iot

问题 I need the system to be secure. I tired to encode the image with base64 and sending the string via MQTT to Iot Core. Then decode the string with a cloud function and finally storage the decoded image in Google Cloud Storage. The problem is the limited size of a message in MQTT. Using a Cloud Function and then storage in Google Cloud Storage is not really secure, anyone could hit that url and I loos control of all the ESP32CAM comunication. Am I missing something? is there a really secure way

问题 I am having mosquitto broker running on Ubuntu on EC2. Also I did a change max_queued_messages 1000 and max_inflight_messages 10 in /etc/mosquitto/mosquitto.conf I am publishing to this broker with qos=2 and retain enabled . For publishing I am using mosquitto_pub -t 1 -m "{c:{d:\"pN\",m:\"Pr1\"}}" -r -q 2 . And subscriber side I am using org.eclipse.paho.android.service:1.0.2 library with same qos=2. and only providing single option by options.setMqttVersion(MqttConnectOptions.MQTT_VERSION_3

问题 I'm working on a IoT project. I've a Raspberry pi which send data to an IoTHub on Azure. That Hub forwards that data to an Azure Stream Analytics Job. In my query I try to aggregate(here an average) all the data in a TumblingWindow of 1 minute but as a Timestamp I use a custom datetime sent in the data. I've tried many things but nothing seemed to work. the stream job seems to ignore the datetime I provide and just aggregate everything based on the arrival time. Only when using the "Test"

问题 I'm trying to test MQTT-SN. I'm using Mosquitto Broker, Paho MQTT-SN Gateway and this library (https://github.com/S3ler/arduino-mqtt-sn-client) for the clients. I'm using an esp8266 as a client. With this client, I can connect, subscribe, receive from subscribed topics but I cant publish into topics memset(buffer, 0x0, buffer_length); mqttSnClient.publish(buffer, publishTopicName , qos); Every time I try to publish with this client, Mosquitto gives me Socket error on client <clientid>,

问题 I use MQTT+tls to connect the IoT device to the server with GPRS supported by SIM900. The IoT device connects to the server without any problem on HTTP or HTTPs. However, When I set up the ssl proxy on the server with Tomcat,the IoT device can get status of "send ok" successfully,but always gets "wait send ok ack timeout" error. The wireshark installed on the server can't capture any useful infomation. 回答1: on SIM900 you can't use TCP+SSL. That's why you can do it with HTTPS but you can't do

问题 As a mesh, a signal can propagate across devices. Naturally there must be a hop limit. How many node hops does OpenThread support? 回答1: The maximum path cost amount Thread Routers allowed by Thread is 16. Usable link costs between Routers may range from 1 to 4, with 1 being the best. As a result, the maximum number of hops between Routers with good links is 16. Considering that links to end devices are not included in the route cost, it is possible to add another hop at each end of the Router

问题 I'm designing a system with many devices using MQTT to connect to a central broker. There are some masters that can send requests to certain devices that are slaves. The request from one master is usually directed to one slave. The topic for requests could be: mysystem/slaveId/req , so the slaves can subscribe to this topic and master publishes to the same topic. Only the addressed slave will receive the request, as it should be. My question is how to decide the topic for responses. I'm in

问题 I'm designing a system with many devices using MQTT to connect to a central broker. There are some masters that can send requests to certain devices that are slaves. The request from one master is usually directed to one slave. The topic for requests could be: mysystem/slaveId/req , so the slaves can subscribe to this topic and master publishes to the same topic. Only the addressed slave will receive the request, as it should be. My question is how to decide the topic for responses. I'm in

问题 I'm designing a system with many devices using MQTT to connect to a central broker. There are some masters that can send requests to certain devices that are slaves. The request from one master is usually directed to one slave. The topic for requests could be: mysystem/slaveId/req , so the slaves can subscribe to this topic and master publishes to the same topic. Only the addressed slave will receive the request, as it should be. My question is how to decide the topic for responses. I'm in

问题 I am using a Python client with paho-mqtt to publish in this specific topic of Google Cloud IoT: projects/my_project/topics/sm1 . My code is below, based on examples of the Google IoT documentation: import paho.mqtt.client as mqtt import ssl, random, jwt_maker from time import sleep root_ca = './../roots.pem' public_crt = './../my_cert.pem' private_key = './../my_pr.pem' mqtt_url = "mqtt.googleapis.com" mqtt_port = 8883 mqtt_topic = "/projects/my_project/topics/sm1" project_id = "my_project"