# AWS IoT Core
Easily and securely connect devices to [**AWS IoT Core**](https://aws.amazon.com/iot-core/). AWS IoT Core uses MQTT to transmit and receive messages, a lightweight IoT messaging protocol. This tutorial explain how to set up AWS IoT Core and start sending IoT data from a Raspberry Pi connected over cellular.
### Quick Navigation
* [Create a Thing in AWS](#create-a-thing-in-aws)
* [Connect your device to AWS IoT Core](#connect-your-device-to-aws-iot-core)
* [Create your python script](#create-your-python-script)
### Prerequisites
* [AWS account](https://console.aws.amazon.com/)
* Monogoto SIM
* Raspberry Pi 3 or 4
## Create a Thing in AWS
Start by visiting the [**AWS portal**](https://console.aws.amazon.com/console/home)
Search for the **IoT Core** service
In the left side menu, navigate to **Manage > All devices > Things**
Click the button **Create Things** to create your digital Thing.
**Name your thing**, e.g. `mqtt-thing`
Select **Auto-generate a new certificate**
Attach an existing policy, or create a new one by clicking “**Create policy**”
When creating a new policy, add 4 statements allowing the Thing to **Connect**, **Publish**, **Receive** and **Subscribe**. Under Policy resource, add an asterisk `*` to allow all topic names to connect to AWS IoT Core.
```
Policy effect Policy action Policy resource
Allow iot:Connect *
Allow iot:Publish *
Allow iot:Receive *
Allow iot:Subscribe *
```
{% hint style="warning" %}
When using AWS IoT Core in production, restrict the Policy resource to specific topics to increase the security of your application.
{% endhint %}
#### **Download all keys and CA files**
Download and store the **Device certificate**, **Private key file** and **Amazon Root CA 1** in a directory called `certs`. Make sure to name the files properly as described in the table below.
| **Device certificate** | device.pem.crt |
| ---------------------- | ----------------- |
| **Private key file** | private.pem.key |
| **Amazon Root CA 1** | AmazonRootCA1.pem |
## Connect your device to AWS IoT Core
*This section explains how to run a python scrip on a Raspberry Pi, connected to Monogoto. For more information on how to connect the Raspberry Pi to Monogoto, see* [*this tutorial*](https://docs.monogoto.io/getting-started/general-device-configurations/raspberry-pi)*.*
**Access the Raspberry Pi** over ssh or by connecting a screen and keyboard
**Install the required libraries**
Before you install an AWS IoT Device SDK, run these commands in a terminal window on your Linux device to install the required libraries.
```bash
sudo apt-get install cmake
```
```bash
sudo apt-get install libssl-dev
```
Install the **AWS IoT Device SDK** for Python and download the sample apps to your device.
```bash
cd ~
pip3 install awsiotsdk
pip3 install AWSIoTPythonSDK
```
**Add certificates to the Raspberry Pi**
Add the **Device certificate**, **Private key file** and **Amazon Root CA 1** to a folder called `certs`.
```
cd ~
mkdir certs
```
{% hint style="info" %}
If you downloaded the certificates to a different machine, move the certificates to the RPI using the below command: `scp -r ~/certspi@:~/certs`
{% endhint %}
## Create your python script
#### Create a new file called `publish.py` containing the below script
{% code lineNumbers="true" %}
```python
# publish.py
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: MIT-0
import time as t
import json
import AWSIoTPythonSDK.MQTTLib as AWSIoTPyMQTT
# Define ENDPOINT, CLIENT_ID, PATH_TO_CERTIFICATE, PATH_TO_PRIVATE_KEY, PATH_TO_AMAZON_ROOT_CA_1, MESSAGE, TOPIC, and RANGE
ENDPOINT = ""
CLIENT_ID = "basicPubSub"
PATH_TO_CERTIFICATE = "/home/pi/certs/device.pem.crt"
PATH_TO_PRIVATE_KEY = "/home/pi/certs/private.pem.key"
PATH_TO_AMAZON_ROOT_CA_1 = "/home/pi/certs/AmazonRootCA1.pem"
MESSAGE = "hello world"
TOPIC = "device/RPI"
RANGE = 3
myAWSIoTMQTTClient = AWSIoTPyMQTT.AWSIoTMQTTClient(CLIENT_ID)
myAWSIoTMQTTClient.configureEndpoint(ENDPOINT, 8883)
myAWSIoTMQTTClient.configureCredentials(PATH_TO_AMAZON_ROOT_CA_1, PATH_TO_PRIVATE_KEY, PATH_TO_CERTIFICATE)
myAWSIoTMQTTClient.connect()
print('Begin Publish')
for i in range (RANGE):
data = "{} [{}]".format(MESSAGE, i+1)
message = {"message" : data}
myAWSIoTMQTTClient.publish(TOPIC, json.dumps(message), 1)
print("Published: '" + json.dumps(message) + "' to the topic: " + TOPIC)
t.sleep(0.1)
print('Publish End')
myAWSIoTMQTTClient.disconnect()
```
{% endcode %}
Replace `` with your **AWS endpoint** to the `publish.py` file (line 11)
{% hint style="info" %}
**To find your AWS endpoint**, go to the [AWS IoT console](https://console.aws.amazon.com/iot/home), near the bottom of the navigation pane, choose **Settings**.
In the **Settings** page you will find the **Endpoint**, which is unique to your AWS account and looks something like: `abcdef1234567-ats.iot.eu-west-1.amazonaws.com`.
{% endhint %}
In the AWS IoT Portal, open the **MQTT test client** and subscribe to the topic **device/RPI**
**Go back to your Raspberry Pi** and run the `publish.py` script using the command:
```bash
python3 publish.py
```
Expected response
```bash
Begin Publish
Published: '{"message": "hello world [1]"}' to the topic: device/data
Published: '{"message": "hello world [2]"}' to the topic: device/data
Published: '{"message": "hello world [3]"}' to the topic: device/data
Publish End
```
When looking at the MQTT test client in AWS IoT Core, you can see the messages:
{% hint style="success" %}
**Congratulations!** I’ve successfully sent data from a Raspberry Pi connected to Monogoto, to AWS IoT Core using the MQTT protocol.
{% endhint %}
### Next steps
* **Trigger actions using Lambdas** - [learn more](https://docs.aws.amazon.com/iot/latest/developerguide/iot-sql-functions.html#iot-func-aws-lambda)
* **Store data in DynamoDB** - [learn more](https://docs.aws.amazon.com/iot/latest/developerguide/iot-ddb-rule.html)
