ADC0831 is an 8 pin IC with 8-bit serial data output (for more detail about ADC0831 refer to Interfacing ADC0831 with ATmega16). To receive the output from ADC high to low pulse is given at CS (chip select) pin of ADC form controller. ADC requires delay of two clock pulses before starting data conversion. At the second clock cycle, ADC sends a ‘0’ bit to the controller which indicates that the upcoming bits are the data bits.
ADC needs eight clock pulses to send 8-bit digital output. This digital data is received bit by bit and stored in a variable. The data is converted to its corresponding ASCII value and sent to LCD for display. The connections of LCD with microcontroller are shown in circuit diagram. The analog signals are generated by at a variable resistance (preset) which is connected to input pin of ADC0831.
1. Initialize LCD.
2. Send a high to low pulse to CS pin to initialize conversion.
3. Send two clock pulses.
4. Receive the data bits by one by one and store it in a variable.
5. Display its corresponding decimal value on LCD.