LCD screen

raspi-config > Advanced Options > SPI (enable SPI)
apt-get update
apt-get install build-essential python-dev python-smbus python-pip git -y
git clone https://github.com/adafruit/Adafruit_Python_CharLCD.git
cd Adafruit_Python_CharLCD
python setup.py install

#!/usr/bin/python
import math
import time

import Adafruit_CharLCD as LCD

# Raspberry Pi pin configuration:
lcd_rs = 23
lcd_en = 24
lcd_d4 = 17
lcd_d5 = 18
lcd_d6 = 27
lcd_d7 = 22
lcd_backlight = 25

# Define LCD column and row size for 16x2 LCD.
lcd_columns = 16
lcd_rows = 2

# Initialize the LCD using the pins above.
lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns, lcd_rows, lcd_backlight)

# Print a two line message
lcd.message('ABC\n226.5 MHz')

lcd.set_backlight(0)
time.sleep(1)
lcd.set_backlight(1)
time.sleep(1)
lcd.set_backlight(0)
time.sleep(1)
lcd.set_backlight(1)
time.sleep(1)