1. Controlling LED with PWM
# A6 anode+ long lead
# A4 cathode- short lead
# B6 to B12 Resistor
# Brown-Red-Red 1.2KOhm
# C4 to GND
# B12 to GPIO 12 .
Copyright (c) 2017 Dr. E. Horvath

2. Controlling LED with PWM
import RPi.GPIO as GPIO
from time import sleep
def main():
GPIO.setmode(GPIO.BCM)
GPIO.setup(12, GPIO.OUT)
pwm_green = GPIO.PWM(12, 100) # GPIO=12 period=1/100Hz
pwm_green.start(0)
try:
while True:
for value in range(0, 101, 5):
pwm_green.ChangeDutyCycle(value)
sleep(0.3)
Copyright (c) 2017 Dr. E. Horvath

3. Controlling LED with PWM
for value in range(100, -1, -5):
pwm_green.ChangeDutyCycle(vakye)
sleep(0.3)
except KeyboardInterrupt:
print("Exiting")
finally:
pwm_green.stop()
GPIO.cleanup()
main() .
Copyright (c) 2017 Dr. E. Horvath

4. Copyright (c) 2017 Dr. E. Horvath
LED and Button Circuit
Copyright (c) 2017 Dr. E. Horvath

5. Handling Button Presses
# Button same side of button, across the divider of the board
# Button F25
# Button E25
# G21 to G27 10KOhm
# D27 to GND (Pin 39)
# H21 to GPIO 4
# Brown-Black-Orange 10KOhm resisto
Copyright (c) 2017 Dr. E. Horvath

6. Handling Button Presses
# Button same side of button, across the divider of the board
# Button F25
# Button E25
# G21 to G27 10KOhm
# D27 to GND (Pin 39)
# H21 to GPIO 4
# Brown-Black-Orange 10KOhm resistor
# It is very important to use a large resistance, since a low resistance will fry your Pi.
Copyright (c) 2017 Dr. E. Horvath

7. Handling Button Presses
def main():
GPIO.setmode(GPIO.BCM)
button_pin = 4
GPIO.setup(button_pin, GPIO.IN, pull_up_down=GPIO.PUD_UP)
# The GPIO is pulled high by default. The other side of the button is
# connected to GND, when the button is pressed, it is pulled down to
# ground.
Copyright (c) 2017 Dr. E. Horvath

8. Handling Button Presses
try:
while True:
value = GPIO.input(button_pin)
print("value " + str(value))
if value == 0:
print("Button pressed")
sleep(0.05)
except KeyboardInterrupt:
print("Exiting")
finally:
p.stop()
GPIO.cleanup()
main()
Copyright (c) 2017 Dr. E. Horvath

9. Copyright (c) 2017 Dr. E. Horvath
Speaker Leaf
#Used to play low level sounds.
# Red-Red-Brown 220 Ohm
# Speaker leaf s+ to F15
# Speaker leaf s- to F17
# G15 to G17 to 220Ohm
# H10 to GPIO pin 18
# I17 to GND pint 39
Copyright (c) 2017 Dr. E. Horvath

10. Copyright (c) 2017 Dr. E. Horvath
Speaker Leaf
import RPi.GPIO as GPIO
from time import sleep
def playsound():
print("Setup pins")
GPIO.setmode(GPIO.BCM)
pwm_pin = 18
GPIO.setup(pwm_pin,GPIO.OUT)
pwm_sound = GPIO.PWM(pwm_pin, 1000)
for j in range(0,len(melody)):
melody[j] = j*10
note_durations = [0.3] * len(melody)
Copyright (c) 2017 Dr. E. Horvath

11. Copyright (c) 2017 Dr. E. Horvath
Speaker Leaf
melody = [200,200,200,0,200,200,200,0,200,320,200,360,300]
note_durations = [0.3] * len(melody)
print("Trying to play")
try:
for i in range(0,len(melody)):
f = melody[i] # time between the pulses
print(str(f))
if f != 0:
pwm_sound = GPIO.PWM(pwm_pin, f)
pwm_sound.start(0.6)
Copyright (c) 2017 Dr. E. Horvath

12. Copyright (c) 2017 Dr. E. Horvath
Speaker Leaf
sleep(note_durations[i])
except KeyboardInterrupt:
print("Exiting...")
finally:
print("Cleanup")
GPIO.cleanup()
sleep(0.5)
print("Done")
playsound()
Copyright (c) 2017 Dr. E. Horvath