At this point, you should have just about everything already set up.
Besides the display, audio, and fan, this board has quite a few other useful features on it that can be controlled through Python. We'll go through those and how to control them in Python.
The 5-way Joystick and button just use simple digitalio and each uses a separate GPIO, so they're really simple to control. Here's a little script that will setup the GPIOs, Create Internal Pullups, and then print out the value to the terminal.
import time
import board
from digitalio import DigitalInOut, Direction, Pull
BUTTON_PIN = board.D17
JOYDOWN_PIN = board.D27
JOYLEFT_PIN = board.D22
JOYUP_PIN = board.D23
JOYRIGHT_PIN = board.D24
JOYSELECT_PIN = board.D16
buttons = [BUTTON_PIN, JOYUP_PIN, JOYDOWN_PIN,
JOYLEFT_PIN, JOYRIGHT_PIN, JOYSELECT_PIN]
for i,pin in enumerate(buttons):
buttons[i] = DigitalInOut(pin)
buttons[i].direction = Direction.INPUT
buttons[i].pull = Pull.UP
button, joyup, joydown, joyleft, joyright, joyselect = buttons
while True:
if not button.value:
print("Button pressed")
if not joyup.value:
print("Joystick up")
if not joydown.value:
print("Joystick down")
if not joyleft.value:
print("Joystick left")
if not joyright.value:
print("Joystick right")
if not joyselect.value:
print("Joystick select")
time.sleep(0.01)
Go ahead and save the above code onto your Pi as button_test.py and run it with the following command:
python button_test.py
Now try moving the joystick and press the button and you should see it print out what you're pressing.
The 3 DotStar LEDS can be controlled with the DotStar CircuitPython Library. Here's a little script that will setup the DotStar LEDs and then color cycle them.
import time
import board
import adafruit_dotstar
DOTSTAR_DATA = board.D5
DOTSTAR_CLOCK = board.D6
dots = adafruit_dotstar.DotStar(DOTSTAR_CLOCK, DOTSTAR_DATA, 3, brightness=0.2)
def wheel(pos):
# Input a value 0 to 255 to get a color value.
# The colours are a transition r - g - b - back to r.
if pos < 0 or pos > 255:
return (0, 0, 0)
if pos < 85:
return (255 - pos * 3, pos * 3, 0)
if pos < 170:
pos -= 85
return (0, 255 - pos * 3, pos * 3)
pos -= 170
return (pos * 3, 0, 255 - pos * 3)
while True:
for j in range(255):
for i in range(3):
rc_index = (i * 256 // 3) + j * 5
dots[i] = wheel(rc_index & 255)
dots.show()
time.sleep(0.01)
Go ahead and save the above code onto your Pi as dotstar_test.py and run it with the following command:
python dotstar_test.py
The DotStar LEDs should start color-cycling in a rainbow.
Parts
For this script, we'll just need one part that isn't included with the BrainCraft HAT:
Wiring
Code
import time
import board
import pulseio
from adafruit_motor import servo
SERVO_PIN = board.D12
pwm = pulseio.PWMOut(SERVO_PIN, frequency=50)
servo = servo.Servo(pwm, min_pulse=750, max_pulse=2250)
while True:
for angle in range(0, 180, 5): # 0 - 180 degrees, 5 degrees at a time.
servo.angle = angle
time.sleep(0.05)
for angle in range(180, 0, -5): # 180 - 0 degrees, 5 degrees at a time.
servo.angle = angle
time.sleep(0.05)
Go ahead and save the above code onto your Pi as servo_test.py and run it with the following command:
python servo_test.py
The servo should start sweeping back and forth in 5 degree increments.
For the Stemma QT port, you can use any of our 50+ sensors, but we're going to use a script that demonstrates using the BMP280 because it's so simple.
Parts
For this script, we'll just need a BMP280 and a Stemma QT cable:
Wiring
- Connect one side of the Stemma QT cable to either port on the BMP280
- Connect the other side to the Stemma QT port on the BrainCraft HAT
Code
# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT
"""Simpletest Example that shows how to get temperature,
pressure, and altitude readings from a BMP280"""
import time
import board
# import digitalio # For use with SPI
import adafruit_bmp280
# Create sensor object, communicating over the board's default I2C bus
i2c = board.I2C() # uses board.SCL and board.SDA
# i2c = board.STEMMA_I2C() # For using the built-in STEMMA QT connector on a microcontroller
bmp280 = adafruit_bmp280.Adafruit_BMP280_I2C(i2c)
# OR Create sensor object, communicating over the board's default SPI bus
# spi = board.SPI()
# bmp_cs = digitalio.DigitalInOut(board.D10)
# bmp280 = adafruit_bmp280.Adafruit_BMP280_SPI(spi, bmp_cs)
# change this to match the location's pressure (hPa) at sea level
bmp280.sea_level_pressure = 1013.25
while True:
print("\nTemperature: %0.1f C" % bmp280.temperature)
print("Pressure: %0.1f hPa" % bmp280.pressure)
print("Altitude = %0.2f meters" % bmp280.altitude)
time.sleep(2)
Go ahead and save the above code onto your Pi as bmp280_simpletest.py and run it with the following command:
python bmp280_simpletest.py
The terminal should start printing out the detected measurements.
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