This sensor measures differential pressure comparing to atmospheric so when there is no pressure applied it shows 0kPa. The base board has all the basic circuit to run the PIC.
If the width is higher than 50uS it indicates a high signal and ACC. The conversion time required depends on the type of ADC, the applied clock frequency, and the number of bits being converted. Only 3 of its pins are used. R4 sets the contrast of the display.
A 32-byte segment of this 128 byte memory block is bit addressable by a subset of the 8051 instructions, namely the bit-instructions. C2 is just a decoupling capacitor. It is defined as exchange of Input or output data between sensor and PIC microcontroller or other devices.
This is thin-film metallization, and bipolar processing to provide an accurate, high level analog output signal that is proportional to the applied pressure. This signal can be used to alert the computer to read in the binary data. Good work.
R5 limits the current through the back light LED. For this purpose ADC is used.
The communication protocol with the sensor and the microcontroller is already explained. The basic communication scheme is given in the image below. Analog-to-digital conversion is a more complicated process than for the DAC , and the hardware requires some conversion time, which is typically in the microsecond range.
So we need to just concern about the first 8 bits of data, that is the integral part of the relative humidity data. Input to its equivalent binary output.
Then P3. Capacitive method is used for sensing the humidity and a thermistor is used for measuring the temperature. JB P3.