAh step up converter I harvested from a portable AA battery cell phone charger and wired to the screen. I put the batteries and step up converter in a small plastic case to keep them from moving about the laptop
Recharging the LapBerry Pi:
This is the fun part. Since the two power sources have different mAh ratings, they require being charged separately to avoid any issues.
I used an old USB E-Cig charger to charge the batteries and soldered male jumpers to the output and female jumpers on the two power supplies so I can switch which supply is being charged. I could've used a switch instead but I didn't have a proper switch nor the funds to buy extra components. All the extra components used in this project I have just lying around the house.
The USB charger had a male USB on it which wasn't very optimal for the laptop since the USB would have to stick out of the case so I soldered a female USB port in place of the male USB and mounted it in the back of the case with super glue and made a hole so the charger status lights were visible
Step 6: Cooling Fan (optional)
The Raspberry Pi is about 29°c or 30°c when you boot to the desktop GUI and can climb up to 50°c depending on what you're doing and shuts itself down around 80°c to protect components from overheating damage. Heatsinks and fans are used to keep the Pi from getting too hot. I don't have any proper sized heatsinks but I do have an abundance of fans so I dug through my collection and found this laptop fan from a Gateway NV54 laptop which seemed to be the most perfect fit. It sits comfortably on top of the USB ports and is the same width as the Pi and is practically silent :D
I attached a female jumper to the fan and used one of the 5v GPIO pins to power it it keeps my Pi about 12°c cooler. Next thing to do was figure out how to mount it!
I have a bunch of these stackable computer screws lying around so I decided to use a few of them to help support the fan and hold it in place.
Since blue LEDs are kind of my aesthetic, I thought it'd be cool to put a couple LEDs under the fan. I wired them in parallel, super glued them in place and made a small hole in the side of the fan to run the wires through. Blue LEDS operate at 3v-3.4v at about 20mA so I used the 3.3v GPIO to power them.
Step 7: Covering Up the LapBerry Pi
This is another fun part! Making the covers for the laptop's guts!
I had a few DVD cases that had no DVDs to go it them so I decided to take them and use them to make the covers. Originally I had made cardboard cut outs but they were just tacky looking. after I had the 6" x 6" squares cut out, I used a heated up X-acto knife to cut the spots for the screen, the screen's control board and the cooling fan. I didnt do a "perfect" job but for now they're fine! I may get bored in the future and redo them and make them look nicer.
I also made a small square hole in the cover of the top half for my Raspberry Pi Camera Module but my cable for it is 2" too short so until I order a longer one it's temporarily cameraless :/
Step 8: Adding Access to the GPIO (12/16/15 Update)
Not many Raspberry Pi Laptops have easy access to the GPIO pins and Im sure most of you are probably wondering how to access the GPIO with a fan sitting on top of them and for a little bit, I too was wondering how to access the GPIO without taking the laptop partially apart until I looked around my spare computer parts and found an old CD Drive and a ribbon cable and realized I could just make an extension cable.
Step 1:Modify the ribbon cable to fit the Raspberry Pi.
Depending on whats already connected to the GPIO you may need to modify the ribbon cable to fit the Pi. I had to cut mine on the 28th pin to get it to fit what was left on my GPIO pins. I also had to split the wires in half and layer them so the CPU still had airflow from the fan
Step 2:Remove IDE pins from old CD-Drive.
I dont have pictures for this part but its really simple, I just took some wire cutters and cut the IDE connector off the CD-Drive and cut off the unnecessary pins.
Step 3:Solder the connections.
At this point you should have one end of your ribbon cable cut of and exposed 1/8" or 1/4" of wire exposed on each line.
Tin the end of each connection with solder and solder each wire to the corresponding IDE pin. This can be a little tricky without a fine tip soldering iron and a steady hand. If you're still new to soldering, take occasional breaks and dont stress it, no one get soldering perfect immediately, it takes time and practice but once you get it you get such a sense of accomplishment
Step 4:Mounting the accessible GPIO
I toyed with a few different ideas of where to mount my GPIO extension cable including ticking out the backside of the LapBerry Pi but I eventually decided on mounting it in the upper left corner on the bottom half of the laptop for ease of accesibilty while coding on the LapBerry Pi plus theres no risk in leaving them uncovered when the LapBerry Pi is closed shut