Add bitmap example

Author: jepler

docs/examples.rst

@@ -51,8 +51,8 @@ Preview images on LCD, bypassing displayio for slightly higher framerate
 Image-saving tests
 ------------------
 
-Kaluga 1.3 with ili9341, internal flash
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Kaluga 1.3 with ili9341, internal flash, JPEG
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Preview images on LCD t hen save JPEG images to internal flash on Kaluga 1.3.  Requires the second snippet of
 code to be saved as ``boot.py``.
@@ -67,15 +67,25 @@ code to be saved as ``boot.py``.
     :caption: ov2640_jpeg_kaluga1_3_boot.py
     :linenos:
 
-Kaluga 1.3 with ili9341, external SD card
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Kaluga 1.3 with ili9341, external SD card, JPEG
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Preview images on LCD then save JPEG images to SD on Kaluga 1.3 fitted with an ili9341 display.
 
 .. literalinclude:: ../examples/ov2640_jpeg_sd_kaluga1_3.py
     :caption: ov2640_jpeg_sd_kaluga1_3.py
     :linenos:
 
+Kaluga 1.3 with ili9341, external SD card, BMP
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Preview images on LCD then save BMP images to SD on Kaluga 1.3 fitted with an ili9341 display.
+
+.. literalinclude:: ../examples/ov2640_bmp_sd_kaluga1_3.py
+    :caption: ov2640_bmp_sd_kaluga1_3.py
+    :linenos:
+
+
 Kaluga 1.3 with Adafruit IO
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

examples/ov2640_bmp_sd_kaluga1_3.py

@@ -0,0 +1,220 @@
+# SPDX-FileCopyrightText: 2017 Scott Shawcroft, written for Adafruit Industries
+# SPDX-FileCopyrightText: Copyright (c) 2021 Jeff Epler for Adafruit Industries
+#
+# SPDX-License-Identifier: Unlicense
+
+"""
+The Kaluga development kit comes in two versions (v1.2 and v1.3); this demo is
+tested on v1.3.
+
+The audio board must be mounted between the Kaluga and the LCD, it provides the
+I2C pull-ups(!)
+
+The v1.3 development kit's LCD can have one of two chips, the ili9341 or
+st7789.  Furthermore, there are at least 2 ILI9341 variants, one of which needs
+rotation=90!  This demo is for the ili9341.  If the display is garbled, try adding
+rotation=90, or try modifying it to use ST7799.
+
+This example also requires an SD card breakout wired as follows:
+ * IO18: SD Clock Input
+ * IO17: SD Serial Output (MISO)
+ * IO14: SD Serial Input (MOSI)
+ * IO12: SD Chip Select
+
+Insert a CircuitPython-compatible SD card before powering on the Kaluga.
+Press the "Record" button on the audio daughterboard to take a photo in BMP format.
+"""
+
+import os
+import struct
+import time
+import binascii
+import ulab.numpy as np
+
+import analogio
+import board
+import busio
+import displayio
+import sdcardio
+import storage
+import ssl
+from adafruit_ili9341 import ILI9341
+import adafruit_ov2640
+
+# Nominal voltages of several of the buttons on the audio daughterboard
+V_MODE = 1.98
+V_RECORD = 2.41
+
+a = analogio.AnalogIn(board.IO6)
+
+# Release any resources currently in use for the displays
+displayio.release_displays()
+
+spi = busio.SPI(MOSI=board.LCD_MOSI, clock=board.LCD_CLK)
+display_bus = displayio.FourWire(
+    spi,
+    command=board.LCD_D_C,
+    chip_select=board.LCD_CS,
+    reset=board.LCD_RST,
+    baudrate=80_000_000,
+)
+_INIT_SEQUENCE = (
+    b"\x01\x80\x80"  # Software reset then delay 0x80 (128ms)
+    b"\xEF\x03\x03\x80\x02"
+    b"\xCF\x03\x00\xC1\x30"
+    b"\xED\x04\x64\x03\x12\x81"
+    b"\xE8\x03\x85\x00\x78"
+    b"\xCB\x05\x39\x2C\x00\x34\x02"
+    b"\xF7\x01\x20"
+    b"\xEA\x02\x00\x00"
+    b"\xc0\x01\x23"  # Power control VRH[5:0]
+    b"\xc1\x01\x10"  # Power control SAP[2:0];BT[3:0]
+    b"\xc5\x02\x3e\x28"  # VCM control
+    b"\xc7\x01\x86"  # VCM control2
+    b"\x36\x01\x90"  # Memory Access Control
+    b"\x37\x01\x00"  # Vertical scroll zero
+    b"\x3a\x01\x55"  # COLMOD: Pixel Format Set
+    b"\xb1\x02\x00\x18"  # Frame Rate Control (In Normal Mode/Full Colors)
+    b"\xb6\x03\x08\x82\x27"  # Display Function Control
+    b"\xF2\x01\x00"  # 3Gamma Function Disable
+    b"\x26\x01\x01"  # Gamma curve selected
+    b"\xe0\x0f\x0F\x31\x2B\x0C\x0E\x08\x4E\xF1\x37\x07\x10\x03\x0E\x09\x00"  # Set Gamma
+    b"\xe1\x0f\x00\x0E\x14\x03\x11\x07\x31\xC1\x48\x08\x0F\x0C\x31\x36\x0F"  # Set Gamma
+    b"\x11\x80\x78"  # Exit Sleep then delay 0x78 (120ms)
+    b"\x29\x80\x78"  # Display on then delay 0x78 (120ms)
+)
+
+display = displayio.Display(
+    display_bus, _INIT_SEQUENCE, width=320, height=240, auto_refresh=False
+)
+
+bus = busio.I2C(scl=board.CAMERA_SIOC, sda=board.CAMERA_SIOD)
+cam = adafruit_ov2640.OV2640(
+    bus,
+    data_pins=board.CAMERA_DATA,
+    clock=board.CAMERA_PCLK,
+    vsync=board.CAMERA_VSYNC,
+    href=board.CAMERA_HREF,
+    mclk=board.CAMERA_XCLK,
+    mclk_frequency=20_000_000,
+    size=adafruit_ov2640.OV2640_SIZE_QVGA,
+)
+
+cam.flip_x = False
+cam.flip_y = False
+cam.test_pattern = False
+
+g = displayio.Group(scale=1)
+bitmap = displayio.Bitmap(320, 240, 65536)
+tg = displayio.TileGrid(
+    bitmap,
+    pixel_shader=displayio.ColorConverter(
+        input_colorspace=displayio.Colorspace.RGB565_SWAPPED
+    ),
+)
+g.append(tg)
+display.show(g)
+
+
+sd_spi = busio.SPI(clock=board.IO18, MOSI=board.IO14, MISO=board.IO17)
+sd_cs = board.IO12
+sdcard = sdcardio.SDCard(sd_spi, sd_cs)
+vfs = storage.VfsFat(sdcard)
+storage.mount(vfs, "/sd")
+
+
+def exists(filename):
+    try:
+        os.stat(filename)
+        return True
+    except OSError as e:
+        return False
+
+
+_image_counter = 0
+
+
+def open_next_image(extension="jpg"):
+    global _image_counter
+    while True:
+        filename = f"/sd/img{_image_counter:04d}.{extension}"
+        _image_counter += 1
+        if exists(filename):
+            continue
+        print("#", filename)
+        return open(filename, "wb")
+
+
+### These routines are for writing BMP files in the RGB565 or BGR565 formats.
+_BI_BITFIELDS = 3
+
+_bitmask_rgb565 = (0xF800, 0x7E0, 0x1F)
+_bitmask_bgr565 = (0x1F, 0x7E0, 0xF800)
+
+
+def write_header(output_file, width, height, masks):
+    def put_word(value):
+        output_file.write(struct.pack("<H", value))
+
+    def put_dword(value):
+        output_file.write(struct.pack("<I", value))
+
+    def put_long(value):
+        output_file.write(struct.pack("<i", value))
+
+    def put_padding(length):
+        output_file.write(b"\0" * length)
+
+    filesize = 14 + 108 + height * width * 2
+
+    # BMP header
+    output_file.write(b"BM")
+    put_dword(filesize)
+    put_word(0)  # Creator 1
+    put_word(0)  # Creator 2
+    put_dword(14 + 108)  # Offset of bitmap data
+
+    # DIB header (BITMAPV4HEADER)
+    put_dword(108)  # sizeof(BITMAPV4HEADER)
+    put_long(width)
+    put_long(-height)
+    put_word(1)  # number of color planes (must be 1)
+    put_word(16)  # number of bits per pixel
+    put_dword(_BI_BITFIELDS)  # "compression"
+    put_dword(2 * width * height)  # size of raw bitmap data
+    put_long(11811)  # 72dpi -> pixels/meter
+    put_long(11811)  # 72dpi -> pixels/meter
+    put_dword(0)  # palette size
+    put_dword(0)  # important color count
+    put_dword(masks[0])  # red mask
+    put_dword(masks[1])  # green mask
+    put_dword(masks[2])  # blue mask
+    put_dword(0)  # alpha mask
+    put_dword(0)  # CS Type
+    put_padding(3 * 3 * 4)  # CIEXYZ infrmation
+    put_dword(144179)  # 2.2 gamma red
+    put_dword(144179)  # 2.2 gamma green
+    put_dword(144179)  # 2.2 gamma blue
+
+
+def capture_image_bmp(bitmap):
+    with open_next_image("bmp") as f:
+        swapped = np.frombuffer(bitmap, dtype=np.uint16)
+        swapped.byteswap(inplace=True)
+        write_header(f, bitmap.width, bitmap.height, _bitmask_rgb565)
+        f.write(swapped)
+
+
+display.auto_refresh = False
+old_record_pressed = True
+
+while True:
+    a_voltage = a.value * a.reference_voltage / 65535
+    cam.capture(bitmap)
+    bitmap.dirty()
+
+    record_pressed = abs(a_voltage - V_RECORD) < 0.05
+    display.refresh(minimum_frames_per_second=0)
+    if record_pressed and not old_record_pressed:
+        capture_image_bmp(bitmap)
+    old_record_pressed = record_pressed