Question: In PSoC1 or PSoC3 can we use only 4 data lines to drive the LCD. Also, should these pins be connected consequently.
Answer: In PSoC Designer and Creator, the LCD APIs uses only 7 bits, the description is as below:-
4 for data lines (D4-D7)
1 for Enable.
1 for Read/Write (RW)
D0-D3 lines of LCD should be grounded.
These pins must be connected consequently on a single port.
i.e. on a single port, first 4 pins should be data lines, 5th pin as Enable, 6th as Register Select and 7th as Read/Write