The server code requires the following libraries from the CircuitPython Bundle:
- adafruit_ble
- adafruit_bluefruit_connect
The code for this project needs extensive revision due to changes in CircuitPython. Sorry!
The latest version can be obtained from the Adafruit CircuitPython BLE repo.
Plug in one Feather nRF52840 to your computer via a known good USB data + power cable. The board should show up as a disk drive named CIRCUITPY. Use this guide to update CircuitPython - you will want the latest version 5.0 or above.
Download and copy the two aforementioned libraries to the lib folder on the Feather.
Here's the server code for the BLE peripheral. Click the download link and save to your computer. Then copy the server.py file to code.py on the Feather.
# SPDX-FileCopyrightText: 2019 Anne Barela for Adafruit Industries
#
# SPDX-License-Identifier: MIT
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 board import A0, D13
from analogio import AnalogIn
from digitalio import DigitalInOut, Direction
led = AnalogIn(A0) # Initialize blue LED light detector
solenoid = DigitalInOut(D13) # Initialize solenoid
solenoid.direction = Direction.OUTPUT
solenoid.value = False
ble = BLERadio()
uart_server = UARTService()
advertisement = ProvideServicesAdvertisement(uart_server)
while True:
ble.start_advertising(advertisement) # Advertise when not connected.
while not ble.connected:
pass
while ble.connected: # Connected
if uart_server.in_waiting: # Check BLE commands
packet = Packet.from_stream(uart_server)
if isinstance(packet, ButtonPacket):
if packet.button == '1' and packet.pressed:
solenoid.value = True # Activate solenoid for 1 second
sleep(1)
solenoid.value = False
led_intensity = led.value # Check blue LED detector intensity
led_on = led_intensity > 1000
# Color: red = off, green = on
color_packet = ColorPacket((255 * int(not led_on), 255 * led_on, 0))
try:
uart_server.write(color_packet.to_bytes()) # Transmit state color
except OSError:
pass
sleep(.2)
