Add Adafruit IO Example

This pushes a JPEG image at 800x600 resolution to Adafruit IO every 3
seconds.

Author: jepler

examples/ov2640_aio_kaluga_1_3.py

@@ -0,0 +1,79 @@
+# 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(!)
+
+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 os
+import time
+import binascii
+
+import board
+import busio
+import wifi
+import socketpool
+import ssl
+import adafruit_ov2640
+from secrets import secrets
+import adafruit_minimqtt.adafruit_minimqtt as MQTT
+from adafruit_io.adafruit_io import IO_MQTT
+
+feed_name = "image"
+
+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.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
+
+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("image", encoded_data)
+
+    print("Waiting 3s")
+    time.sleep(3)