Securely stream data from ESP8266 MCUs to Azure IoT Hub or Azure IoT Central
|Author||Dave Glover, Microsoft Cloud Developer Advocate|
|Solution||This solution securely streams sensor data directly to Azure IoT Hub over HTTPS calling Azure REST APIs from an ESP8266 MCU.|
|Source Code||ESP8266 Secure Azure IoT Hub Client V2|
|Platform||ESP8266 (Firmware V2.3.0), Azure IoT Central, Azure IoT Hub, Azure Stream Analytics, Power Bi|
|Video Training||What is Azure IoT Central, Introduction to Azure IoT Hub|
|Screencasts||How to create the Azure IoT Central Application, How to create an Azure IoT Hub|
|Date||As at Nov 2018|
|Acknowledgment||Thanks to Štěpán Bechynský "[Proof of Concept – NodeMCU, Arduino and Azure Event Hub] (https://microsoft.hackster.io/en-US/stepanb/proof-of-concept-nodemcu-arduino-and-azure-event-hub-a33043)" project|
This project is implemented and tested on the following ESP8266 based development boards:
IoT Hub Certificate Verification
This sample verifies your IoT Hub Server Certificate to mitigate against Man in the Middle Attacks.
The Server Certificate Fingerprint was generated as follows:-
- From Bash on Ubuntu on Windows (10) or Linux
- echo -n | openssl s_client -connect IoTCampAU.azure-devices.net:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > cert.pem
- openssl x509 -noout -in cert.pem -fingerprint
- See Certificate Pinning article for more information
Azure IoT Hub
IoT Hub is designed to "Securely connect, monitor, and control millions of IoT assets" and is designed for internet scale data ingestion.
For more background information read this "Stream Analytics & Power BI: A real-time analytics dashboard for streaming data" article.
Setup and Deployment Summary
- Setup your Azure IoT Hub. There is a free 8000 message a day subscription to get started.
- Register your device with Azure IoT Hub.
- Update the main AzureClient.ino sketch
- Deploy the solution to your ESP8266 based device.
- View data with Device Explorer
- Optionally: Visualise your data in real time with Azure Stream Analytics and Power BI.
Setting Up Azure IoT Hub
Follow lab Setting Up Azure IoT to provision an Azure IoT Hub and an IoT Hub device.
Open the Config.h file in the solution and configure the following:
#define WIFI_SSID "[Your WiFi SSID]" #define WIFI_PWD "[Your WiFi Password]" #define NTP_SERVER "au.pool.ntp.org" #define DEVICE_LOCATION "[Your device location - eg Garage]" #define DEEP_SLEEP_IN_SECONDS 0 #define PUBLISH_RATE_IN_SECONDS 60 #define IOTHUB_CONNECTION_STRING "[Your IoT Hub/Central Connection String eg HostName=saas-iothub-897898-f33a-4002-a44a-7ca5961b00b6.azure-devices.net;DeviceId=wemos-garage;SharedAccessKey=uRsr78d56s87878dd89d675g88H8+nRoiVgc3+epqlMHHg="
The sample includes the following sensors in the main project: Fake Sensor, BME280, and the Sht30. The default sensor returns fake temperature, humidity, pressure and light telemetry. To switch to a real sensor comment out the Sensor sensor line and uncomment one of real sensors.
// uncomment required sensor Sensor sensor; // Fake sample environmental data useful for testing/// //Bme280 sensor; //Sht30 sensor;/
There are additional drivers in the drivers directory: BMP180, BMP280, DHT11, DHT22, LDR, OLED.
From Device Explorer, head to the Data tab, select your device, enable consumer group then click Monitor.
Azure Stream Analytics
Azure Stream Analytics enables you to gain real-time insights in to your device, sensor, infrastructure, and application data.
See the Visualizing IoT Data lab. Replace the query in that lab with the following and be sure to change the time zone to your local time zone offset. Australia (AEDST) is currently +11 hours.
SELECT iothub.connectiondeviceid deviceid, Geo AS GeoLocation, Max(DateAdd(Hour, 10, EventEnqueuedUtcTime)) AS TimeCreated, -- AU EST UTC + 10 Avg(Celsius) AS Temperature, AVG(Humidity) AS Humidity, AVG(Light) AS Light, AVG(HPa) AS AirPressure INTO [PowerBI] FROM [TelemetryHUB] TIMESTAMP BY EventEnqueuedUtcTime GROUP BY iothub.connectiondeviceid, Geo, TumblingWindow(minute, 30)
Microsoft Power BI makes it easy to visualise, organize and better understand your data.
Follow the notes in the See the Visualizing IoT Data lab and modify the real time report as per this image.
Power BI Designer Setup
Power BI Report Viewer
View on the web or with the Power BI apps available on iOS, Android and Windows.
The AzureClient sketch streams data in the following JSON format, of course you can change this:)
ESP8266 Based Development Boards
There are a number of ESP8266 based development boards available so be sure to check out this great article "Comparison of ESP8266 NodeMCU development boards".
NodeMCU V2 with BMP180 Sensor
- NodeMCU v2
- BMP180 Barometric Pressure Sensor
- 1 x 400 Tie Point Interlocking Solderless Breadboard
WeMos D1 Mini MCU
WeMos D1 Mini with BMP180 Sensor
WeMos D1 Mini with DHT Shield Sensor
No wiring required, just solder the supplied header pins for the WeMos and the DHT Sensor shield.
- NodeMCU - On Windows, Mac and Linux you will need to install the latest CP210x USB to UART Bridge VCP Drivers.
- WeMos - On Windows and Mac install the latest Ch340G drivers. No drivers required for Linux.
- ESP8266 Thing Development Board Hookup Guide
As at November Jan 2018 use:-
- Arduino IDE 1.8.7.
- ESP8266 Board Manager 2.3.0 for HTTPS/TLS Secure Client support.
Arduino Boards Manager ESP8266 Support
Arduino version 1.6.4 and above allows installation of third-party platform packages using Boards Manager.
- Install Arduino 1.8.7 from the Arduino website.
- Start Arduino and open Preferences window.
- Enter http://arduino.esp8266.com/stable/package_esp8266com_index.json into Additional Board Manager URLs field. You can add multiple URLs, separating them with commas.
- Open Boards Manager from Tools > Board menu and install esp8266 platform (and don't forget to select your ESP8266 board from Tools > Board menu after installation).
- Select NodeMCU or WeMos D1 Mini Board: Tools -> Board -> NodeMCU 1.0 (ESP-12E module) or WeMos D1 Mini
- Set Port and Upload Speed: Tools. Note, you may need to try different port speeds to successfully flash the device. Faster is better as each time you upload the code to your device you are re-flashing the complete ROM not just your code.
ESP8266 Arduino Core Documentation
Be sure to read the ESP8266 Arduino Core Documentation - there are some minor gotchas.