NRF51822 BLE battery voltage logger

BLE Battery Voltage Logger NRF51822 Bluetooth Low Energy module is simple solution to log 12V battery voltage and display voltage values in 0.96 inch color tft display . Information can be transferred with BLE interface to Android smartphone. BLE module: NRF51822 module 64k Color IPS 0.96 inch 80x160 TFT display module with ST7735 driver and SPI interface : Color IPS 80x160 ST7735 With KiCad I edited schematic diagram and printed circuit board for this battery voltage logger: KiCad printed circuit board design supports 3D model show, if exists component/module 3D model in KiCad 3D library (.wrl/.step). I designed also printed circuit board, but did not order prototypes. 3D images of design: KiCad 3D view of battery monitor NRF51822 software was developed using Arduino IDE with NRF51 library package by Sandeep Mistry : https://github.com/sandeepmistry/arduino-nRF5 First thing is to program S130 softdevice (BLE firmware to NRF51822). I used ST Link V2 for programming...