Lab 2 - Interract with a Thing

It’s the summer, and its hot outside. Lets play around with remote controlled Air Conditioning units.

For this lab, our M5StickC will act as our Air Conditioning unit.

You can turn the AirCon ON or OFF remotely as well as set a target temperature.

  • If the AirCon is OFF, the temperature will rise to a stable 40 deg celcius.
  • If the AirCon is ON, the temperature will decrease to reach your chosen temperature

M5StickC Lab2

Configuration

In order to configure the code and your M5StickC for Lab1, you must change the following lines of code:

In file: ~/environment/workshop/include/lab_config.h

Replace:
#define LABCONFIG_LAB1_AWS_IOT_BUTTON

With:
#define LABCONFIG_LAB2_SHADOW

Rebuild Code

cd ~/environment/workshop
cmake --build build

Flash Code

Please follow the same procedure from Flash the firmware files.

Result

Log into your AWS IoT Management console. Select your Thing (MyThing), and select Shadow.

  1. If the device has successfully run the demo code, it should have reported it’s first shadow document:
{
	"reported": {
		"powerOn": 0,
		"temperature": 40
	}
}
  1. Edit this shadow document, on the page with the following:
{
	"desired": {
		"powerOn": 1,
		"temperature": 22
	}
}

Note: For the purpose of the demo, powerOn parameter is used to toggle turning ON or OFF the simulated Air Conditioning unit, and desired.temperature is used to set the desired temperature value.

Modifying the shadow desired document, should instantly result in a compiled shadow document looking something like:

{
	"desired": {
		"powerOn": 1,
		"temperature": 22
	},
	"reported": {
		"powerOn": 0,
		"temperature": 40
	},
	"delta": {
		"powerOn": 1,
		"temperature": 22
	}
}

Now that the Air Con is turned ON, watch how first of all, the device will report turning itself ON and how it’s temperature will decrease to meet your set value.

Note: Be carefull when setting the desired.temperature value. The lab code only supports positive integer values. Do not use a floating point value.

Done

You are done with Lab 2.

Challenge

  • Can you modify the code to control the device’s LED via the thing shadow?
  • Can you plug the M5StickC into your actual Air Conditioning and control it’s on/off and temperature states? (if so, send us a picture!)