Raspberry Pi 7" Handheld Tablet

So this is the tablet version of the Rasptop 2.0 (https://www.thingiverse.com/thing:2859679) and it uses all the same parts, except no keyboard and one less USB port.

Just 2 parts, it's screws together with M3x10 self threading screws for the two halves and M3x25mm screws hold in the screen.

#Some config notes

If you get the voltage warning symbol you can disable it with this line in the config.txt

avoid_warnings=1

Also, I like to have the lights on my Pi setup so the red light is only on when the machine is off, like if you tell it to shutdown the red light comes on when it's safe to power down:

dtparam=pwr_led_trigger=none
dtparam=pwr_led_activelow=off

And finally I like the green light to pulse based on system load. This is called heartbeat:

dtparam=act_led_trigger=heartbeat

#BOM

• 7" Capactive Touch Screen with 1024x600 Pixels or Pi Foundation Screen

• Flat Flex HDMI Cable Extension

• You will need about 30cm of flat cable to run HDMI

• HDMI Rasppberry Pi Screen Connector

• 20AWG Silicone Wire

• USB Ends

• Slide Switch

• A source of a battery

• Soldering Iron, Flux, Solder

• 220mmx220mm capable 3D printer

• Several Hours of Time

• Asus Tinkerboard, Raspberry Pi 3 B+, Raspberry Pi 4 B+, or other Single Board Computer that fits the RPI form factor.

• Some cooling to fit your computer. I used active cooling on my latest builds. This fan works well.

• 2S charger 9-15v input

• 2S Balance and Protection Board

• DC to DC Buck Converter 5amps

• 2S Charger Indicator

• Small MOSFET Module

• I used a 5.5mmx2.1mm DC Barrel jack mounted just above the USB input with a hole drilled there. I picked these because they are really small and I just super glued it in.

• 9 volt 5amp Power Supply, using 9v instead of 12v greatly reduces heat in the charger circuit

• Matched pair of cells.

#Raspberry Pi 4B fits!

#If links are dead:

Let me know or search the item. The battery one keeps changing. You want a 10,000MAH booster pack with a LiPo battery. These are often sold as slim type about $10 USD.

#This uses the 2S 7.4v Power System

Use this one please. It provides the best results and the longest battery life. Used with a 9 volt charger it charges up quickly and safely with little excess heat.

#How I wired it:

Starting with the batteries I wired them each with a length of 20ga silicone wire then on the balance board you connect positive from one cell and negative from the other to the B+ and B+ tabs on the balance board. The leftover positve and negative wire both go to the BM pad together making a series connection.

The P+ and P- from the balance board then go to the MOSFET input side. This is also where the positive and negative from the charger board attach so it can charge with the switch off. I used 24GA wire from the charger to the cells. I also used 24gs from the DC barrel jack to the charger board.

You need a wire from Battery + to go to the switch as well, this can be 24ga or even smaller. and the wire coming back from the switch goes to the input signal on the MOSFET module.

On the output of the MOSFET module connect the battery level indicator and the DC to DC converter board so they come on when the switch is on.

#Be sure to set the voltage before connecting anything to the DC to DC converter!

#No more than 5.2 volts. Set to 5.1 volts!

I put the Micro USB in still and just wired it directly to the 5v side of the system so I can plug power in there and not use the battery to run it on the bench or something.

So in a test with Ubuntu 18.04 MATE and Chromium browser running Google Play Music I got 14.5 hours of battery life on a full charge playing over bluetooth speakers and doing other random things on this battery arrangement.

#14.5 hours!

I have not yet built this myself. I will soon.

#Thank you!

• Update 6/3/2020 Updated everything. Made small improvements, made it thinner, stronger and easier to hold. Added my logo to the back and reuploaded parts.