mqtt

9月18日，腾讯宣布开源自主研发的轻量级物联网实时操作系统 Ten centOS tiny。TencentOS tiny是腾讯面向物联网领域开发的实时操作系统，具有低功耗，低资源占用，模块化，安全可靠等特点，可有效提升物联网终端产品开发效率。TencentOS tiny 提供精简的 RTOS 内核，内核组件可裁剪可配置，可快速移植到多种主流 MCU (如STM32全系列)及模组芯片上。而且，基于RTOS内核提供了丰富的物联网组件，内部集成主流物联网协议栈（如 CoAP/MQTT/TLS/DTLS/LoRaWAN/NB-IoT 等），可助力物联网终端设备及业务快速接入腾讯云物联网平台。 TencentOS tiny 主体架构图，从下到上主要包括： CPU 库 ：TencentOS tiny 支持的 CPU IP 核架构，当前主要支持 ARM Cortex M0/3/4/7。 驱动管理层 ：包括板级支持包（BSP，主要由 MCU 芯片厂家开发与维护）、硬件抽象（HAL，主要由 TencentOS tiny提供，方便不同芯片的适配与移植）、设备驱动（Drivers，例如 Wi-Fi、GPRS、LoRa 等模块的驱动程序）。 内核 ：TencentOS tiny 实时内核包括任务管理、实时调度、时间管理、中断管理、内存管理、异常处理、软件定时器、链表、消息队列、信号量、互斥锁

I am trying to connect an Unity3d Android application to an ActiveMQ server using MQTT protocol. In the log attached below I can see that the server is refusing me the connection. I have correctly portforwarded the required port to be accessible from outside. I have also tried to connect from the local network using the device's wi-fi. I am using a MQTT library for unity which can be found here: https://m2mqtt4unity.codeplex.com/ Currently the same application, the example that can be found in https://m2mqtt4unity.codeplex.com/documentation , is working fine in the unity editor and in

I'm trying to use an MQTT client on Android application but I cannot get it working. My MQTT client is 0.4.0 and my Android is 4.0.3. The app is very simple: it has an EditText and a button to publish the text. Further it has a TextView to show the received message. Every time is click on the "Publish" button, the "connection lost" message is shown, sometimes two or three times, as it tried to connect multiple times and then disconnected. Also, without clicking on the button, if I try to publish a message on the "123456789" topic via another client nothing happen (no "message arrived" message

I am able to subscribe to the mosquitto broker with this Java code, without username and password. Now, i would like to subscribe to an emqttd broker which requires some dummy username and password. How can i do this?. Thanks. http://tgrall.github.io/blog/2017/01/02/getting-started-with-mqtt/#disqus_thread https://github.com/emqtt/emqttd package com.mapr.demo.mqtt.simple; import org.eclipse.paho.client.mqttv3.MqttClient; import org.eclipse.paho.client.mqttv3.MqttException; public class Subscriber { public static void main(String[] args) throws MqttException { System.out.println("== START

I'm trying to setup a MQTT Microservice using NestJS according to the docs . I've started a working Mosquitto Broker using Docker and verified it's operability using various MQTT clients. Now, when I start the NestJS service it seems to be connecting correctly (mqqt.fx shows new client), yet I am unable to receive any messages in my controllers. This is my bootstrapping, just like in the docs: main.ts async function bootstrap() { const app = await NestFactory.createMicroservice(AppModule, { transport: Transport.MQTT, options: { host: 'localhost', port: 1883, protocol: 'tcp' } }); app.listen(()

I have a Node-RED application that is bound to an IOT Foundation (iotf) service. I can receive events from devices and handle them appropriately. However, I am now interested in sending commands back to my devices and am having some problems. Nothing is showing up at the device, but by creating an IOTF in node, I can confirm that the command is passing through iotf. I can definitely get commands to pass through iotf using pure python, as the follow code works well: Client code: #!/usr/bin/python import ibmiotf.device from time import sleep options = { "org": "cgmncc", "type": "table", "id":

物联网是在互联网的基础上延伸和扩展的一种网络，其用户端延伸和扩展到了任何物品之间，彼此进行信息交换和通信，目的是实现所有物品与网络的连接，从而方便识别、管理和控制。无线物联网的特点包括：全面感知、实时准确传递物品信息、利用智能计算技术对海量数据进行分析和处理，以实现智能化控制。由于物联网中的很多设备都是资源受限型的，即 只有少量的内存空间和有限的计算能力 ，所以传统的HTTP协议应用在物联网上就显得过于庞大而不适用。 MQTT协议和CoAP协议都是物联网中比较流行的协议，都 对传输量做了很大的精简，传输开销小 ，以适应物理网的网络环境。 CoAP （Constrained Application Protocol 受限应用协议） CoAP是6LowPAN协议栈中的应用层协议。COAP协议网络传输层由TCP改为UDP。 COAP是二进制格式的，HTTP是文本格式的，COAP比HTTP更加紧凑。 轻量化，COAP最小长度仅仅4B，一个HTTP的头都几十个B了。 支持可靠传输，数据重传，块传输。 确保数据可靠到达。 支持IP多播, 即可以同时向多个设备发送请求。 非长连接通信，适用于低功耗物联网场景。 MQTT （Message Queuing Telemetry Transport 消息队列遥测传输） 为硬件性能低下的远程设备以及网络状况糟糕的情况下而设计的 发布/订阅型消息协议