Connect Raspberry Pi to Azure IoT Hub (C)

In this tutorial, you begin by learning the basics of working with Raspberry Pi that's running Raspbian. You then learn how to seamlessly connect your devices to the cloud by using Azure IoT Hub. For Windows 10 IoT Core samples, go to the Windows Dev Center.

Don't have a kit yet? Try Raspberry Pi online simulator. Or buy a new kit here.

What you do

  • Create an IoT hub.

  • Register a device for Pi in your IoT hub.

  • Setup Raspberry Pi.

  • Run a sample application on Pi to send sensor data to your IoT hub.

Connect Raspberry Pi to an IoT hub that you create. Then you run a sample application on Pi to collect temperature and humidity data from a BME280 sensor. Finally, you send the sensor data to your IoT hub.

What you learn

  • How to create an Azure IoT hub and get your new device connection string.

  • How to connect Pi with a BME280 sensor.

  • How to collect sensor data by running a sample application on Pi.

  • How to send sensor data to your IoT hub.

What you need

What you need

  • The Raspberry Pi 2 or Raspberry Pi 3 board.

  • An active Azure subscription. If you don't have an Azure account, create a free Azure trial account in just a few minutes.

  • A monitor, a USB keyboard, and mouse that connect to Pi.

  • A Mac or a PC that is running Windows or Linux.

  • An Internet connection.

  • A 16 GB or above microSD card.

  • A USB-SD adapter or microSD card to burn the operating system image onto the microSD card.

  • A 5-volt 2-amp power supply with the 6-foot micro USB cable.

The following items are optional:

  • An assembled Adafruit BME280 temperature, pressure, and humidity sensor.

  • A breadboard.

  • 6 F/M jumper wires.

  • A diffused 10-mm LED.

Note

These items are optional because the code sample supports simulated sensor data.

Create an IoT hub

This section describes how to create an IoT hub using the Azure portal.

  1. Sign in to the Azure portal.

  2. From the Azure homepage, select the + Create a resource button, and then enter IoT Hub in the Search the Marketplace field.

  3. Select IoT Hub from the search results, and then select Create.

  4. On the Basics tab, complete the fields as follows:

    • Subscription: Select the subscription to use for your hub.

    • Resource Group: Select a resource group or create a new one. To create a new one, select Create new and fill in the name you want to use. To use an existing resource group, select that resource group. For more information, see Manage Azure Resource Manager resource groups.

    • Region: Select the region in which you want your hub to be located. Select the location closest to you.

    • IoT Hub Name: Enter a name for your hub. This name must be globally unique. If the name you enter is available, a green check mark appears.

    Important

    Because the IoT hub will be publicly discoverable as a DNS endpoint, be sure to avoid entering any sensitive or personally identifiable information when you name it.

    Create a hub in the Azure portal

  5. Select Next: Size and scale to continue creating your hub.

    Set the size and scale for a new hub using the Azure portal

    This screen allows you to set the following values:

    • Pricing and scale tier: Your selected tier. You can choose from several tiers, depending on how many features you want and how many messages you send through your solution per day. The free tier is intended for testing and evaluation. It allows 500 devices to be connected to the hub and up to 8,000 messages per day. Each Azure subscription can create one IoT hub in the free tier.

    • IoT Hub units: The number of messages allowed per unit per day depends on your hub's pricing tier. For example, if you want the hub to support ingress of 700,000 messages, you choose two S1 tier units. For details about the other tier options, see Choosing the right IoT Hub tier.

    • Advanced Settings > Device-to-cloud partitions: This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. Most hubs need only four partitions.

  6. For this article, accept the default choices, and then select Review + create to review your choices. You see something similar to this screen.

    Review information for creating the new hub

  7. Select Create to create your new hub. Creating the hub takes a few minutes.

Register a new device in the IoT hub

In this section, you create a device identity in the identity registry in your IoT hub. A device cannot connect to a hub unless it has an entry in the identity registry. For more information, see the IoT Hub developer guide.

  1. In your IoT hub navigation menu, open IoT Devices, then select New to add a device in your IoT hub.

    Create device identity in portal

  2. In Create a device, provide a name for your new device, such as myDeviceId, and select Save. This action creates a device identity for your IoT hub.

    Add a new device

    Important

    The device ID may be visible in the logs collected for customer support and troubleshooting, so make sure to avoid any sensitive information while naming it.

  3. After the device is created, open the device from the list in the IoT devices pane. Copy the Primary Connection String to use later.

    Device connection string

Note

The IoT Hub identity registry only stores device identities to enable secure access to the IoT hub. It stores device IDs and keys to use as security credentials, and an enabled/disabled flag that you can use to disable access for an individual device. If your application needs to store other device-specific metadata, it should use an application-specific store. For more information, see IoT Hub developer guide.

Set up Raspberry Pi

Now set up the Raspberry Pi.

Install the Raspbian operating system for Pi

Prepare the microSD card for installation of the Raspbian image.

  1. Download Raspbian.

    1. Download Raspbian Stretch with Desktop (the .zip file).

    2. Extract the Raspbian image to a folder on your computer.

  2. Install Raspbian to the microSD card.

    1. Download and install the Etcher SD card burner utility.

    2. Run Etcher and select the Raspbian image that you extracted in step 1.

    3. Select the microSD card drive. Note that Etcher may have already selected the correct drive.

    4. Click Flash to install Raspbian to the microSD card.

    5. Remove the microSD card from your computer when installation is complete. It's safe to remove the microSD card directly because Etcher automatically ejects or unmounts the microSD card upon completion.

    6. Insert the microSD card into Pi.

Enable SSH and SPI

  1. Connect Pi to the monitor, keyboard and mouse, start Pi and then sign in to Raspbian by using pi as the user name and raspberry as the password.

  2. Click the Raspberry icon > Preferences > Raspberry Pi Configuration.

    The Raspbian Preferences menu

  3. On the Interfaces tab, set SPI and SSH to Enable, and then click OK. If you don't have physical sensors and want to use simulated sensor data, this step is optional.

    Enable SPI and SSH on Raspberry Pi

Note

To enable SSH and SPI, you can find more reference documents on raspberrypi.org and RASPI-CONFIG.

Connect the sensor to Pi

Use the breadboard and jumper wires to connect an LED and a BME280 to Pi as follows. If you don’t have the sensor, skip this section.

The Raspberry Pi and sensor connection

The BME280 sensor can collect temperature and humidity data. And the LED will blink if there is a communication between device and the cloud.

For sensor pins, use the following wiring:

Start (Sensor & LED) End (Board) Cable Color
LED VDD (Pin 5G) GPIO 4 (Pin 7) White cable
LED GND (Pin 6G) GND (Pin 6) Black cable
VDD (Pin 18F) 3.3V PWR (Pin 17) White cable
GND (Pin 20F) GND (Pin 20) Black cable
SCK (Pin 21F) SPI0 SCLK (Pin 23) Orange cable
SDO (Pin 22F) SPI0 MISO (Pin 21) Yellow cable
SDI (Pin 23F) SPI0 MOSI (Pin 19) Green cable
CS (Pin 24F) SPI0 CS (Pin 24) Blue cable

Click to view Raspberry Pi 2 & 3 Pin mappings for your reference.

After you've successfully connected BME280 to your Raspberry Pi, it should be like below image.

Connected Pi and BME280

Connect Pi to the network

Turn on Pi by using the micro USB cable and the power supply. Use the Ethernet cable to connect Pi to your wired network or follow the instructions from the Raspberry Pi Foundation to connect Pi to your wireless network. After your Pi has been successfully connected to the network, you need to take a note of the IP address of your Pi.

Connected to wired network

Run a sample application on Pi

Sign into your Raspberry Pi

  1. Use one of the following SSH clients from your host computer to connect to your Raspberry Pi.

    Windows Users

    1. Download and install PuTTY for Windows.
    2. Copy the IP address of your Pi into the Host name (or IP address) section and select SSH as the connection type.

    PuTTy

    Mac and Ubuntu Users

    Use the built-in SSH client on Ubuntu or macOS. You might need to run ssh pi@<ip address of pi> to connect Pi via SSH.

    Note

    The default username is pi , and the password is raspberry.

Configure the sample application

  1. Clone the sample application by running the following command:

    sudo apt-get install git-core
    git clone https://github.com/Azure-Samples/iot-hub-c-raspberrypi-client-app.git
    
  2. Run setup script:

    cd ./iot-hub-c-raspberrypi-client-app
    sudo chmod u+x setup.sh
    sudo ./setup.sh
    

    Note

    If you don't have a physical BME280, you can use '--simulated-data' as command line parameter to simulate temperature&humidity data. sudo ./setup.sh --simulated-data

Build and run the sample application

  1. Build the sample application by running the following command:

    cmake . && make
    

    Build output

  2. Run the sample application by running the following command:

    sudo ./app '<DEVICE CONNECTION STRING>'
    

    Note

    Make sure you copy-paste the device connection string into the single quotes.

You should see the following output that shows the sensor data and the messages that are sent to your IoT hub.

Output - sensor data sent from Raspberry Pi to your IoT hub

Read the messages received by your hub

One way to monitor messages received by your IoT hub from your device is to use the Azure IoT Tools for Visual Studio Code. To learn more, see Use Azure IoT Tools for Visual Studio Code to send and receive messages between your device and IoT Hub.

For more ways to process data sent by your device, continue on to the next section.

Next steps

You’ve run a sample application to collect sensor data and send it to your IoT hub.

To continue to get started with Azure IoT Hub and to explore all extended IoT scenarios, see the following: