Raspberry Pi 1605 LCD Display

Provide Power to the LCD module:

LCD	Power	Description
VDD	5V	board power
VSS	0V	board ground
RW	0V	read/write select, 0V for write only
A	5V	backlight power
K	0V	backlight ground

Connect the potentiometer (trimmer) to the LCD module:

LCD	Input	Description
V0	POT (middle pin)	control the contrast of the LCD

Connect the LCD to the Pi in 4 bit mode:

LCD	BMC	BOARD	Description
RS	GPIO07	26	register select HIGH store in data register LOW store in instruction register
E	GPIO08	24	write enable, write data to register when ready
D4	GPIO25	22	4 data lines…
D5	GPIO24	18	…send 4 bits at a time…
D6	GPIO23	16	…4 high bits …followed by 4 low bits…
D7	GPIO18	12	…complete the 8 bit character or instruction

CircuitPython

Install the required packages from AdaFruit [01]…

# install required Python packages
apt-get install python3 python3-pip
pip3 install adafruit-blinka adafruit-circuitpython-charlcd

Simple hello world example…

#!/usr/bin/env python3

import board
import digitalio
from adafruit_character_lcd.character_lcd import Character_LCD_Mono

lcd_cols = 16
lcd_rows = 2
lcd_rs   = digitalio.DigitalInOut(board.D7)
lcd_en   = digitalio.DigitalInOut(board.D8)
lcd_d4   = digitalio.DigitalInOut(board.D25)
lcd_d5   = digitalio.DigitalInOut(board.D24)
lcd_d6   = digitalio.DigitalInOut(board.D23)
lcd_d7   = digitalio.DigitalInOut(board.D18)

lcd = Character_LCD_Mono(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_cols, lcd_rows)

lcd.clear()
lcd.message = 'Hello World...'

C

Install WiringPi packages [02]…

# install the required C library
apt install wiringpi

# list all GPIO pin values
gpio readall

# compile the example
gcc -lwiringPi -lwiringPiDev -o hello_world hello_world.c

Simple hello world example…

#include <stdio.h>
#include <wiringPi.h>
#include <lcd.h>

#define LCD_COLS  16
#define LCD_ROWS  2
#define LCD_MODE  4   // use 4 data lines
#define LCD_RS    26
#define LCD_EN    24
#define LCD_D4    22
#define LCD_D5    18
#define LCD_D6    16
#define LCD_D7    12

int main() {
        // Initialise WiringPi
    wiringPiSetup();
        // Initialise the LCD
        int lcd;
        if (lcd = lcdInit (LCD_ROWS, 
                           LCD_COLS, 
                           LCD_MODE, 
                           LCD_RS, 
                           LCD_EN, 
                           LCD_D4, 
                           LCD_D5, 
                           LCD_D6, 
                           LCD_D7, 
                           0, 0, 0, 0)) {
                printf("LCD initialise failed\n");
                return -1;
        }
        lcdClear(lcd);
        //Position cursor on the first line in the first column
        lcdPosition(lcd,0,0);
        //Print the text on the LCD at the current cursor postion
        lcdPuts(lcd, "Hello, world in C...");
}

Reference

[01] Drive a 16x2 LCD with the Raspberry Pi
[02] How to Setup an LCD on the Raspberry Pi and Program it With C
[03] Drive an LCD 16x2 display with Raspberry Pi
[04] Interfacing 16x2 LCD with Raspberry Pi using GPIO & Python