The first step with any new hardware is the 'hello world' of electronics - blinking an LED. This is very easy with CircuitPython and Orange Pi. We'll extend the example to also show how to wire up a button/switch.
Any old LED will work just fine as long as its not an IR LED (you can't see those) and a 470 to 2.2K resistor
Some tactile buttons or switches
We recommend using a breadboard and some female-male wires.
You can use a Cobbler to make this a little easier, the pins will be labeled according to Raspberry Pi names so just check the Orange Pi name!
Wiring
Connect the Orange Pi Ground pin to the blue ground rail on the breadboard.
- Connect one side of the tactile switch to Orange Pi GPIO PA6
- Connect a ~10K pull up resistor from PA6 to 3.3V
- Connect the other side of the tactile switch to the ground rail
- Connect the longer/positive pin of the LED to Orange Pi GPIO PD14
- Connect the shorter/negative pin of the LED to a 470ohm to 2.2K resistor, the other side of the resistor goes to ground rail
There's no Orange Pi PC Fritzing object, so we sub'd a Raspberry Pi in
Double-check you have the right wires connected to the right location, it can be tough to keep track of Pi pins as there are forty of them!
No additional libraries are needed so we can go straight on to the example code
However, we recommend running a pip3 update!
pip3 install --upgrade adafruit_blinka
Blinky Time!
The finish line is right up ahead, lets start with an example that blinks the LED on and off once a second (half a second on, half a second off):
import time
import board
import digitalio
print("hello blinky!")
led = digitalio.DigitalInOut(board.PD14)
led.direction = digitalio.Direction.OUTPUT
while True:
led.value = True
time.sleep(0.5)
led.value = False
time.sleep(0.5)
Verify the LED is blinking. If not, check that it's wired to GPIO PD14, the resistor is installed correctly, and you have a Ground wire to the Orange Pi.
Type Control-C to quit
Button It Up
Now that you have the LED working, lets add code so the LED turns on whenever the button is pressed
import time
import board
import digitalio
print("press the button!")
led = digitalio.DigitalInOut(board.PD14)
led.direction = digitalio.Direction.OUTPUT
button = digitalio.DigitalInOut(board.PA6)
button.direction = digitalio.Direction.INPUT
# use an external pullup since we don't have internal PU's
#button.pull = digitalio.Pull.UP
while True:
led.value = not button.value # light when button is pressed!
Press the button - see that the LED lights up!
Type Control-C to quit
