TTab Portable Raspberry

Last crawled date: 3 years, 10 months ago

I needed a small laptop with GPIO and I made this raspberry tablet composed by the following main components:

- Raspberry Pi4 (pi3 is also good)
https://www.raspberrypi.org/products/raspberry-pi-4-model-b/
- 10"color monitor with capacitive touch screen
http://wiki.sunfounder.cc/index.php?title=10.1_Inch_Touch_Screen_for_Raspberry_Pi
- battery 12Volt 6000mA/h
- nr. 2 Speaker (Stereo output from display)

The box is designed with ventilation grids and an external USB port (in my case USB3)
and a DIN connector are made available with some signals taken from the raspberry's GPIO port and from the ADC converter.

To monitor the battery status I connected a resistive divider (100K / 50k) to the
12volt battery and the divider output was connected to an ADC (I2c) converter ADS1115 to read
the battery voltage and calculate the remaining charge.

to read the battery status I made the following python code:

----
# Author: TeoG
# License: Public Domain
import time
import datetime
# Import the ADS1x15 module.
import Adafruit_ADS1x15

# Create an ADS1115 ADC (16-bit) instance.
adc = Adafruit_ADS1x15.ADS1115()
GAIN = 1

print('Press Ctrl-C to quit...')
while True:
value = adc.read_adc_difference(0, gain=GAIN)
now = datetime.datetime.now()
dt_string = now.strftime("%d/%m/%Y %H:%M:%S")
volt = 0.0003891797 * value
#print('Channel 0 minus 1: {0}'.format(value)+" "+dt_string)
print('{0}'.format(value)+" "+dt_string+" -->"+'{0}'.format(volt))
file1 = open("batterylog.txt","a")
file1.write('{0}'.format(value)+";"+dt_string+";"+'{0}'.format(volt)+"\n")
file1.close()
# Pause for half a second.
time.sleep(60)
-----

About SO for Raspberry (in my case Rpi4 4GbyteRAM) I've installed Raspian Buster (2020-02-13-raspbian-buster-full) with
a virtual keyboard: sudo apt-get install matchbox-keyboard


The construction of the case took a lot of hours of planning and the creation of some unsuitable prototypes that I had to throw away.

I thought to creating on the upper side of the case a slot with a panel with the main connectors housed
(in my case DIN GPIO power supply and switch). However, this closing base can be customized as you want to house connectors
or extensions coming from the raspberry ports and or camera housing could also be made.

I say that the autonomy of the raspitab is excellent and the usability with rpi4 and touchscreen is very good !!.

In the project files are placed: a draft schematic of connection and some photos.

TODO
1)the box with the levers of the LCD buttons is a bit unstable and needs to be redesigned
2)make a TPU bumper

PAYPAL DONATION:
if you want to support this project you can make a welcome donation here: https://tinyurl.com/yamkrgyx
As a gift for the donation received the CAD source files of all printable parts of the projects (Freecad source 0.18)

List of components used (amazon / ebay):
ADS1115 Modulo ADC 16 Bit I2C 4 canali con amplificatore Pro Gain per Arduino e re Pro Gain
per Arduino e Raspberry Pi
https://www.amazon.it/gp/product/B07DFX9Q4G/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

10 PEZZI mini JST 2.0 millimetri PH 4Pin 26AWG maschio femmina Connettore Cavi spina 300 mm
https://www.amazon.it/gp/product/B07FZ4Z73P/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

12Pcs 5.5mmx2.1mm，5.5mmx2.5mm Connettori DC a pannello jack,2Pcs alimentazione DC presa ，Per connettore femmina da pannello
Venduto da: RUNCCI-YUN
https://www.amazon.it/gp/product/B07PXQLJL9/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Adattatore da pannello HDMI femmina a HDMI femmina, confezione da 5, colore: Nero
https://www.amazon.it/gp/product/B07P7PBCC8/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

CAT6 RJ45 maschio a femmina vite panel Mount Ethernet LAN prolunga cavo di rete 1 m
https://www.amazon.it/gp/product/B01MD2AYSW/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

2 di Bolonking, pannello di montaggio a filo con cavo, con presa USB 3.0, supporto per cruscotto,
montaggio a incasso, per auto, barca, moto
https://www.amazon.it/gp/product/B07DDB2L5N/ref=ppx_yo_dt_b_asin_title_o05_s01?ie=UTF8&psc=1

2pcs Arduino Speaker 3 Watt 8 Ohm cavità Singola Mini Speaker cavità Full-Range Mobile
Portatile Macchina pubblicitaria Speaker con 11mm Lunghezza L
https://www.amazon.it/gp/product/B07FT9CFY4/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

RASPBERRY PI 4 Modell B 4GB ARM-Cortex-A72 4X 1,50 GHz,
4 GB RAM, WLAN-AC, Bluetooth 5, LAN, 4X USB, 2X Micro-HDMI
https://www.amazon.it/gp/product/B07TC2BK1X/ref=ppx_yo_dt_b_asin_title_o07_s01?ie=UTF8&psc=1

SUNFOUNDER Raspberry Pi 10.1" Display Touchscreen 10.1 inch IPS LCD HDMI 1280x800
for Raspberry Pi 4B 3 2 Model B And RPi 1 B+ LattePanda Beagle Bone
https://www.amazon.it/gp/product/B0776VNW9C/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

PACCO BATTERIA 12 VOLT 7000mAh 7Ah 12V RICARICABILE ALTA QUALITA' LITIO F2D4
https://www.ebay.it/itm/PACCO-BATTERIA-12-VOLT-7000mAh-7Ah-12V-RICARICABILE-ALTA-QUALITA-LITIO-F2D4/122412296460?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

Varie
m2.5 x 30 mm presa esagonale testa con zigrinatura tappo viti bulloni dadi set 50PCS
https://www.amazon.it/gp/product/B015A32OC8/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1