Raspberry Pi Course Code

blink.py

#!/usr/bin/python
import RPi.GPIO as GPIO
import time

led = 18  # GPIO18
delay = 1  # one second
GPIO.setwarnings(False)  # disable warnings
GPIO.setmode(GPIO.BCM)  # mode BCM or Board
GPIO.setup(led, GPIO.OUT)  # input or output
isRunning = True
while isRunning:
    try:
        GPIO.output(led, True)
        time.sleep(delay)
        GPIO.output(led, False)
        time.sleep(delay)
    except KeyboardInterrupt:
        isRunning = False
GPIO.cleanup()

DHT.py

import Adafruit_DHT
import time

isRunning = True
while isRunning:
    try:
        humidity, temperature = Adafruit_DHT.read_retry(Adafruit_DHT.DHT11, 4)
        if humidity is not None and temperature is not None:
            print('Temp={0:0.1f}*  Humidity={1:0.1f}%'.format(temperature, humidity))
        else:
            print('Failed to get reading. Try again!')
        time.sleep(1)
    except KeyboardInterrupt:
        isRunning = False

pwm.py

#!/usr/bin/python
import RPi.GPIO as GPIO

led = 18  # GPIO18
GPIO.setwarnings(False)  # disable warnings
GPIO.setmode(GPIO.BCM)  # mode BCM or Board
GPIO.setup(led, GPIO.OUT)  # input or output
pwm_led = GPIO.PWM(led, 500)
pwm_led.start(100)
isRunning = True
while isRunning:
    try:
        duty_s = raw_input("Enter Brightness (0 to 100): ")
        duty = int(duty_s)
        pwm_led.ChangeDutyCycle(duty)
    except KeyboardInterrupt:
        isRunning = False
GPIO.cleanup()

servomotor.py

from Tkinter import *
import RPi.GPIO as GPIO
import time


class App:
    def __init__(self, master):
        frame = Frame(master)
        GPIO.setmode(GPIO.BCM)
        GPIO.setup(18, GPIO.OUT)
        pwm = GPIO.PWM(18, 100)
        pwm.start(5)
        frame.pack()
        scale = Scale(frame, from_=0, to=180, orient=HORIZONTAL, command=self.update)
        scale.grid(row=0)

    def update(self, angle):
        duty = float(angle) / 10.0 + 2.5
        pwm.ChangeDutyCycle(duty)

    def __exit__(self, exc_type, exc_val, exc_tb):
        GPIO.cleanup()


root = Tk()
root.wm_title('Servo Control')
app = App(root)
root.geometry("200x50+0+0")
root.mainloop()

switch1.py

#!/usr/bin/python
import RPi.GPIO as GPIO
import time

switch = 18  # GPIO18
delay = 0.2  # 0.2 seconds
GPIO.setwarnings(False)  # disable warnings
GPIO.setmode(GPIO.BCM)  # mode BCM or Board
GPIO.setup(switch, GPIO.IN, pull_up_down=GPIO.PUD_UP)  # input or output
isRunning = True
while isRunning:
    try:
        input_state = GPIO.input(switch)
        if not input_state:
            print("Button Pressed")
        time.sleep(delay)
    except KeyboardInterrupt:
        isRunning = False
GPIO.cleanup()

switch2.py

#!/usr/bin/python
import RPi.GPIO as GPIO
import time

led = 18  # GPIO18
switch = 23
GPIO.setwarnings(False)  # disable warnings
GPIO.setmode(GPIO.BCM)  # mode BCM or Board
GPIO.setup(led, GPIO.OUT)  # input or output
GPIO.setup(switch, GPIO.IN, pull_up_down=GPIO.PUD_UP)
led_state = False
old_input_state = True
isRunning = True
while isRunning:
    try:
        new_input_state = GPIO.input(switch)
        if not new_input_state and old_input_state:
            led_state = not led_state
        old_input_state = new_input_state
        GPIO.output(led, led_state)
    except KeyboardInterrupt:
        isRunning = False
GPIO.cleanup()

ultrasound.py

import RPi.GPIO as GPIO
import time

TRIG = 23
ECHO = 24

GPIO.setmode(GPIO.BCM)

print "Distance Measurement In Progress"
GPIO.setup(TRIG, GPIO.OUT)
GPIO.setup(ECHO, GPIO.IN)

isRunning = True
while isRunning:
    try:
        GPIO.output(TRIG, False)
        print "Waiting For Sensor To Settle"
        time.sleep(2)
        GPIO.output(TRIG, True)
        time.sleep(0.00001)
        GPIO.output(TRIG, False)
        while GPIO.input(ECHO) == 0:
            pulse_start = time.time()
        while GPIO.input(ECHO) == 1:
            pulse_end = time.time()
        pulse_duration = pulse_end - pulse_start
        distance = pulse_duration * 17150
        distance = round(distance, 2)
        print "Distance:", distance, "cm"
    except KeyboardInterrupt:
        isRunning = False
GPIO.cleanup()