BUY ADC7815 https://www.utsource.net/itm/p/1527442.html
Autocalibrating, 4-Channel, 12-Bit ANALOG-TO-DIGITAL CONVERTER
The ADC7815 is an 8-bit analog-to-digital converter (ADC) with a serial interface. It is a low-power, low-cost device that is ideal for applications requiring high accuracy and low power consumption. Features: 8-bit resolution Low power consumption Serial interface High accuracy Low cost Applications: Data acquisition systems Automotive systems Industrial control systems Medical instrumentation Process control systems (For reference only)