Add example for SAOLA board

examples/ov2640_aio_saola.py

@@ -0,0 +1,86 @@
+# SPDX-FileCopyrightText: 2017 Scott Shawcroft, written for Adafruit Industries
+# SPDX-FileCopyrightText: Copyright (c) 2021 Jeff Epler for Adafruit Industries
+#
+# SPDX-License-Identifier: Unlicense
+
+"""
+This exampl us for the Espressif Soala Wrover with an OV2640 Camera
+
+This example requires that your WIFI and Adafruit IO credentials be configured
+in CIRCUITPY/secrets.py, and that you have created a feed called "image" with
+history disabled.
+
+The maximum image size is 100kB after base64 encoding, or about 65kB before
+base64 encoding.  In practice, "SVGA" (800x600) images are typically around
+40kB even though the "capture_buffer_size" (theoretical maximum size) is
+(width*height/5) bytes or 96kB.
+"""
+
+import binascii
+import ssl
+import time
+from secrets import secrets  # pylint: disable=no-name-in-module
+
+import board
+import busio
+import digitalio
+import wifi
+import socketpool
+import adafruit_minimqtt.adafruit_minimqtt as MQTT
+from adafruit_io.adafruit_io import IO_MQTT
+import adafruit_ov2640
+
+feed_name = "image-saola-ov2640"
+
+print("Connecting to WIFI")
+wifi.radio.connect(secrets["ssid"], secrets["password"])
+pool = socketpool.SocketPool(wifi.radio)
+
+print("Connecting to Adafruit IO")
+mqtt_client = MQTT.MQTT(
+    broker="io.adafruit.com",
+    username=secrets["aio_username"],
+    password=secrets["aio_key"],
+    socket_pool=pool,
+    ssl_context=ssl.create_default_context(),
+)
+mqtt_client.connect()
+io = IO_MQTT(mqtt_client)
+
+bus = busio.I2C(scl=board.IO7, sda=board.IO8)
+cam = adafruit_ov2640.OV2640(
+    bus,
+    data_pins=(
+        board.IO36,
+        board.IO37,
+        board.IO41,
+        board.IO42,
+        board.IO39,
+        board.IO40,
+        board.IO21,
+        board.IO38,
+    ),
+    clock=board.IO33,
+    vsync=board.IO2,
+    href=board.IO3,
+    mclk=board.IO1,
+    mclk_frequency=20_000_000,
+    size=adafruit_ov2640.OV2640_SIZE_QVGA,
+)
+
+cam.flip_x = False
+cam.flip_y = False
+
+cam.size = adafruit_ov2640.OV2640_SIZE_SVGA
+cam.colorspace = adafruit_ov2640.OV2640_COLOR_JPEG
+jpeg_buffer = bytearray(cam.capture_buffer_size)
+while True:
+    jpeg = cam.capture(jpeg_buffer)
+    print(f"Captured {len(jpeg)} bytes of jpeg data")
+
+    # b2a_base64() appends a trailing newline, which IO does not like
+    encoded_data = binascii.b2a_base64(jpeg).strip()
+    print(f"Expanded to {len(encoded_data)} for IO upload")
+    io.publish(feed_name, encoded_data)
+    print("Waiting 10s")
+    time.sleep(10)