code-sd.py

import board
import struct
import time
import busio
import sdcardio
import storage

display = board.DISPLAY
display.auto_refresh = False

# Setup SD card and mount it to /sd directory

spi = busio.SPI(board.SD_SCK, MOSI=board.SD_MOSI, MISO=board.SD_MISO)
cs = board.SD_CS
sdcard = sdcardio.SDCard(spi, cs, baudrate=31_250_000)
vfs = storage.VfsFat(sdcard)
storage.mount(vfs, "/sd")

def send_chunks_to_display(file_path, width=320, rows = 24):
    
    chunk_size= 2 * width * rows # 2bytes per pixel - every chunk = row * number of rows to display at once
    chunk = bytearray(chunk_size)
    row_start = 0

    send = display.bus.send
    pack = struct.pack
    mw = memoryview

    send(42, pack(">hh", 0, width-1))
    
    with open(file_path, "rb") as f:
        read = f.readinto
        
        while True:
            n = read(chunk)
            if n == 0:
                break
            send(43, pack(">hh", row_start, row_start + rows))
            send(44, mw(chunk)[:n])
            row_start += rows

while True:
    # Bitmaps are in RGB 565 Swapped format
    # converter: https://lvgl.io/tools/imageconverter
    
    send_chunks_to_display("/sd/img1.bin")
    time.sleep(3)
    send_chunks_to_display("/sd/img2.bin")
    time.sleep(3)

code.py

import board
import struct
import time

display = board.DISPLAY
display.auto_refresh = False

def send_chunks_to_display(file_path, width=320, rows = 24):
    
    chunk_size= 2 * width * rows # 2bytes per pixel - every chunk = row * number of rows to display at once
    chunk = bytearray(chunk_size)
    row_start = 0

    send = display.bus.send
    pack = struct.pack
    mw = memoryview

    send(42, pack(">hh", 0, width-1))
    
    with open(file_path, "rb") as f:
        read = f.readinto
        
        while True:
            n = read(chunk)
            if n == 0:
                break
            send(43, pack(">hh", row_start, row_start + rows))
            send(44, mw(chunk)[:n])
            row_start += rows

while True:
    # Bitmaps are in RGB 565 Swapped format
    # converter: https://lvgl.io/tools/imageconverter
    
    send_chunks_to_display("/SLIDE/img1.bin")
    time.sleep(3)
    send_chunks_to_display("/SLIDE/img2.bin")
    time.sleep(3)