Applications

Connecting the ADICUP3029 to the Medium One IoT Cloud

blue light on a black horizon with ones and zeros floating with cloud symbols in the sky

By Greg Toth for Mouser Electronics

The Analog Devices^® EVAL-ADICUP3029 is an IoT development platform featuring an ultra-low power Arm^® Cortex^®-M3 based mixed-signal microcontroller, Bluetooth^® and Wi-Fi connectivity, and expansion headers for Arduino^® and Pmod^™ add-on boards. The Medium One IoT Prototyping Sandbox is a cloud-based IoT platform designed to help early stage developers prototype IoT projects or connect existing hardware to the cloud. In this project we’ll set up an IoT development environment using the ADICUP3029 to read a hardware sensor and send the data to the Medium One cloud using MQTT. Once the data is in Medium One, it can be processed and viewed using programmable workflows and configurable widget dashboards.

Project Materials and Resources

The project BOM lists components used in this project. Additional hardware and software development tools are also identified.

Project BOM

Analog Devices EVAL-ADICUP3029 Development Platform
Analog Devices EVAL-ADT7420-PMDZ temperature sensor
Medium One IoT Prototyping Sandbox subscription

Hardware

11 b/g/n Wi-Fi access point with a DHCP server, Internet connectivity, and without a firewall or proxy that blocks outgoing traffic to the Internet
Personal computer (PC) running Windows^®

Accounts and Software

Web browser for accessing software download sites and Medium One IoT Prototyping Sandbox
Login account for the Medium One IoT Prototyping Sandbox
Analog Devices CrossCore^® Embedded Studio^™ integrated development environment (IDE)
Application project files available in a GitHub repository here
Wi-Fi access point connection details including SSID and password

Project Technology Overview

Analog Devices EVAL-ADICUP3029

The ADICUP3029 (Figure 1) is an Arduino-like development platform based on the ADuCM302x family of ultra-low power, integrated mixed-signal microcontroller systems for processing, control and connectivity. It offers Bluetooth and Wi-Fi connectivity options for creating Internet of Things (IoT) applications that communicate wirelessly with other systems and devices. The combination of board, microcontroller and onboard components offer developers:

ADuCM3029 32-bit ARM Cortex-M3 microcontroller
256kB flash memory
64kB SRAM memory
Wi-Fi connectivity
Bluetooth 5.0 connectivity
Multiple analog and digital input/outputs
Serial UART
I²C
Multiple SPI buses
Onboard Serial Wire Debug (SWD) port for programming and debugging application code through a USB cable; can also provide a virtual serial port connection to the ADuCM3029
Two onboard LEDs
Arduino Uno Rev3 compatible connectors
4-pin I2C Grove I/O connector
I2C and SPI PMOD I/O connectors
Battery holder
DC power jack accepting 7V to 12V DC supply voltage

Technical documentation on the ADICUP3029 can be found here and here.

Figure 1: EVAL-ADICUP3029 Development Board (Source: Mouser Electronics)

Analog Devices EVAL-ADT7420-PMDZ Temperature Sensor

The EVAL-ADT7420-PMDZ (Figure 2) is a high-accuracy digital temperature sensor that can interface to the ADICUP3029 through its I2C PMOD connector. In can measure temperature in degrees Celsius with an accuracy of +/- 0.25°C and is rated for operation over -40°C to 150°C temperature range.

Figure 2: EVAL-ADT7420-PMDZ Temperature Sensor (Source: Mouser Electronics)

Technical documentation on the EVAL-ADT7420-PMDZ can be found here and here.

Analog Devices CrossCore Embedded Studio

Firmware programs that run on microcontrollers are typically developed and tested using an integrated development environment (IDE) running on a personal computer. The IDE provides an editor, compiler, linker, debugger, and a mechanism for transferring binary program images to the microcontroller.

The ADICUP3029 can be programmed using Analog Devices CrossCore Embedded Studio, an Eclipse-based IDE that runs on Windows and Linux computers. It connects to the ADICUP3029 using a USB cable that supports programming and debugging. CrossCore Embedded Studio can be downloaded for free from the CrossCore Embedded Studio site.

Project Application Source Code Files

For this project CrossCore Embedded Studio was used to create an initial set of project source code files that have been modified and extended to work with the Medium One IoT Prototyping Sandbox. The resulting files have been put in a GitHub repository that you can download and use for this project. The project files will be imported into the CrossCore Embedded Studio IDE where they’ll be compiled and downloaded to the ADICUP3029 board. The project files consist of a main application program and supporting functions for MQTT and I/O processing.

Medium One IoT Prototyping Sandbox

The Medium One IoT Prototyping Sandbox (Figure 3) is designed to help early-stage developers prototype their IoT project or connect their existing hardware to the cloud. It offers an IoT Data Intelligence platform enabling customers to quickly build IoT applications with less effort. Programmable workflows allow you to quickly build processing logic without having to create your own complex software stack. Configurable dashboards allow you to visualize application data and view real-time data in a variety of formats. Medium One’s iOS and Android apps allow you to build simple mobile app dashboards that can communicate with your devices through the IoT Prototyping Sandbox.

Figure 3: Medium One IoT Prototyping Sandbox (Source: Mouser Electronics)

IoT devices can exchange data with Medium One through either a REST API or MQTT. More detailed information about the Medium One IoT Prototyping Sandbox can be found here and on the Medium One site.

The Setup (Hardware)

While setting up the hardware, be sure to remember that electronic components are static-sensitive so handle accordingly.

Personal Computer (PC)

Power up the personal computer and allow it to boot up.

Wi-Fi Access Point

Make sure your Wi-Fi access point is running with an active connection to the Internet and a DHCP server that assigns IP addresses. You’ll need to know the access point SSID, security type, and security credentials to be used later when configuring the board’s Wi-Fi module.

ADICUP3029 and EVAL-ADT7420-PMDZ

Unbox the ADICUP3029 board and Wi-Fi module and connect them together as described in the ADICUP User Guide found here.

Connect the EVAL-ADT7420-PMDZ temperature sensor to the ADICUP3029 8-pin PMOD connector (P9), making sure to match up the pin numbers correctly. The S2 UART switch should be in the WI-FI position and the S5 POWER switch should be in the WALL/USB position.

Connect the ADICUP3029 board to the PC using the USB cable. You can verify your connection by checking to see if a “DAPLINK” drive is displayed in on your local devices and drives list.

The Setup (Software)

Download and Install CrossCore Embedded Studio (CCES)

Download and install CrossCore Embedded Studio on your PC by following the instructions in the EVAL-ADICUP3029 User Guide and CrossCore Embedded Studio Quickstart User Guide. Use the registration Serial Number printed on the card included in the ADICUP3029 box. Be sure to install the Device Family Pack, Board Support Pack, Sensor Software Pack and Wi-Fi Software Pack as described in the CCES Quickstart Guide. You can run the blink_example program to verify your hardware and software is working.

Download and Import the Project Application Source Code Files

Web browse to the GitHub repository and find the ADuCM3029_ MediumOne_1.0.0.zip file. Click the .zip file, then click Download to download it to your computer.

In CCES select File > Import… > General > Existing Projects into Workspace and click Next. Checkmark Select archive file and click Browse to pick the .zip file you downloaded from GitHub. Make sure the ADuCM3029_MediumOne project is checkmarked and click Finish. After completing the import, the Project Explorer tab should look like Figure 4.

Figure 4: After Importing the Project Source Code Files into CrossCore Embedded Studio (Source: Mouser Electronics)

We’ll come back to the source code files after setting up Medium One.

Set Up the Medium One IoT Prototyping Sandbox

Web browse to the Medium One IoT Prototyping Sandbox and log in, after which you should see an initial dashboard resembling Figure 3. Click Setup > Manage Users > Add New User. Set Username to mydevice, create a password of your choosing and enter it in both password fields, then click Save. In the Manage API Users list you should see a new user account having Login ID = mydevice and an auto-generated user MQTT ID like Figure 5.

Figure 5: Newly Created User ID With Auto-Generated MQTT ID (Source: Mouser Electronics)

Click Setup > MQTT and you should see a Project MQTT ID and a set of port numbers like Figure 6.

Figure 6: Project MQTT ID (Source: Mouser Electronics)

Medium One uses MQTT usernames and passwords for authentication. The MQTT username is created by combining the Project MQTT ID, a forward slash, and the user MQTT ID. For example, if the Project MQTT ID is “ZHxxxxxxx0Y” and the user MQTT ID is “sTxxxxxxx8w” the corresponding MQTT username would be “ZHxxxxxxx0Y/sTxxxxxxx8w”.

Next, we’ll create the MQTT password. Navigate to Setup > Manage API Keys > Add New API Key. Set the description to mydevice, make sure Enabled is checkmarked, and click Save. The result should look like Figure 7.

Figure 7: Newly Created API Key (Source: Mouser Electronics)

The MQTT password is created by combining the API Key, a forward slash, and the mydevice user password. For example, if the API Key is “PZxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxMBQ” and the mydevice user password is “AaaaBbbb3” the corresponding MQTT password would be “PZxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxMBQ/AaaaBbbb3”.

The MQTT topic has the following format: “0/Project MQTT ID/User MQTT ID/Device ID”.

The Device ID field can be anything and we’ll use “mydevice” as the Device ID. For example, if the Project MQTT ID is “ZHxxxxxxx0Y” and the user MQTT ID is “sTxxxxxxx8w” the corresponding MQTT topic would be “0/ZHxxxxxxx0Y/sTxxxxxxx8w/mydevice”.

The MQTT username, MQTT password and MQTT topic strings will get added to the project source code in the next step.

Update Application Source Code Files for Medium One Account Parameters

Set Wi-Fi Connection Parameters

Open project file src/ADuCM3029_MediumOne.h in the editor. Find these variables and set them to your own Wi-Fi SSID and password strings:

aWifiSSID
aWifiPassword

Set Medium One Connection Parameters

In the same src/ADuCM3029_MediumOne.h file, find these variables and set them to your own Medium One MQTT parameter strings as described earlier:

aMQTTTopicName
aMQTTUsername
aMQTTPassword

*** NOTE *** The ADI-WifiSoftware CMSIS Pack (version 1.0.1) is not able to connect to the Medium One MQTT broker over TLS and this project uses unencrypted MQTT communications between the ADICUP3029 and Medium One MQTT broker. The MQTT username and password are sent over the Internet in the clear and neither the credentials nor the sensor data are encrypted.

Save the modified file and then build the project. Verify the code compiles without errors. If you see compilation errors, check the changes you made to src/ADuCM3029_MediumOne.h.

Run the Application

Make sure the ADICUP3029 board is connected to the PC through USB. Set up a debug configuration as described in the CCES Quickstart User Guide and then run the program under the debugger. The program should be downloaded to the board and the debugger should stop on the first line of the main() function. Use menu command Run > Resume to start program execution. Monitor the CCES Console tab for messages about the program starting, connecting to Wi-Fi, and transmitting data to Medium One.

How the Application Program Works

This program is derived from the Analog Devices ADuCM3029_IBMWatson_Greenhouse example application with the following changes and enhancements:

Interface with the EVAL-ADT7420-PMDZ temperature sensor
Remove unused I/O functions
Connect to the Medium One MQTT broker
Periodically read the temperature sensor
Add timestamp and loop count data elements
Generate a JSON formatted MQTT payload message and send to Medium One MQTT broker

MQTT Payload Format

MQTT messages are formatted as JSON strings according to the Medium One MQTT payload specification. Here's an example message.

{"event_data":{"tempf":77.89999389648438,"timestamp":19193,"iteration":1}}

Fields:

tempf = temperature in degrees Fahrenheit
timestamp = board tick clock
iteration = application loop counter

Try heating or cooling the temperature sensor to see the data values change.

View Data in the Medium One Dashboard

In the Medium One dashboard navigate to Data Viewer > Data Streams and click raw Events. You should see raw messages (Figure 8) being received from the ADICUP3029. Click the “+” sign to view message details.

Figure 8: Raw Message Display (Source: Mouser Electronics)

Click Dashboard on the top left, then click Add Widget > Single User Real Time Events Stream to add an event stream widget to the dashboard.

In the Select user dropdown, select mydevice. You should now see messages appearing in the Real Time Events Stream widget (Figure 9). Click the save icon in the upper right corner to save your modified dashboard.

Figure 9: Real Time Events Stream Widget Display (Source: Mouser Electronics)

Add More Widgets

To display more widgets we need to enable specific data fields contained in the message payload. Navigate to Config > Data Streams and click on raw Events. The Schema Map should be pre-populated with fields detected in the incoming messages, however they are currently disabled. Check-mark the Active box on raw.iteration, raw.tempf, and raw.timestamp, then click Save Data Stream. These fields are now available for use in other dashboard widgets.

Back on the dashboard, click the Single User Last Value Table widget and select the mydevice user within the widget. Click the widget’s Tag Config icon to the right of the mydevice user selection and checkmark raw:iteration, raw:tempf, and raw:timestamp values, then click Save. The Last Value Table should now populate with the most recent received values for each field (Figure 10). Click the Save icon towards the upper right corner to save the updated dashboard.

Figure 10: Last Value Table Widget Display (Source: Mouser Electronics)

Now let’s add dashboard widgets for the temperature sensor and counters. Click Single User Real Time Gauge and select the mydevice user. Click the widget’s Tag Config icon and checkmark the raw:iteration, raw:tempf and raw:timestamp rows, then click Save. The updated dashboard should look like Figure 11. Click the dashboard save icon to save the updated dashboard. Try heating or cooling the temperature sensor to see the gauge values change.

Figure 11: Real Time Gauge Widgets Added to Dashboard (Source: Mouser Electronics)

At this point your ADICUP3029 board is running continuously, periodically reading the temperature and transmitting data measurements to the Medium One cloud. Remember to power off the ADICUP3029 board when you’re done, otherwise the board will continue to send messages to Medium One and consume daily message allotments.

Where to Go Next

This project created an end-to-end sensor-to-cloud application that sends real-time sensor data to the Medium One IoT Prototyping Sandbox. It can be modified and extended in a number of ways and here are a few examples:

Dive deeper into the application code and board hardware by reading the ADICUP3029 documentation and studying the source code
Add more widgets to the Medium One dashboard, such as a real-time line chart of temperature readings
Learn about the Medium One Workflow Studio, which lets you create data processing workflows to transform your sensor data
Experiment with the Medium One mobile apps
Implement bi-directional communications with the Medium One cloud
Modify the sensor data publishing interval by modifying the ADICUP3029 application source code
Connect other types of sensors to the ADICUP3029 board and include the data in MQTT messages
Enhance the MQTT communications to support MQTT over TLS

Don’t forget to let us know if you tried this project out for yourself. How well did the project work for you? Would you expand upon it? Have questions? If so, let us know on Facebook, Twitter, or LinkedIn.

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Greg is an architect, engineer and consultant with more than 30 years experience in sensors, embedded systems, IoT, telecommunications, enterprise systems, cloud computing, data analytics, and hardware/software/firmware development. He has a BS in Electrical Engineering from the Univ. of Notre Dame and a MS in Computer Engineering from the Univ. of Southern California.