为什么我不能使用 Python(使用此代码)通过 MQTT 将图像发送到 Google Cloud IoT Core?
Why can't I send image to Google Cloud IoT Core with MQTT using Python (with this code)?
下面是我尝试使用 MQTT 将图像发送到 Google Cloud IoT Core。我已阅读以下对我有所帮助的帖子,但我的代码仍然无法正常工作: and How can I publish a file using Mosquitto in python?.
我想我的错误要么与 client.publish
中的 qos
有关,要么与我使用循环的方式有关,但恐怕我对这些因素的试验没有帮助到目前为止我(尝试 qos
= 0/1/2 和例如 client.loop_forever()
)。我的图像是 1.2 Mb,所以据我所知这应该不是问题。
#!/usr/bin/python
from picamera import PiCamera
import datetime
import time
import jwt
import paho.mqtt.client as mqtt
from time import sleep
# Define some project-based variables to be used below. This should be the only
# block of variables that you need to edit in order to run this script
ssl_private_key_filepath = 'FILE1.pem'
ssl_algorithm = 'RS256' # Either RS256 or ES256
root_cert_filepath = 'FILE2.PEM'
project_id = 'PROJECT_ID'
gcp_location = 'LOCATION'
registry_id = 'REG_ID'
device_id = 'DEVICE_ID'
# end of user-variables
run = True
cur_time = datetime.datetime.utcnow()
def create_jwt():
token = {
'iat': cur_time,
'exp': cur_time + datetime.timedelta(minutes=60),
'aud': project_id
}
with open(ssl_private_key_filepath, 'r') as f:
private_key = f.read()
return jwt.encode(token, private_key, ssl_algorithm)
_CLIENT_ID = 'projects/{}/locations/{}/registries/{}/devices/{}'.format(project_id, gcp_location, registry_id, device_id)
_MQTT_TOPIC = '/devices/{}/events'.format(device_id)
client = mqtt.Client(client_id=_CLIENT_ID)
# authorization is handled purely with JWT, no user/pass, so username can be whatever
client.username_pw_set(
username='unused',
password=create_jwt())
def error_str(rc):
return '{}: {}'.format(rc, mqtt.error_string(rc))
def on_connect(unusued_client, unused_userdata, unused_flags, rc):
print('on_connect', error_str(rc))
def on_publish(unused_client, unused_userdata, unused_mid):
print('on_publish')
run = False
client.on_connect = on_connect
client.on_publish = on_publish
client.tls_set(ca_certs=root_cert_filepath) # Replace this with 3rd party cert if that was used when creating registry
client.connect('mqtt.googleapis.com', 8883)
camera = PiCamera()
camera.start_preview()
sleep(5)
camera.capture('/tmp/picture.jpg')
camera.stop_preview()
with open("/tmp/picture.jpg", 'rb') as f:
imagestring = f.read()
byteArray = bytes(imagestring)
try:
client.publish(_MQTT_TOPIC, byteArray, qos=2)
except:
print('Error')
while run:
client.loop()
client.disconnect()
@Aaron 提供了答案
"1.2Mb is way too big..."
Telemetry event payload limit 为 256 KB,无法增加
下面是我尝试使用 MQTT 将图像发送到 Google Cloud IoT Core。我已阅读以下对我有所帮助的帖子,但我的代码仍然无法正常工作:
我想我的错误要么与 client.publish
中的 qos
有关,要么与我使用循环的方式有关,但恐怕我对这些因素的试验没有帮助到目前为止我(尝试 qos
= 0/1/2 和例如 client.loop_forever()
)。我的图像是 1.2 Mb,所以据我所知这应该不是问题。
#!/usr/bin/python
from picamera import PiCamera
import datetime
import time
import jwt
import paho.mqtt.client as mqtt
from time import sleep
# Define some project-based variables to be used below. This should be the only
# block of variables that you need to edit in order to run this script
ssl_private_key_filepath = 'FILE1.pem'
ssl_algorithm = 'RS256' # Either RS256 or ES256
root_cert_filepath = 'FILE2.PEM'
project_id = 'PROJECT_ID'
gcp_location = 'LOCATION'
registry_id = 'REG_ID'
device_id = 'DEVICE_ID'
# end of user-variables
run = True
cur_time = datetime.datetime.utcnow()
def create_jwt():
token = {
'iat': cur_time,
'exp': cur_time + datetime.timedelta(minutes=60),
'aud': project_id
}
with open(ssl_private_key_filepath, 'r') as f:
private_key = f.read()
return jwt.encode(token, private_key, ssl_algorithm)
_CLIENT_ID = 'projects/{}/locations/{}/registries/{}/devices/{}'.format(project_id, gcp_location, registry_id, device_id)
_MQTT_TOPIC = '/devices/{}/events'.format(device_id)
client = mqtt.Client(client_id=_CLIENT_ID)
# authorization is handled purely with JWT, no user/pass, so username can be whatever
client.username_pw_set(
username='unused',
password=create_jwt())
def error_str(rc):
return '{}: {}'.format(rc, mqtt.error_string(rc))
def on_connect(unusued_client, unused_userdata, unused_flags, rc):
print('on_connect', error_str(rc))
def on_publish(unused_client, unused_userdata, unused_mid):
print('on_publish')
run = False
client.on_connect = on_connect
client.on_publish = on_publish
client.tls_set(ca_certs=root_cert_filepath) # Replace this with 3rd party cert if that was used when creating registry
client.connect('mqtt.googleapis.com', 8883)
camera = PiCamera()
camera.start_preview()
sleep(5)
camera.capture('/tmp/picture.jpg')
camera.stop_preview()
with open("/tmp/picture.jpg", 'rb') as f:
imagestring = f.read()
byteArray = bytes(imagestring)
try:
client.publish(_MQTT_TOPIC, byteArray, qos=2)
except:
print('Error')
while run:
client.loop()
client.disconnect()
@Aaron 提供了答案
"1.2Mb is way too big..."
Telemetry event payload limit 为 256 KB,无法增加