Azure/azure-event-hubs-node

device status

Closed this issue · 5 comments

anthonyvercolano commented

Willin, could you please give a bit more of the scenario that you are thinking of?

willin commented 
CREATE TABLE `device` (
  `did` varchar(32) NOT NULL DEFAULT '',
  `state` tinyint(1) unsigned NOT NULL DEFAULT 0,
  PRIMARY KEY (`did`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

state: 0 means offline, state: 1 means online.

when device connected to iothub(via mqtt or any else), a trigger event update the table set state:1, disconnected set state:0.

willin commented

here is an example of sending message

const clientFromConnectionString = require('azure-iot-device-mqtt').clientFromConnectionString;
const Message = require('azure-iot-device').Message;
const connectionString = 'HostName=[修改连接主机];DeviceId=[deviceID];SharedAccessKey=[连接密钥]';
const client = clientFromConnectionString(connectionString);
function printResultFor(op) {
  return function printResult(err, res) {
    if (err) console.log(`${op} error: ${err.toString()}`);
    if (res) console.log(`${op} status: ${res.constructor.name}`);
  };
}
const connectCallback = function (err) {
  if (err) {
    console.log(`Could not connect: ${err}`);
  } else {
    console.log('Client connected');
    // Create a message and send it to the IoT Hub every second
    setInterval(() => {
      const windSpeed = 10 + (Math.random() * 4);
      const data = JSON.stringify({ deviceId: 'myFirstNodeDevice', windSpeed });
      const message = new Message(data);
      // 随机发送到路由或默认事件上
      if (Math.round(Math.random()) === 1) {
        message.properties.add('route', 'test');
      }
      console.log(`Sending message: ${message.getData()}`);
      client.sendEvent(message, printResultFor('send'));
    }, 1000);
  }
};
client.open(connectCallback);

how to send mqtt Last Will / Testament message to specific route?

willin commented 
const receiver = await client.createReceiver('$Default', partitionId, {
   // how to start after last disconnected time 
   startAfterTime: Date.now() // this problem is also very important too.
});

@anthonyvercolano

pierreca commented

@willin I believe this is the same question as Azure/azure-iot-sdk-node#65. If that's the case please let's just leave only one open. I replied over there.