1. Concept

Sensor outlier detection alarm.
Set to receive a notification when the value sent from the sensor exceeds the set threshold.
The IoT core receives the MQTT message sent from W5100S-EVB-Pico, sets a rule, and sends outlier data to SNS to receive email notifications.
 

2. Implementation

1) Connect AWS IoT Core + W5100S-EVB-Pico

Create Thing

• Click "Create things" 

• Select "Create single thing" 

• The thing name is set to be identifiable.

• Select Automatically generate certificate.

• Create and connect policies for IoT Core use.
• The policy details are as follows.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iot:Connect",
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": "iot:Publish",
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": "iot:Receive",
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": "iot:Subscribe",
      "Resource": "*"
    }
  ]
}

Publish MQTT Message

• We used the SDK that connects RP2040 and AWS, and can be used by following the GitHub link .
• I changed the thing name to the thing name created above.

/* AWS IoT */
#define MQTT_DOMAIN "account-specific-prefix-ats.iot.ap-northeast-2.amazonaws.com"
#define MQTT_PUB_TOPIC "$aws/things/YOUR_THING_NAME/shadow/update"
#define MQTT_SUB_TOPIC "$aws/things/YOUR_THING_NAME/shadow/update/accepted"
#define MQTT_USERNAME NULL
#define MQTT_PASSWORD NULL
#define MQTT_CLIENT_ID "YOUR_THING_NAME"

• The message payload currently being sent by W5100S-EVB-Pico is as follows:

{"temperature":23, "humidity":25}

2) SNS settings

Create Topic

• In the AWS SNS Console window, click Topics > Create topic.
   

• Select Standard as the Type and set the Name of the Topic.
• FIFO supports only SQS subscription protocol.
   

Create Subscriptions

• Go to the details page of the topic you created and select create subscription.
   

• Subscription is where you will receive notifications, and the endpoint is set to email.
• Confirmation is required after creation.
   

• After creation, a verify email is sent to the corresponding email address. It can be used only after confirmation via email.
• Go to your email and click Confirm subscription
   

• When you click, the screen below will appear, and when you enter Subscription on SNS, the status of the subscription will change to Confirmed.
   

Test SNS

• Go to topic and click Publish message
   

• Enter test message in messgae body and click publish message.
   

• You can confirm that a test message has been sent to your email.
   

3) Creation of IoT Core Rule

• Select Message Routing > Rules > Create rule in AWS IoT
• Set rule name
   

• Enter SQL statement. The format is
• SELECT FROM WHERE
• Triggered when the temperature value is 1 (specific value) or higher.
   

• Select SNS from rule actions and select the TOPIC you created.
• Create a new role, or select a previously used role.
   

4) Test

• Since Pico is connected, if you activate the rule created in IoT Core,
• When the conditions are met, a notification is sent to the subscription you have set.