Activity No. 2: Measure the humidity and display the value in the serial console (IoT sensors kit)

 The humidity sensor of the NUCLEO-IKS01A3 is a module that measures the humidity of the ambient air over a range of 0 to 100%.
At 0% the air is dry, at 100% the humidity (water in suspension condenses) forms droplets, it is fog. 

The operating principle is simple. This MEMS (micro-electro-mechanical systems) sensor is made of a polymer capable of detecting variations in humidity. The information returned by the sensor is the percentage value.

To measure the humidity using the NUCLEO-L476RG card, the following connection must be made: 
- Connect the NUCLEO-IKS01A3 to the connectors on the card. 
- Connect the L476RG board to the computer using the mini-usb cable

Let's move on to programming now! 

We are going to use two blocks:
- "write in the console", available in the Communication of the block locker to manage the display.
- "[HTS221 hygrometer] relative humidity", available in the Sensors, to retrieve the value of the module.



Use the following interface to program the module: 


The humidity will be displayed in the console, at the bottom of the interface.




To facilitate reading, a pause of 1 second can be inserted.
 


Once the program has been created, it must be copied onto the card. To do this, use the "Upload" button (see Activity 0: Getting started with the board)

We are now going to create a text, to make it easier for the user to read, in particular by adding the symbol %

You must use the block "create the text ... ... ... " available in the Text part of the block locker, by combining it with the block ("...") which allows you to write. 



Here is an example of ready-to-use code:


This code includes:
- the display of a text consisting of the humidity value + the acronym %, in the console
- a 1 second pause to facilitate reading

Download the program to the card and launch the console to view the air humidity. 


You succeeded ? Perfect, you now know how to program the temperature sensor using your NUCLEO-L476RG board! 
Discover the other activities of the IoT Sensors kit by clicking on the icons below.