add jpeg example for pico

Author: jerryneedell

examples/ov2640_jpeg_sd_pico_st7789_2in.py

@@ -0,0 +1,161 @@
+# SPDX-FileCopyrightText: 2017 Scott Shawcroft, written for Adafruit Industries
+# SPDX-FileCopyrightText: Copyright (c) 2021 Jeff Epler for Adafruit Industries
+#
+# SPDX-License-Identifier: Unlicense
+
+"""
+Display an image on the LCD, then record an image when a button is pressed/held.
+
+Uses the SD Card present on the 2inch st7789 breakout board
+
+This example also requires an SD card breakout wired as follows:
+SPI BUS - same as the ST7789 -- with MISO connected
+ * GP2: SD Clock Input
+ * GP3: SD Serial Input (MOSI)
+ * GP4: SD Serial Output (MISO)
+ * GP5: SD Chip Select
+
+A button is needed to trigger the capture
+Attach a button to  GROUND and GP22
+
+Insert a CircuitPython-compatible SD card before powering on the Kaluga.
+Press the "Record" button on the audio daughterboard to take a photo.
+"""
+
+import time
+from displayio import (
+    Bitmap,
+    Group,
+    TileGrid,
+    FourWire,
+    release_displays,
+    ColorConverter,
+    Colorspace,
+)
+
+from adafruit_st7789 import ST7789
+import board
+import busio
+import digitalio
+import adafruit_ov2640
+import sdcardio
+import storage
+import os
+
+release_displays()
+# Set up the display (You must customize this block for your display!)
+spi = busio.SPI(clock=board.GP2, MOSI=board.GP3, MISO=board.GP4)
+# setup the SD Card
+sd_cs = board.GP5
+sdcard = sdcardio.SDCard(spi, sd_cs)
+vfs = storage.VfsFat(sdcard)
+storage.mount(vfs, "/sd")
+# setup the button
+button = digitalio.DigitalInOut(board.GP22)
+button.pull = digitalio.Pull.UP
+
+display_bus = FourWire(spi, command=board.GP0, chip_select=board.GP1, reset=None)
+display = ST7789(display_bus, width=320, height=240, rotation=270)
+display.auto_refresh = False
+
+# Ensure the camera is shut down, so that it releases the SDA/SCL lines,
+# then create the configuration I2C bus
+
+with digitalio.DigitalInOut(board.GP10) as reset:
+    reset.switch_to_output(False)
+    time.sleep(0.001)
+    bus = busio.I2C(board.GP9, board.GP8)
+
+# Set up the camera (you must customize this for your board!)
+cam = adafruit_ov2640.OV2640(
+    bus,
+    data_pins=[
+        board.GP12,
+        board.GP13,
+        board.GP14,
+        board.GP15,
+        board.GP16,
+        board.GP17,
+        board.GP18,
+        board.GP19,
+    ],  # [16]     [org] etc
+    clock=board.GP11,  # [15]     [blk]
+    vsync=board.GP7,  # [10]     [brn]
+    href=board.GP21,  # [27/o14] [red]
+    mclk=board.GP20,  # [16/o15]
+    shutdown=None,
+    reset=board.GP10,
+)  # [14]
+
+width = display.width
+height = display.height
+
+cam.size = adafruit_ov2640.OV2640_SIZE_QQVGA
+# cam.test_pattern = True
+bitmap = Bitmap(cam.width, cam.height, 65536)
+
+print(width, height, cam.width, cam.height)
+if bitmap is None:
+    raise SystemExit("Could not allocate a bitmap")
+
+g = Group(scale=1, x=(width - cam.width) // 2, y=(height - cam.height) // 2)
+tg = TileGrid(
+    bitmap, pixel_shader=ColorConverter(input_colorspace=Colorspace.RGB565_SWAPPED)
+)
+g.append(tg)
+display.show(g)
+
+display.auto_refresh = False
+
+
+def exists(filename):
+    try:
+        os.stat(filename)
+        return True
+    except OSError as e:
+        return False
+
+
+_image_counter = 0
+
+
+def open_next_image():
+    global _image_counter
+    while True:
+        filename = f"/sd/img{_image_counter:04d}.jpg"
+        _image_counter += 1
+        if exists(filename):
+            continue
+        print("#", filename)
+        return open(filename, "wb")
+
+
+def capture_image():
+    old_size = cam.size
+    old_colorspace = cam.colorspace
+
+    try:
+        cam.size = adafruit_ov2640.OV2640_SIZE_QVGA
+        cam.colorspace = adafruit_ov2640.OV2640_COLOR_JPEG
+        b = bytearray(cam.capture_buffer_size)
+        jpeg = cam.capture(b)
+
+        print(f"Captured {len(jpeg)} bytes of jpeg data")
+        with open_next_image() as f:
+            f.write(jpeg)
+    finally:
+        cam.size = old_size
+        cam.colorspace = old_colorspace
+
+
+def main():
+    display.auto_refresh = False
+    while True:
+        if not button.value:  # button pressed
+            capture_image()
+        cam.capture(bitmap)
+        bitmap.dirty()
+        display.refresh(minimum_frames_per_second=0)
+
+
+main()