cloudprog-hw4/led_control.py
2023-05-01 15:10:04 +08:00

186 lines
4.9 KiB
Python

import sys
import json
import uuid
import asyncio
import datetime
import traceback
import cv2
import requests
from awscrt import mqtt
from awsiot import mqtt_connection_builder
DEBUG = 0
UUID = f"cloudprog-{uuid.uuid4()}"
ENDPOINT = ""
CA = ""
CERT = ""
PRIVKEY = ""
LED_TOPIC = ""
# https://aws.amazon.com/tw/blogs/iot/securely-ingesting-large-sized-payloads-from-iot-devices-to-the-aws-cloud/
S3_UPLOAD_TOPIC = ""
S3_URL_TOPIC = ""
FORMAT = "jpg"
filename = None
cam = cv2.VideoCapture(0)
if not DEBUG:
import RPi.GPIO as GPIO
LED_PIN = 32
GPIO.setmode(GPIO.BOARD)
GPIO.setup(LED_PIN, GPIO.OUT)
# Callback when connection is accidentally lost.
def on_connection_interrupted(connection, error, **kwargs):
print("Connection interrupted. error: {}".format(error))
# Callback when an interrupted connection is re-established.
def on_connection_resumed(connection, return_code, session_present, **kwargs):
print("Connection resumed. return_code: {} session_present: {}".format(return_code, session_present))
if return_code == mqtt.ConnectReturnCode.ACCEPTED and not session_present:
print("Session did not persist. Resubscribing to existing topics...")
resubscribe_future, _ = connection.resubscribe_existing_topics()
# Cannot synchronously wait for resubscribe result because we're on the connection's event-loop thread,
# evaluate result with a callback instead.
resubscribe_future.add_done_callback(on_resubscribe_complete)
def on_resubscribe_complete(resubscribe_future):
resubscribe_results = resubscribe_future.result()
print("Resubscribe results: {}".format(resubscribe_results))
for topic, qos in resubscribe_results['topics']:
if qos is None:
print("Server rejected resubscribe to topic: {}".format(topic))
# Callback when the subscribed topic receives a message
def on_message_received(topic, payload, dup, qos, retain, **kwargs):
# print("Received message from topic '{}': {}".format(topic, payload))
if topic.endswith("led"):
parse_led_payload(payload)
elif topic.endswith("s3/url"):
parse_s3_url_payload(payload)
def parse_led_payload(payload):
data = json.loads(payload.decode())
if data.get("faces"):
led_control(True)
else:
led_control(False)
def led_control(light):
print(["Light off", "Light on"][light])
if not DEBUG:
GPIO.output(LED_PIN, GPIO.HIGH if light else GPIO.LOW)
def parse_s3_url_payload(payload):
data = json.loads(payload.decode())
put_presigned_s3_url(data["url"], take_picture())
def take_picture():
cam.open()
ret, frame = cam.read()
ret, img = cv2.imencode(FORMAT, frame)
cam.release()
return img.tobytes()
def put_presigned_s3_url(url, img_bytes):
res = requests.put(url, data=img_bytes)
print(f"Put to S3. status code: {res.status_code}")
return res
async def main():
global filename
# create MQTT connection
mqtt_connection = mqtt_connection_builder.mtls_from_path(
endpoint=ENDPOINT,
cert_filepath=CERT,
pri_key_filepath=PRIVKEY,
ca_filepath=CA,
on_connection_interrupted=on_connection_interrupted,
on_connection_resumed=on_connection_resumed,
client_id=UUID
)
connect_future = mqtt_connection.connect()
connect_result = connect_future.result()
print(f"{UUID} is connected!")
# subscribe to MQTT topic
subscribe_future, packet_id = mqtt_connection.subscribe(
topic=LED_TOPIC,
qos=mqtt.QoS.AT_LEAST_ONCE,
callback=on_message_received
)
subscribe_result = subscribe_future.result()
print(subscribe_result)
print(f"Subscribed to {LED_TOPIC}")
subscribe_future, packet_id = mqtt_connection.subscribe(
topic=S3_URL_TOPIC,
qos=mqtt.QoS.AT_LEAST_ONCE,
callback=on_message_received
)
subscribe_result = subscribe_future.result()
print(subscribe_result)
print(f"Subscribed to {S3_URL_TOPIC}")
while True:
command = input("> ")
if command == "p":
filename = datetime.datetime.strftime(datetime.datetime.now(), "%Y-%m-%d-%H-%M-%S") + "." + FORMAT
publish_future, packet_id = mqtt_connection.publish(
topic=S3_UPLOAD_TOPIC,
payload=json.dumps({ "filename": filename }),
qos=mqtt.QoS.AT_LEAST_ONCE
)
publish_result = publish_future.result()
print(publish_result)
print(f"Upload request {filename} sent!")
elif command == "q":
break
def handler(loop, context):
e = context['exception']
print(*traceback.format_exception(None, e, e.__traceback__), file=sys.stderr, flush=True)
if not DEBUG:
GPIO.cleanup()
loop.stop()
# run
loop = asyncio.get_event_loop()
loop.set_exception_handler(handler)
loop.create_task(main())
loop.run_forever()