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    Introduction of Amazon AWS IoT

    Amazon AWS IoT is a cloud IoT service platform that enables you to connect devices to AWS Services and other devices, secure data and interactions, process and act upon device data, and enable applications to interact with devices even when they are offline. (https://aws.amazon.com/iot/how-it-works/)

    The service architecture of AWS IoT:

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    (Picture from http://docs.aws.amazon.com/iot/latest/developerguide/aws-iot-how-it-works.html )


    In the architecture, Ameba belongs to the upper-left “Things” block. A TLS secure channel will be established between “Things” and the MQTT Message Broker. Afterward, “Things” and “Message Broker” communicate using MQTT Protocol via this secure channel. Behind the “Message Broker”, the “Thing Shadows” keeps messages temporarily when Ameba is offline and sends the control message to Ameba the next time it is connected. The “Rules Engine” allows you to place restrictions on the behavior of Things or to connect Things to other services of Amazon.

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    Setup AWS Management Console

    First, create an account and sign up for AWS IoT service: https://aws.amazon.com/ 

    Afterwards, log in to the Amazon Management Console and click “IoT Core” found under services -> Internet of Things.

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    Then you will enter the homepage of AWS IoT. To offer the best service quality, Amazon offers servers in different regions for users to choose from. Click the region dropdown menu at the upper-right:

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    Choose a nearby region.

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    Then from Services, go to Onboard then Get Started.

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    Enter the main page of AWS IoT. Under the Onboard a device, click Get started.

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    Click Create single thing.

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    Fill in “ameba” on the name field. Attributes represent the status of Ameba.

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    Under the searchable thing attributes. The value of the attributes can be updated directly by Ameba or by the control side and control side can request Ameba to set the attribute to desired value. Here we add an attribute named “led” with value “0” and click “Next”.

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    Click Skip creating a certificate at this time and then Create thing

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    Next, click Policy¸ and create a policy. The policy is used to restrict the functions that a “thing” can do, it can limit the MQTT actions or specific topics that can be performed. Learn more about policy:

    http://docs.aws.amazon.com/iot/latest/developerguide/authorization.html

    Here we do not place policy on Ameba. Fill in “amebaPolicy” in the Name field, “iot:*” in Action field and “*” in resources field. Then “Allow”. Finally, click “Create”.

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    Next, we have to setup the TLS certificate. You can choose to user-defined or generate a certificate by AWS IoT. In this example we click Create Certificate to generate a TLS certificate.

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    You can see 4 Links. Please download each of the link, “public key”, “private key”, “Certificate” and “rootCA”. After downloading the 4 files, click Done and go back to the certificate main page.

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    Click Attach a policy in the Actions dropdown menu.

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    Choose amebaPolicy and click attach.

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    Then go back to the Actions drop down menu at the top right of the certificate homepage, click on Attach thing, select the thing “ameba” you just created when the window below appears, then click on Attach.

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    Go back to certificate main page and click Certificate and click Activate in the Actions drop down menu.

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    Next, click Manage, and click Things, then click “ameba” the thing we created just now. Click on Interact and View settings.

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    Find out the information of Rest API Endpoint to set Amazon Alexa: — REST API endpoint: In the value “https://a1a7oo4baosgyy.iot.us-east-1.amazonaws.com/things/ameba/shadow”, the part “a1a7oo4baosgyy.iot.us-east-1.amazonaws.com” is the MQTT Broker server address. — MQTT topic： The value “$aws/things/ameba/shadow/update” represents the MQTT topic we will use in the AWS IoT Shadow service (if we use MQTT only, without AWS IoT Shadow service, then we can specify other topic names). It is recommended to use “$aws/things/ameba/shadow/update” here.

    Ameba setting

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    Setup Realtek AMB21/22/23 Dev Board

    Open “File” -> “Examples” -> “AmebaMQTTClient” -> “Amazon_AWS_IoT_Basic”

    In the sample code, modify the highlighted snippet to reflect your WiFi network settings. 1

    Then, fill in the Thing_Name as “ameba”.

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    And the MQTT broker server address we found earlier in AWS IoT.

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    Next, fill in the rootCA used in TLS. Download and make sure the downloaded rootCA contents conforms to the rootCA used in the sketch.

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    Next, fill in the certificate we created in the AWS IoT Console (i.e., client certificate), usually, its file name ends with “-certificate.pem.crt” (e.g., “efae24a533-certificate.pem.crt”). Open the certificate with a text editor, and adjust its format as follows to use in the sketch: – Add the new line character “\n” at the end of each line. – Add a double-quote at the beginning and the end of each line. – To concatenate each line as a string, add “\” at the end of each line. – The last line ends with a semicolon. Adjust the format of the private key in the same way and add it to privateKeyBuff.

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