Use four GPIO buttons as forward/back/left/right controls for a robot:

 
from gpiozero import Robot, Button
from signal import pause

robot = Robot(left=(4, 14), right=(17, 18))

left = Button(26)
right = Button(16)
fw = Button(21)
bw = Button(20)

fw.when_pressed = robot.forward
fw.when_released = robot.stop

left.when_pressed = robot.left
left.when_released = robot.stop

right.when_pressed = robot.right
right.when_released = robot.stop

bw.when_pressed = robot.backward
bw.when_released = robot.stop

pause()

Make a robot drive forward when it detects motion:

 
from gpiozero import Robot, MotionSensor
from signal import pause

robot = Robot(left=(4, 14), right=(17, 18))
pir = MotionSensor(5)

pir.when_motion = robot.forward
pir.when_no_motion = robot.stop

pause()

Alternatively:

 
from gpiozero import Robot, MotionSensor
from gpiozero.tools import zip_values
from signal import pause

robot = Robot(left=(4, 14), right=(17, 18))
pir = MotionSensor(5)

robot.source = zip_values(pir, pir)

pause()

Continually print the value of a potentiometer (values between 0 and 1) connected to a MCP3008 analog to digital converter:

 
from gpiozero import MCP3008

pot = MCP3008(channel=0)

while True:
    print(pot.value)

Present the value of a potentiometer on an LED bar graph using PWM to represent states that won’t “fill” an LED:

 
from gpiozero import LEDBarGraph, MCP3008
from signal import pause

graph = LEDBarGraph(5, 6, 13, 19, 26, pwm=True)
pot = MCP3008(channel=0)

graph.source = pot

pause()

Wire a TMP36 temperature sensor to the first channel of an MCP3008 analog to digital converter:

 
from gpiozero import MCP3008
from time import sleep

def convert_temp(gen):
    for value in gen:
        yield (value * 3.3 - 0.5) * 100

adc = MCP3008(channel=0)

for temp in convert_temp(adc.values):
    print('The temperature is', temp, 'C')
    sleep(1)

Wire up three potentiometers (for red, green and blue) and use each of their values to make up the colour of the LED:

 
from gpiozero import RGBLED, MCP3008

led = RGBLED(red=2, green=3, blue=4)
red_pot = MCP3008(channel=0)
green_pot = MCP3008(channel=1)
blue_pot = MCP3008(channel=2)

while True:
    led.red = red_pot.value
    led.green = green_pot.value
    led.blue = blue_pot.value

Alternatively, the following example is identical, but uses the source property rather than a while loop:

 
from gpiozero import RGBLED, MCP3008
from gpiozero.tools import zip_values
from signal import pause

led = RGBLED(2, 3, 4)
red_pot = MCP3008(0)
green_pot = MCP3008(1)
blue_pot = MCP3008(2)

led.source = zip_values(red_pot, green_pot, blue_pot)

pause()

If you have a pet (e.g. a tortoise) which requires a heat lamp to be switched on for a certain amount of time each day, you can use an Energenie Pi-mote to remotely control the lamp, and the TimeOfDay class to control the timing:

 
from gpiozero import Energenie, TimeOfDay
from datetime import time
from signal import pause

lamp = Energenie(1)
daytime = TimeOfDay(time(8), time(20))

lamp.source = daytime
lamp.source_delay = 60

pause()

You can use a pair of green and red LEDs to indicate whether or not your internet connection is working. Simply use the PingServer class to identify whether a ping to google.com is successful. If successful, the green LED is lit, and if not, the red LED is lit:

 
from gpiozero import LED, PingServer
from gpiozero.tools import negated
from signal import pause

green = LED(17)
red = LED(18)

google = PingServer('google.com')

green.source = google
green.source_delay = 60
red.source = negated(green)

pause()

You can read the Raspberry Pi’s own CPU temperature using the built-in CPUTemperature class, and display this on a “bar graph” of LEDs:

 
from gpiozero import LEDBarGraph, CPUTemperature
from signal import pause

cpu = CPUTemperature(min_temp=50, max_temp=90)
leds = LEDBarGraph(2, 3, 4, 5, 6, 7, 8, pwm=True)

leds.source = cpu

pause()

You can iterate over the LEDs in a LEDBoard object one-by-one:

 
from gpiozero import LEDBoard
from time import sleep

leds = LEDBoard(5, 6, 13, 19, 26)

for led in leds:
    led.on()
    sleep(1)
    led.off()

LEDBoard also supports indexing. This means you can access the individual LED objects using leds[i] where i is an integer from 0 up to (not including) the number of LEDs:

 
from gpiozero import LEDBoard
from time import sleep

leds = LEDBoard(2, 3, 4, 5, 6, 7, 8, 9)

leds[0].on()  # first led on
sleep(1)
leds[7].on()  # last led on
sleep(1)
leds[-1].off()  # last led off
sleep(1)

This also means you can use slicing to access a subset of the LEDs:

 
from gpiozero import LEDBoard
from time import sleep

leds = LEDBoard(2, 3, 4, 5, 6, 7, 8, 9)

for led in leds[3:]:  # leds 3 and onward
    led.on()
sleep(1)
leds.off()

for led in leds[:2]:  # leds 0 and 1
    led.on()
sleep(1)
leds.off()

for led in leds[::2]:  # even leds (0, 2, 4...)
    led.on()
sleep(1)
leds.off()

for led in leds[1::2]:  # odd leds (1, 3, 5...)
    led.on()
sleep(1)
leds.off()

LEDBoard objects can have their LED objects named upon construction. This means the individual LEDs can be accessed by their name:

 
from gpiozero import LEDBoard
from time import sleep

leds = LEDBoard(red=2, green=3, blue=4)

leds.red.on()
sleep(1)
leds.green.on()
sleep(1)
leds.blue.on()
sleep(1)

LEDBoard objects can also be nested within other LEDBoard objects:

 
from gpiozero import LEDBoard
from time import sleep

leds = LEDBoard(red=LEDBoard(top=2, bottom=3), green=LEDBoard(top=4, bottom=5))

leds.red.on() ## both reds on
sleep(1)
leds.green.on()  # both greens on
sleep(1)
leds.off()  # all off
sleep(1)
leds.red.top.on()  # top red on
sleep(1)
leds.green.bottom.on()  # bottom green on
sleep(1)

Using a number of green-red LED pairs, you can show the status of who’s home, according to which IP addresses you can ping successfully. Note that this assumes each person’s mobile phone has a reserved IP address on the home router.

 
from gpiozero import PingServer, LEDBoard
from gpiozero.tools import negated
from signal import pause

status = LEDBoard(
    mum=LEDBoard(red=14, green=15),
    dad=LEDBoard(red=17, green=18),
    alice=LEDBoard(red=21, green=22)
)

statuses = {
    PingServer('192.168.1.5'): status.mum,
    PingServer('192.168.1.6'): status.dad,
    PingServer('192.168.1.7'): status.alice,
}

for server, leds in statuses.items():
    leds.green.source = server
    leds.green.source_delay = 60
    leds.red.source = negated(leds.green)

pause()

Button controlled robot - GPIO library

Motion sensor robot - GPIO library

Potentiometer - GPIO library

Measure temperature with an ADC - GPIO library

Full color LED controlled by 3 potentiometers - GPIO library

Timed heat lamp - GPIO library

Internet connection status indicator - GPIO library

CPU Temperature Bar Graph - GPIO library

LEDBoard - GPIO library

Who’s home indicator - GPIO library