Use iothub-explorer to send and receive messages between your device and IoT Hub

[!NOTE] Before you start this tutorial, make sure you’ve completed Setup your device. By Setup your device, you set up your IoT device and IoT hub, and deploy a sample application to run on your device. The application sends collected sensor data to your IoT hub.

iothub-explorer has a handful of commands that makes IoT Hub management easier. This tutorial focuses on how to use iothub-explorer to send and receive messages between your device and your IoT hub.

What you will learn

You learn how to use iothub-explorer to monitor device-to-cloud messages and to send cloud-to-device messages. Device-to-cloud messages could be sensor data that your device collects and then sends to your IoT hub. Cloud-to-device messages could be commands that your IoT hub sends to your device to blink an LED that is connected to your device.

What you will do

• Use iothub-explorer to monitor device-to-cloud messages.
• Use iothub-explorer to send cloud-to-device messages.

What you need

• Tutorial Setup your device completed which covers the following requirements:
  • An active Azure subscription.
  • An Azure IoT hub under your subscription.
  • A client application that sends messages to your Azure IoT hub.
• iothub-explorer. (Install iothub-explorer)

Monitor device-to-cloud messages

To monitor messages that are sent from your device to your IoT hub, follow these steps:

1. Open a console window.

2. Run the following command:

   iothub-explorer monitor-events <device-id> --login "<IoTHubConnectionString>"
   

   [!Note] Get <device-id> and <IoTHubConnectionString> from your IoT hub. Make sure you've finished the previous tutorial. Or you can try to use iothub-explorer monitor-events <device-id> --login "HostName=<my-hub>.azure-devices.net;SharedAccessKeyName=<my-policy>;SharedAccessKey=<my-policy-key>" if you have HostName, SharedAccessKeyName and SharedAccessKey.

Send cloud-to-device messages

To send a message from your IoT hub to your device, follow these steps:

1. Open a console window.

2. Start a session on your IoT hub by running the following command:

   iothub-explorer login <IoTHubConnectionString>
   

3. Send a message to your device by running the following command:

   iothub-explorer send <device-id> <message>
   

The command blinks the LED that is connected to your device and sends the message to your device.

[!Note] There is no need for the device to send a separate ack command back to your IoT hub upon receiving the message.

Next steps

You’ve learned how to monitor device-to-cloud messages and send cloud-to-device messages between your IoT device and Azure IoT Hub.