Connecting Raspberry Pi with Sense HAT to Azure IoT Hub Using Node-RED

Following up with A Simulated IoT Device with Node-RED, I replaced the simulated device with a Raspberry Pi with Sense HAT.

Node-RED Flow

The flow is much similar to that of a simulated device with as shown below,

image

where

  • I initialize temperature, humidity and pressure as global variables and each is set to 0.
  • In the sensehat function, load the ambient data from Sense HAT, use mathjs to round the output to 2 decimal points and update the global variables with the rounded values before sending the data to Azure IoT Hub. Here I include the device connection string in the payload.
  • For the dashboard, the gauges and the charts are reading the data from the global variables. I noticed the Sense HAT temperature reading is generally about 10 degree Celsius higher than my room temperature.

Dashboard

Other than the ranges of data and minor cosmetic changes, the settings are the same with what I used with a simulated device. Here’s a snapshot.

image

Next Step: Azure IoT Edge

Introduce Azure IoT Edge in opaque mode and connect the Raspberry Pi as an isolated device from Azure IoT Hub. Should be interesting. Stay tuned.

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