TTab Raspberry Tablet

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 d