Design of digital display system for ISFET pH sensor by using PIC microcontroller Unit (MCU)

This paper describes the digital display system using peripheral interface controller (PIC) microcontroller. The research is conducted in-house at the university microelectronic and nanotechnology research cluster well equipped with electrical instruments and electronic equipments. This paper focuses on the design of schematic circuit for digital display system using PIC microcontroller and development of programming for PIC microcontroller. Digital display system is the most popular technology and most compatible with the embedded system devices. The system is a variable device that is easily adapted to a wide range of agriculture, chemical, biochemical and biomedical measurements. The operation of this system is based on the analogue value in term of electrical conducted by ionic sensitive field effect transistor (ISFET) pH sensor and display the captured data using PIC microcontroller. As a result of this process, the threshold voltage of the ISFET is modulated and it will be converted as the value of pH on digital display system. This paper also highlights the research on ISFET and deals with the fundamental issue: fabrication of ISFET using CMOS technology. The ISFET compatible layout will be presented and the ISFET process flow will be discussed.