client.py

from time import sleep

from adafruit_ble import BLERadio
from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
from adafruit_ble.services.nordic import UARTService

from adafruit_bluefruit_connect.packet import Packet
from adafruit_bluefruit_connect.button_packet import ButtonPacket
from adafruit_bluefruit_connect.color_packet import ColorPacket

from neopixel import NeoPixel
from board import NEOPIXEL, SWITCH
from adafruit_debouncer import Debouncer
from digitalio import DigitalInOut, Direction, Pull
import adafruit_fancyled.adafruit_fancyled as fancy

pin = DigitalInOut(SWITCH)  # Set up built-in pushbutton switch
pin.direction = Direction.INPUT
pin.pull = Pull.UP
switch = Debouncer(pin)

pixels = NeoPixel(NEOPIXEL, 1)  # Set up built-in NeoPixel

AQUA = 0x00FFFF    # (0, 255, 255)
GREEN = 0x00FF00   # (0, 255, 0)
ORANGE = 0xFF8000  # (255, 128, 0)
RED = 0xFF0000     # (255, 0, 0)
BLUE = 0x0000FF    # (0, 0, 255)

gradients = {'Off': [(0.0, RED), (0.75, ORANGE)],
             'On':  [(0.0, GREEN), (1.0, AQUA)]}

palette = fancy.expand_gradient(gradients['Off'], 30)

gamma_levels = (0.25, 0.3, 0.15)
color_index = 1
fade_direction = 1

button_packet = ButtonPacket("1", True)  # Transmits pressed button 1

ble = BLERadio()

while True:
    uart_connection = None

    pixels[0] = BLUE  # Blue LED indicates disconnected status
    pixels.show()

    for adv in ble.start_scan(ProvideServicesAdvertisement):
        if UARTService in adv.services:
            uart_connection = ble.connect(adv)
            break

    # Stop scanning when connected.
    ble.stop_scan()

    while uart_connection and uart_connection.connected:
        uart_service = uart_connection[UARTService]
        switch.update()
        if switch.fell:  # Check for button press
            try:
                uart_service.write(button_packet.to_bytes())  # Transmit press
            except OSError:
                uart_connection = None
                continue
        # Check for LED status receipt
        if uart_service.in_waiting:
            packet = Packet.from_stream(uart_service)
            if isinstance(packet, ColorPacket):
                if fancy.CRGB(*packet.color).pack() == GREEN:  # Color match
                    # Green indicates on state
                    palette = fancy.expand_gradient(gradients['On'], 30)
                else:
                    # Otherwise red indicates off
                    palette = fancy.expand_gradient(gradients['Off'], 30)

        # NeoPixel color fading routing
        color = fancy.palette_lookup(palette, color_index / 29)
        color = fancy.gamma_adjust(color, brightness=gamma_levels)
        c = color.pack()
        pixels[0] = c
        pixels.show()
        if color_index == 0 or color_index == 28:
            fade_direction *= -1  # Change direction
        color_index += fade_direction

        sleep(0.02)