First, the code makes all the required imports.

# General imports
import time
import random
import board
import digitalio
import neopixel

# HID imports
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS

# BLE imports
import adafruit_ble
from adafruit_ble.advertising import Advertisement
from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
from adafruit_ble.services.standard.hid import HIDService
from adafruit_ble.services.standard.device_info import DeviceInfoService

try:
    from audiocore import WaveFile
except ImportError:
    from audioio import WaveFile

try:
    from audioio import AudioOut
except ImportError:
    try:
        from audiopwmio import PWMAudioOut as AudioOut
    except ImportError:
        pass  # not always supported by every board!

Then, it sets up all the speaker that will be used to play a sound when a contestant buzzes in.

# Enable the speaker
spkrenable = digitalio.DigitalInOut(board.SPEAKER_ENABLE)
spkrenable.direction = digitalio.Direction.OUTPUT
spkrenable.value = True

Next, all the buttons are defined and a list is created to make determining which button is pressed a bit more elegant.

# Make the input buttons
btn1 = digitalio.DigitalInOut(board.D10)  # Marked A3
btn1.direction = digitalio.Direction.INPUT
btn1.pull = digitalio.Pull.UP

btn2 = digitalio.DigitalInOut(board.D9)  # Marked A2
btn2.direction = digitalio.Direction.INPUT
btn2.pull = digitalio.Pull.UP

btn3 = digitalio.DigitalInOut(board.D3)  # Marked SCL A4
btn3.direction = digitalio.Direction.INPUT
btn3.pull = digitalio.Pull.UP

central = digitalio.DigitalInOut(board.D0)  # Marked RX A6
central.direction = digitalio.Direction.INPUT
central.pull = digitalio.Pull.UP

led = digitalio.DigitalInOut(board.D2)  # Marked SDA A5
led.switch_to_output()
led.value = False

buttons = [btn1, btn2, btn3]
upper = len(buttons) - 1

Bluetooth is now set up, and the NeoPixels are enabled.

ble_enabled = digitalio.DigitalInOut(board.SLIDE_SWITCH)
ble_enabled.direction = digitalio.Direction.INPUT
ble_enabled.pull = digitalio.Pull.UP

pixels = neopixel.NeoPixel(board.NEOPIXEL, 10, brightness=0.5)
# Use default HID descriptor
hid = HIDService()
device_info = DeviceInfoService(
    software_revision=adafruit_ble.__version__, manufacturer="Adafruit Industries"
)
advertisement = ProvideServicesAdvertisement(hid)
advertisement.appearance = 961
scan_response = Advertisement()

ble = adafruit_ble.BLERadio()
if ble.connected:
    for c in ble.connections:
        c.disconnect()

if ble_enabled.value:
    print("advertising")
    ble.start_advertising(advertisement, scan_response)

k = Keyboard(hid.devices)
kl = KeyboardLayoutUS(k)

After that, the audio file is loaded.

wave_file = open("jeopardy.wav", "rb")
wave = WaveFile(wave_file)
audio = AudioOut(board.SPEAKER)

Now, the code enters the main loop. The first section of it connects to Bluetooth, if Bluetooth is enabled with the slide switch. When it connects, it flashes the LED on the central button to notify the user that it is connected.

while True:
    if ble_enabled.value:
        while not ble.connected:
            pass
        if ble.connected:
            print("Connected")
            led.value = True
            time.sleep(0.1)
            led.value = False
            time.sleep(0.1)
            led.value = True
            time.sleep(0.1)
            led.value = False

If it is connected, or if Bluetooth is disabled, the code now enters the section of the loop where it can poll the buttons to see which is pressed. It waits for a press from the central button, and if there is one, it turns that LED on and waits for the contestants to buzz in and only moves on to the next section when one has.

while ble.connected or not ble_enabled.value:
    if not central.value:
        led.value = True
        print("Running")
        while True:
            i = random.randint(0, upper)
            if not buttons[i].value:
                break

Then, the code will play the sound and set the NeoPixels to the color of the button that was pressed first. If BLE is enabled, it will send a string to the keyboard with the name of the button that got pressed.

After this, it waits for the central button to be pressed.

audio.play(wave)
if i == 0:
	print("Button 1")
	pixels.fill((0, 0, 255))
	if ble_enabled.value:
		kl.write("Button 1")
elif i == 1:
	print("Button 2")
	pixels.fill((0, 255, 0))
	if ble_enabled.value:
		kl.write("Button 2")
elif i == 2:
	print("Button 3")
	pixels.fill((255, 255, 255))
	if ble_enabled.value:
		kl.write("Button 3")

if not ble_enabled.value:
	print(
		"BLE HID has been disabled, slide the slide switch to the left to re-enable"
	)

print("Finished")
led.value = False

while central.value:
	pass

Now that the central button has been pressed, the code resets and goes over the inner loop again.

print("reset")
pixels.fill((0, 0, 0))
led.value = True
time.sleep(0.5)
led.value = False
print("Ready")

This section checks to see if BLE has been disconnected and breaks out of the loop if it has.

⠀⠀⠀if ble_enabled.value:
		if not ble.connected:
			break
else:
	continue
break

This guide was first published on Jun 22, 2021. It was last updated on 2021-06-22 16:57:35 -0400.

This page (Code Run-Through) was last updated on Sep 25, 2021.

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