Raspberry Pi 7" Touchscreen Tablet

This instructable demonstrates how to build a rechargeable lithium ion battery charged Raspberry Pi touchscreen tablet. This project was discovered on Adafruit.com and the instructable goes into depth on how to recreate this project. This instructable seeks to provide an entry level explanation of building electronics.

DISCLAIMER: Complete this project in a Makerspace at a soldering station with an industrial exhaust fan as the project involves the burning of plastic.

A Google Maps Search for "Makerspaces" will show the Makerspaces near you. There is also this map resource from the Make: Community

Supplies

7" Touchscreen Display - $64.00

Raspberry Pi 3 or Above - $35.00

Adafruit PowerBoost 1000C - $19.95

2500mAh Lithium Ion Polymer Battery - $14.95

200mm Flex Cable - $1.95

SPDT Switch - $0.95

Wire Strippers - $4.72

Screwdrivers - $5.99

Soldering Iron Kit - $22.99

Solid Core Wire - $15.95

Zip Ties - $6.99

M3 x .5 x 6M screws - $1.00

#2-56 3/8 machine screws - $7.05

32GB Micro SD Card - $8.98

Helping Hands - $7.93

Factoring $20.00 in shipping and taxes the total cost to build the tablet is approximately $250.00

This price includes procuring basic microelectronics hardware and assumes that you start the project without any of these supplies.

The cost of building will be less depending on if you already have a soldering iron, wire strippers, screw drivers, zip ties, helping hands, and solid core wire.

Materials such as Soldering Irons, wire strippers, helping hands etc. can be found at your local Makerspace and used free of charge

Most Makerspaces also offer 3D Printing Services or have 3D Printers that you can print on inexpensively

The cost of building will be more depending on if you have to pay for a 2nd party for 3D Printing.

Step 1: Download Raspberry Pi Noobs Installation

Download NOOBS

Go to the NOOBS Website

Download Raspberry Pi NOOBS Zip File, it will take approximately an hour to download

Format 32GB SD Card making sure that the drive is blank with no files on the card

Upload the files from the Noobs Zipfile: NOOBS_v3_2_1 to 32GB SD Card

Eject SD Card

Step 2: 3D Printing

Download STL files from Thingiverse: https://www.thingiverse.com/thing:1082431

Download Ultimaker Cura 3D Printing Tool to convert the file to 3D Printable Gcode format: https://ultimaker.com/software/ultimaker-cura

Convert STL Files to Gcode in the Ultimaker Cura Software

The Gcode files can then be input into a 3D Printer and printed

A quick Google Maps search for Makerspaces should show Makerspaces near you where you can print your files inexpensively, often only charging for the amount of filament used. There are usually options to email the files to the Makerspace and they will print them for you. This requires approximately three weeks of turnaround time depending on location.

Many local libraries have makerspaces as well. A map of makerspaces can be found here

If you are unable to find a Makerspace then there are 2nd party printing services such as 3D Hubs and Shapeways that can print the files for you at a premium.

I found that Instagram is home to many grass roots 3D Printing Services and these services are less expensive than 3D Hubs or Shapeways.

For this project I commissioned @3d_unclephil from Instagram for the printing of the tablet case and the result was great.

Step 3: Insert MicroSD Card Into Raspberry Pi and Attach 3D Printed Frame

Insert MicroSD Card with NOOBS Files downloaded newly onto the drive into the Rasberry Pi

Unscrew screws from the Touchscreen Display Driver - this can be accomplished by unscrewing screws with your fingers

Remove ribbon cables from Touchscreen Display Driver - this can be accomplished by using your fingernails to push open the plastic ribbon cable holders and removing the ribbon cables from the Touchscreen Display Driver

Attach 3D Printed Frame

Step 4: Mount the Frame Bracket to Display

Use a No. 1 Precision Screwdriver and two M3 x 6M screws to mount the Frame Bracket to Display

Step 5: Solder 5V Power and Ground to Touchscreen Adapter Display Board

Cut two lengths - 5" - of Solid Core Wire and strip the ends

Using the Helping Hands to stabilize the Touchscreen Adapter Board, solder the wire to the 5V and GND GPIO (General Purpose Input/Output) pins

Soldering Instructables will help you if you do not yet know how to solder: https://www.instructables.com/id/Soldering-101%253a-Lesson-1%253a-Tin-the-Tip/

Step 6: Connect Ribbon Cables to Touchscreen Display Driver

Connect the Wide Ribbon Cable to back to Panel 2 on the backside of the Touchscreen Display Driver

Connect the Mini Ribbon Cable to Panel 1 on the front of the Touchscreen Display Driver

Be sure lock the plastic Ribbon Cable Lock back into place on both Ribbon Cables

This step takes slight patience to get the ribbon cables locked back into place

Step 7: Connect 200mm Ribbon Cable and Mount Touchscreen Display Driver to Frame

Connect 200mm Ribbon Cable to Touchscreen Display Driver

*The M3 x .5 x 6M screws didn't quite fit so it was necessary to burn the plastic mounts on the Touchscreen Display Driver*

DISCLAIMER: It is imperative that you are in a well ventilated space underneath an exhaust fan when completing this step and this project. Many Makerspaces have exhaust fans at the soldering stations.

Step 8: Solder Connections and Mount PowerBoost 1000C

Cut, strip, and tin(add solder to the ends of wire) the ends of four lengths of solid core wire - two approximately 2" and two that are 4"

Pull USB port off of the PowerBoost1000

Solder the wire to the inputs/outputs of the PowerBoost1000 - See circuit diagram at the beginning of the Instructable as well as above photo

Step 9: Solder SPDT Switch to PowerBoost1000 and Mount the PowerBoost1000 to the Frame

Solder solid core wires from the PowerBoost1000 EN and GND to the SPDT Switch

*I misplaced my SPDT switch so the photo above shows a different switch, but the concept remains the same*

The GND wire goes to one of the two ground prongs on the left OR right side of the SPDT

The EN wire goes to the center prong

Mount the PowerBoost1000 to the Display Frame using two .5 X 6M Screws

This may require soldering of mount holes on PowerBoost1000 to allow for screws to fit

Step 10: Mount Raspberry Pi to Display Frame

Mount the Raspberry Pi to the left side of the Display Frame next to the Touchscreen Display Driver using two .5 X 6M Screws

Step 11: Mount LiPo Battery to Frame

Ziptie the 3.7v LiPo Battery to the Battery Frame using the holes in the Battery Frame

Mount the LiPo Battery and Battery Frame to the Touchscreen Display Driver using two .5 X 6M Screws

Step 12: Solder Solid Core Wire Connections to Raspberry Pi and Connect LiPo Battery to PowerBoost1000

Make sure all Solid Core Wire ends are tinned

Solder the positive wire from the PowerBoost1000 to GPIO #2 on Raspberry Pi

Solder the negative wire from the PowerBoost1000 to GPIO #6 on Raspberry Pi

Solder the 5V wire from the Touchscreen Display Driver to GPIO #4 on Raspberry Pi

Solder the Ground wire from the Touchscreen Display Driver to GPIO #9 on Raspberry Pi

Connect the LiPo Battery to the PowerBoost1000

Step 13: Connect 200mm Ribbon Cable and Mount SPDT Switch

Connect the 200mm Ribbon Cable from the Touchscreen Display Driver to the Raspberry Pi with metal strips facing inward, ensuring that the Ribbon Cable Lock is secured

Mount SPDT switch to shelf on the Display Frame Enclosure

*If the SPDT does not fit securely on the shelf then cut or burn material until the switch fits. If the switch is loose then use glue to secure it in place*

Step 14: Test Functionality and Mount Enclosure

Review steps for accuracy

Switch on SPDT Switch to test the Touchscreen Display

*The Raspberry Pi should switch on and it should show NOOBS installation steps*

If the power turns on then switch the Raspberry Pi Tablet off and Mount the Enclosure using four #2-56 3/8 Machine Screws

Step 15: Install Raspbian

Turn the Raspberry Pi Tablet on

You will see a NOOBS Raspbian Installation Screen

Check the NOOBS Raspbian check box and select install

A prompt will tell you that all Operating Systems will be overwritten, choose yes to confirm

The operating system will begin installing when it is finished a message will tell you when that the Operating System has installed successfully, select ok and the Raspbian OS will begin to run.

You will be directed to a Raspberry Pi Desktop Setup.

Thats It! Your ready to start using your Raspberry Pi Tablet.