Once you've finished setting up your Adafruit CLUE with CircuitPython, you can access the code and necessary libraries by downloading the Project Bundle.
To do this, click on the Download Project Bundle button in the window below. It will download as a zipped folder.
# SPDX-FileCopyrightText: 2021 Jeff Epler for Adafruit Industries
#
# SPDX-License-Identifier: MIT
import os
import board
import keypad
import ulab.numpy as np
from adafruit_ble import BLERadio
from adafruit_ble.advertising import Advertisement
from thermalprinter import CatPrinter
from seekablebitmap import imageopen
ble = BLERadio() # pylint: disable=no-member
buttons = keypad.Keys([board.BUTTON_A, board.BUTTON_B], value_when_pressed=False)
def wait_for_press(kbd):
"""
Wait for a keypress and return the event
"""
while True:
event = kbd.events.get()
if event and event.pressed:
return event
def show(s):
"""
Display a message on the screen
"""
board.DISPLAY.auto_refresh = False
print("\n" * 24)
print(s)
board.DISPLAY.auto_refresh = True
def show_error(s):
"""
Display a message on the screen and wait for a button press
"""
show(s + "\nPress a button to continue")
wait_for_press(buttons)
def find_cat_printer(radio):
"""
Connect to the cat printer device using BLE
"""
while True:
show("Scanning for GB02 device...")
for adv in radio.start_scan(Advertisement):
complete_name = getattr(adv, "complete_name")
if complete_name is not None:
print(f"Saw {complete_name}")
if complete_name == "GB02":
radio.stop_scan()
return radio.connect(adv, timeout=10)[CatPrinter]
image_files = [
i
for i in os.listdir("/")
if i.lower().endswith(".pbm") or i.lower().endswith(".bmp")
]
image_files.sort(key=lambda filename: filename.lower())
def select_image():
i = 0
while True:
show(
f"Select image file\nA: next image\nB: print this image\n\n{image_files[i]}"
)
event = wait_for_press(buttons)
if event.key_number == 0: # button "A"
i = (i + 1) % len(image_files)
if event.key_number == 1: # button "B"
return image_files[i]
printer = find_cat_printer(ble)
def main():
try:
filename = select_image()
show(f"Loading {filename}")
image = imageopen(filename)
if image.width != 384:
raise ValueError("Invalid image. Must be 384 pixels wide")
if image.bits_per_pixel != 1:
raise ValueError("Invalid image. Must be 1 bit per pixel (black & white)")
invert_image = image.palette and image.palette[0] == 0
show(f"Printing {filename}")
for i in range(image.height):
row_data = image.get_row(i)
if invert_image:
row_data = ~np.frombuffer(row_data, dtype=np.uint8)
printer.print_bitmap_row(row_data)
# Print blank lines until the paper can be torn off
for i in range(80):
printer.print_bitmap_row(b"\0" * 48)
except Exception as e: # pylint: disable=broad-except
show_error(str(e))
image_files.remove(filename)
while True:
main()
After downloading the Project Bundle, plug your Adafruit CLUE into the computer's USB port. You should see a new flash drive appear in the computer's File Explorer or Finder (depending on your operating system) called CIRCUITPY. Unzip the folder and copy the following items to the CLUE's CIRCUITPY drive.
Several sample images are included, continue on to "Using The Code" to print them. To prepare your own images, visit "Creating Images".
Page last edited January 22, 2025
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