See the next page of this guide for info on some minor edits that are required to the code so that the CLUEs have unique names and can find each other.

Installing Project Code

To use with CircuitPython, you need to first install a few libraries, into the lib folder on your CIRCUITPY drive. Then you need to update code.py with the example script.

Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, open the directory CLUE_BLE_Morse_Code/ and then click on the directory that matches the version of CircuitPython you're using and copy the contents of that directory to your CIRCUITPY drive.

Your CIRCUITPY drive should now look similar to the following image:

CIRCUITPY
# SPDX-FileCopyrightText: 2020 Carter Nelson for Adafruit Industries
#
# SPDX-License-Identifier: MIT

import time
import displayio
import terminalio
from adafruit_clue import clue
from adafruit_display_text import label
import adafruit_imageload
from adafruit_ble import BLERadio
from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
from adafruit_ble.services.nordic import UARTService

# --| User Config |---------------------------------------------------
# Set to either A or B. The other CLUE should be set to opposite mode.
BLE_MODE = "A"
# --| User Config |---------------------------------------------------

BLE_MODE = BLE_MODE.upper().strip()
if BLE_MODE not in ("A", "B"):
    raise ValueError("BLE_MODE must be set to either A or B.")

WAIT_FOR_DOUBLE = 0.05
DEBOUNCE = 0.25

# Define Morse Code dictionary
morse_code = {
    ".-": "A",
    "-...": "B",
    "-.-.": "C",
    "-..": "D",
    ".": "E",
    "..-.": "F",
    "--.": "G",
    "....": "H",
    "..": "I",
    ".---": "J",
    "-.-": "K",
    ".-..": "L",
    "--": "M",
    "-.": "N",
    "---": "O",
    ".--.": "P",
    "--.-": "Q",
    ".-.": "R",
    "...": "S",
    "-": "T",
    "..-": "U",
    "...-": "V",
    ".--": "W",
    "-..-": "X",
    "-.--": "Y",
    "--..": "Z",
}

# BLE Radio Stuff
if BLE_MODE == "A":
    MY_NAME = "CENTRAL"
    FRIENDS_NAME = "PERIPHERAL"
else:
    MY_NAME = "PERIPHERAL"
    FRIENDS_NAME = "CENTRAL"
ble = BLERadio()
uart_service = UARTService()
advertisement = ProvideServicesAdvertisement(uart_service)
ble._adapter.name = MY_NAME  # pylint: disable=protected-access

# Display Stuff
display = clue.display
disp_group = displayio.Group()
display.root_group = disp_group

# Background BMP with the Morse Code cheat sheet
bmp, pal = adafruit_imageload.load(
    "morse_bg.bmp", bitmap=displayio.Bitmap, palette=displayio.Palette
)
disp_group.append(displayio.TileGrid(bmp, pixel_shader=pal))

# Incoming messages show up here
in_label = label.Label(terminalio.FONT, text="A" * 18, scale=2, color=0x000000)
in_label.anchor_point = (1.0, 0)
in_label.anchored_position = (235, 4)
disp_group.append(in_label)

# Outging messages show up here
out_label = label.Label(terminalio.FONT, text="B" * 18, scale=2, color=0x000000)
out_label.anchor_point = (1.0, 0)
out_label.anchored_position = (235, 180)
disp_group.append(out_label)

# Morse Code entry happens here
edit_label = label.Label(terminalio.FONT, text="----", scale=2, color=0x000000)
edit_label.anchor_point = (0.5, 0)
edit_label.anchored_position = (115, 212)
disp_group.append(edit_label)


def scan_and_connect():
    """
    Handles initial connection between the two CLUES.

    The CLUE set to BLE_MODE="A" will act as Central.
    The CLUE set to BLE_MODE="B" will act as Peripheral.

    Return is a UART object that can be used for read/write.
    """

    print("Connecting...")
    in_label.text = out_label.text = "Connecting..."

    if MY_NAME == "CENTRAL":
        keep_scanning = True
        print("Scanning...")

        while keep_scanning:
            for adv in ble.start_scan():
                if adv.complete_name == FRIENDS_NAME:
                    ble.stop_scan()
                    ble.connect(adv)
                    keep_scanning = False

        print("Connected. Done scanning.")
        return uart_service

    else:
        print("Advertising...")
        ble.start_advertising(advertisement)

        while not ble.connected:
            if ble.connected:
                break

        print("Connected. Stop advertising.")
        ble.stop_advertising()

        print("Connecting to Central UART service.")
        for connection in ble.connections:
            if UARTService not in connection:
                continue
            return connection[UARTService]

    return None


# --------------------------
# The main application loop
# --------------------------
while True:
    # Establish initial connection
    uart = scan_and_connect()

    print("Connected.")

    code = ""
    in_label.text = out_label.text = " " * 18
    edit_label.text = " " * 4
    done = False

    # Run the chat while connected
    while ble.connected:
        # Check for incoming message
        incoming_bytes = uart.in_waiting
        if incoming_bytes:
            bytes_in = uart.read(incoming_bytes)
            print("Received: ", bytes_in)
            in_label.text = in_label.text[incoming_bytes:] + bytes_in.decode()

        # DOT (or done)
        if clue.button_a:
            start = time.monotonic()
            while time.monotonic() - start < WAIT_FOR_DOUBLE:
                if clue.button_b:
                    done = True
            if not done and len(code) < 4:
                print(".", end="")
                code += "."
                edit_label.text = "{:4s}".format(code)
                time.sleep(DEBOUNCE)

        # DASH (or done)
        if clue.button_b:
            start = time.monotonic()
            while time.monotonic() - start < WAIT_FOR_DOUBLE:
                if clue.button_a:
                    done = True
            if not done and len(code) < 4:
                print("-", end="")
                code += "-"
                edit_label.text = "{:4s}".format(code)
                time.sleep(DEBOUNCE)

        # Turn Morse Code into letter and send
        if done:
            letter = morse_code.get(code, " ")
            print(" >", letter)
            out_label.text = out_label.text[1:] + letter
            uart.write(str.encode(letter))
            code = ""
            edit_label.text = " " * 4
            done = False
            time.sleep(DEBOUNCE)

    print("Disconnected.")

This guide was first published on Mar 04, 2020. It was last updated on May 26, 2024.

This page (Code) was last updated on May 26, 2024.

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