add another example for manual focus

Author: jerryneedell

examples/ov5640_jpeg_capture_manual_focus.py

@@ -0,0 +1,115 @@
+# SPDX-FileCopyrightText: Copyright (c) 2023 Limor Fried for Adafruit Industries
+#
+# SPDX-License-Identifier: Unlicense
+"""
+This demo is designed for the Raspberry Pi Pico and Camera PiCowbell
+When the shutter is pressed, a prompt is given to enter a step
+for the focus. Enter a value 0-255 to set the focus or
+enter a value >255 to execute an autofocus.
+After the value is input, an image is captured and saved
+to the microSD card.
+"""
+
+import os
+import time
+import busio
+import board
+import digitalio
+import keypad
+import sdcardio
+import storage
+import adafruit_ov5640
+
+print("Initializing SD card")
+sd_spi = busio.SPI(clock=board.GP18, MOSI=board.GP19, MISO=board.GP16)
+sd_cs = board.GP17
+sdcard = sdcardio.SDCard(sd_spi, sd_cs)
+vfs = storage.VfsFat(sdcard)
+storage.mount(vfs, "/sd")
+
+print("construct bus")
+i2c = busio.I2C(board.GP5, board.GP4)
+print("construct camera")
+reset = digitalio.DigitalInOut(board.GP14)
+cam = adafruit_ov5640.OV5640(
+    i2c,
+    data_pins=(
+        board.GP6,
+        board.GP7,
+        board.GP8,
+        board.GP9,
+        board.GP10,
+        board.GP11,
+        board.GP12,
+        board.GP13,
+    ),
+    clock=board.GP3,
+    vsync=board.GP0,
+    href=board.GP2,
+    mclk=None,
+    shutdown=None,
+    reset=reset,
+    size=adafruit_ov5640.OV5640_SIZE_VGA,
+)
+print("print chip id")
+print(cam.chip_id)
+
+keys = keypad.Keys((board.GP22,), value_when_pressed=False, pull=True)
+
+
+def exists(filename):
+    try:
+        os.stat(filename)
+        return True
+    except OSError as _:
+        return False
+
+
+_image_counter = 0
+
+
+def open_next_image():
+    global _image_counter  # pylint: disable=global-statement
+    while True:
+        filename = f"/sd/img{_image_counter:04d}.jpg"
+        _image_counter += 1
+        if exists(filename):
+            continue
+        print("# writing to", filename)
+        return open(filename, "wb")
+
+
+cam.colorspace = adafruit_ov5640.OV5640_COLOR_JPEG
+cam.quality = 3
+b = bytearray(cam.capture_buffer_size)
+
+cam.autofocus()
+print("AF Status: ", cam.autofocus_status, cam.autofocus_vcm_step)
+
+jpeg = cam.capture(b)
+
+while True:
+    shutter = keys.events.get()
+    # event will be None if nothing has happened.
+    if shutter:
+        if shutter.pressed:
+            """Captures an image and send it to Adafruit IO."""
+            step = int(input("enter AF step:"))
+            if step > 255:
+                # Force autofocus and capture a JPEG image
+                cam.autofocus()
+                print("AF Status: ", cam.autofocus_status, cam.autofocus_vcm_step)
+            else:
+                cam.autofocus_vcm_step = step
+            print("AF Status: ", cam.autofocus_status, cam.autofocus_vcm_step)
+            time.sleep(0.01)
+            jpeg = cam.capture(b)
+            print(f"Captured {len(jpeg)} bytes of jpeg data")
+            print(f" (had allocated {cam.capture_buffer_size} bytes")
+            print(f"Resolution {cam.width}x{cam.height}")
+            try:
+                with open_next_image() as f:
+                    f.write(jpeg)
+                print("# Wrote image")
+            except OSError as e:
+                print(e)