Last Updated or created 2025-01-15
To display quotes, changing once per hour.
There is not much to be found for Waveshare 4.2 Epaper.
Except for an Arduino web example.
( see https://www.waveshare.com/wiki/E-Paper_ESP32_Driver_Board )
I reversed engineered the workings, and created a python upload script to push images.
Original workings are a mess.
Per 4 bit of color, high-low switched in a byte.
Black and red separated.
Using a till p encoding over curl commands.
My implementation uses a python script called as:
python3 epaper-pusher.py ~/Downloads/Untitled.png
http://10.1.0.99/EPDI_ 30 times something like http://10.1.0.99/ppppppppppppppppppppppppppppppppppppppppppppppppppppppaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbbbbbbbbbbppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppiodaLOAD_ http://10.1.0.99/NEXT_ 30 times something like http://10.1.0.99/pbcdefghijjjjjjffffffoooooooaaabbbbbbeeeedddppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppiodaLOAD_ http://10.1.0.99/SHOW_
NOTES: a = 0000 - - - p = 1111 = 15 30 lines with 1000 bytes ( ending with iodaLOAD_ ) black pixels first block 1 second block 0 red pixels first block 0 second block 1 white pixels first block 1 second block 1 PIXEL Example RBRB BWBW First block 1010 - letter K 0101 - Letter F - second nibble = white Second block 0101 - Letter F 1111 - Letter P - second nibble white
Code
from PIL import Image
import numpy
import requests
url="http://10.1.0.99/"
black_pixels = numpy.zeros((400,300))
red_pixels = numpy.zeros((400,300))
def classify_pixel_color(pixel):
"""
Classify a pixel as black, white, or red.
"""
r, g, b = pixel[:3] # Ignore alpha if present
# Define thresholds for classification
if r < 128 and g < 128 and b < 128:
return 'black'
elif r > 200 and g > 200 and b > 200:
return 'white'
elif r > 128 and g < 100 and b < 100:
return 'red'
else:
return None
def process_image(image_path):
"""
Process the image and classify its pixels into black, white, or red.
"""
image = Image.open(image_path)
image = image.convert("RGB") # Ensure the image is in RGB mode
width, height = image.size
pixel_data = image.load()
color_counts = {'black': 0, 'white': 0, 'red': 0}
for y in range (0, 299):
for x in range (0, 399):
black_pixels[x][y] = 0
red_pixels[x][y] = 0
for y in range(299):
for x in range(399):
color = classify_pixel_color(pixel_data[x, y])
if color:
color_counts[color] += 1
if color == 'black':
black_pixels[x][y] = 1;
if color == 'red':
red_pixels[x][y] = 1;
if color == 'white':
black_pixels[x][y] = 1;
red_pixels[x][y] = 1;
return color_counts, black_pixels, red_pixels
def number_to_letter(num):
"""
Translates a number from 0 to 15 into a corresponding letter (a-p).
Args:
num (int): The number to translate.
Returns:
str: The corresponding letter (a-p).
"""
if 0 <= num <= 15:
return chr(ord('a') + num)
else:
raise ValueError("Number must be between 0 and 15, inclusive.")
def print_array_in_chunks(array, chunk_size=1001):
current_chunk = ""
for item in array:
# Convert item to string and add to the current chunk
item_str = str(item)
if len(current_chunk) + len(item_str) + 1 > chunk_size:
# Print the current chunk and reset it
current_chunk += "iodaLOAD_"
try:
requests.get(url + current_chunk, verify=False)
if not response.content: # Equivalent to expecting an empty reply
pass
except requests.exceptions.RequestException as e:
# Catch any request-related errors
pass
current_chunk = item_str
else:
# Append the item to the current chunk
current_chunk += (item_str)
current_chunk += "iodaLOAD_"
# Print any remaining items in the chunk
if current_chunk:
try:
requests.get(url + current_chunk, verify=False)
if not response.content: # Equivalent to expecting an empty reply
pass
except requests.exceptions.RequestException as e:
# Catch any request-related errors
pass
def switch_in_pairs(arr):
# Loop through the array with a step of 2
for i in range(0, len(arr) - 1, 2):
# Swap values at index i and i+1
arr[i], arr[i + 1] = arr[i + 1], arr[i]
return arr
if __name__ == "__main__":
import sys
if len(sys.argv) < 2:
print("Usage: python3 script.py <image_path>")
sys.exit(1)
image_path = sys.argv[1]
try:
color_counts, black_pixels, red_pixels = process_image(image_path)
try:
requests.get(url + "EPDI_" , verify=False)
if not response.content: # Equivalent to expecting an empty reply
pass
except requests.exceptions.RequestException as e:
# Catch any request-related errors
pass
lines=[]
for y in range(300):
for x in range(0,399,4):
first = red_pixels[x][y]
second = red_pixels[x+1][y]
thirth = red_pixels[x+2][y]
fourth = red_pixels[x+3][y]
nibble = 0
if (first == 1):
nibble = nibble + 8
if (second == 1):
nibble = nibble + 4
if (thirth == 1):
nibble = nibble + 2
if (fourth == 1):
nibble = nibble + 1
lines.append(number_to_letter(nibble))
switched_array = switch_in_pairs(lines)
print_array_in_chunks(switched_array)
try:
requests.get(url + "NEXT_" , verify=False)
if not response.content: # Equivalent to expecting an empty reply
pass
except requests.exceptions.RequestException as e:
# Catch any request-related errors
pass
lines=[]
for y in range(300):
for x in range(0,399,4):
first = black_pixels[x][y]
second = black_pixels[x+1][y]
thirth = black_pixels[x+2][y]
fourth = black_pixels[x+3][y]
nibble = 0
if (first == 1):
nibble = nibble + 8
if (second == 1):
nibble = nibble + 4
if (thirth == 1):
nibble = nibble + 2
if (fourth == 1):
nibble = nibble + 1
lines.append(number_to_letter(nibble))
switched_array = switch_in_pairs(lines)
print_array_in_chunks(switched_array)
try:
requests.get(url + "SHOW_" , verify=False)
if not response.content: # Equivalent to expecting an empty reply
pass
except requests.exceptions.RequestException as e:
# Catch any request-related errors
pass
except Exception as e:
pass
