Reading A Sensor

Begin by learning the basics of programming Electric Imp applications. We will use the Electric Imp HTS221 library to take temperature and humidity readings from a sensor. We will also use the Initial State library to send the data we collect from the sensor to a cloud service.

This code can be easily configured for use with an impExplorer™ Developer Kit, impAccelerator™ Battery Powered Sensor Node or impC001 Breakout Board.

Skill Level

Beginner

This example will focus on writing Squirrel code. If you have not already done so, please visit the Getting Started Guide to learn how to configure your device with BlinkUp™ and how to use the Electric Imp IDE, impCentral™.

What You Learn

• How to use Electric Imp libraries.
• How to configure a device’s sensor and take synchronous readings.
• How to exchange data between device and agent.
• How to send data to a cloud service such as Initial State.

What You Need

• Your 2.4GHz 802.11bgn WiFi network name (SSID) and password (not needed if you are using the impC001).
• A computer with a web browser.
• A smartphone with the Electric Imp app (iOS or Android) installed.
• A free Electric Imp Developer Account.
• A free Initial State Account.
• An HTS221 temperature/humidity sensor wired to an imp-enabled device. The products listed below have all the hardware required for this example:
  • impExplorer Developer Kit
  • impAccelerator Battery Powered Sensor Node
  • impC001 Cellular Breakout Board.

Instructions

• Activate your device with BlinkUp.
• Log into impCentral.
• Create a new Product and Development Device Group.
• Copy and paste the Device Code into the Device Code pane in the impCentral code editor.
• Enter the i2c hardware object for your device into the i2c variable on line 32.
• Copy and paste the Agent Code into the Agent Code pane in the impCentral code editor.
• Sign into Initial State.
• Find your Streaming Access Key on the My Account page.
• Navigate back to impCentral.
• In the Agent Code, enter your Initial State Streaming Access Key into the STREAMING_ACCESS_KEY constant on line 19.
• Hit the Build and Force Restart button to start the code.
• Note the agent ID in the logs.
• Navigate back to Initial State, find the Bucket that matches your agent ID.
• Watch your data update in the Source, Lines, Waves, and Tile views on the Initial State website.

Code

Device Code

Agent Code

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