Video 3.5 shedule ng trigger. In this video, we will do the following making hardware connections creating an Iam User Programming the Raspberry Pi testing. In the previous video, we sent a message at 10am from Cloud watch events today Sq sq. Now in this video, we will repeatedly check the queue for messages using the Raspberry Pi. If Raspberry Pi finds a message, then it should turn on the LED connected to it. So first let's quickly make the circuit connection.

First, I will place an LED on the breadboard important the LED cannot be directly connected to Raspberry Pi, because the Raspberry Pi can supply only a smaller amount of current which is about 60 milli ampere. If the LED is draw more current, then it can burn out the Raspberry Pi. Therefore, we need to place a resistor in this circuit which will ensure that only Appropriate current will flow and the Raspberry Pi will not get damaged. I am using a 330 ohm resistor which has a color code orange, orange brown gold, you can use any resistor between 330 to one kilo First we will make the ground connection. For this we will connect the ground pin on raspberry pi to the breadboard. Now connecting resistors from short leg of the led to the ground.

Next, we will connect the data pin connecting long leg of the LED to pin number 11. On Raspberry Pi. Yes, the connections are successfully made. Next, creating an IM user by should we create an IM user. for greater security and organization purpose, we will create an IM user. We need to create an IM user so that we can get an API access key and an access secret for accessing this Q Sq To further learn about Iam users, please check out the resources section.

Now, log into your AWS account and then search for Iam selected on the left hand side in the navigation pane, choose users. Now here on the top, you can add use it, choose Add User. Here, give a name for the user. I will give make a dummy. Next select AWS access state. Here we will choose programmatic access.

Choosing this will generate an access key ID and secret access key click on permissions. Here, we will create a group select Create group. First, I will give it a name main. Now, I will select administrator access here. If you don't find that policy, then you can search for it here. This program full access to all AWS services and resources, click on Next.

Click on Next. Now create user. Here you can download the dot CSV file, download it after downloading it open. Here you can find access key ID and secret access key. Next, programming the Raspberry Pi connected as berry pie to your PC, open the putty terminal. Since we have already installed the basic Python packages in the previous videos, here you will need to install only the Boto three.

So run Python hyphen m pip install Boto three, make sure this is installed. But what is Boto? Three? Let's see. Boto three is the Amazon Web Services software development kit for bite them this weekend right software If that makes use of services like Sq S, S three, EC two, etc. For more details, you can check out the Boto three documentation in the resources section.

Now, let's create a Python file, clear sudo nano changeling.py open the repository that you have downloaded at the beginning of this codes. Here, select section three, and then video 3.5. Open the Python file with the name r pi code to check Sq s, copy the entire code and paste it inside shed yuling dot p y Python file. Now let's understand this code. Here we import the required libraries. In these two lines, we need to give the access key ID and the secret access key which we downloaded by creating the Iam user copy access key and now we will paste it here.

Similarly, copy it Create access key and paste it here. Next region. Since I'm using North Virginia in my entire course, I am giving us hyphen, East hyphen, one. If you're also doing this project in North Virginia, then give us East one else open is to is selected you you created previously. And here at the bottom in the URL, you can find the region next queue URL, copy the entire URL from Sq s and paste it here. Now we are declaring a function pop underscore message with client and URL as arguments.

Next response. This takes the message from the queue with this specified queue URL. And here we are giving maximum number of messages as 10 since an Sq s via polling only for 10 messages each time now this response will have a message They received via splitting the message and received here. Okay, I think here it's difficult to explain the code. Let me open the code in Notepad. After reading the message, we are deleting it from the queue here.

This is because we don't want to read the same message repeatedly and turn on the LED. deleting this message ensures that we will turn on the LED only once for each message. Now, here we are declaring the argument length, weight time equal to 20. We are declaring time underscore start as time dot time function. This means that we are giving the start time of this function execution. Now, here we are using a try except block if try is not executed.

For example, if I give Ctrl C, then except condition will run that is a Pass Pass means that do nothing. Now coming to try loop you If there is any message, then run the script on.sh and after a delay of 20 seconds, run the script of.sh Okay, wait, I will tell you what are the script files, but before that, press Ctrl x and then y and Enter. Now, we will need to create two script files on.sh and off.sh. These script files will have the Python code for turning the LED on and off. Here in putty, we will give sudo nano on.sh Now, open the repository that you have downloaded at the beginning of this course. Here in the video 3.5 you will find two.sh files open on.sh copy these lines and now paste it here.

This first line tells the bash shell to execute the commands in the script. Every shell script you create will need On the first line of the script, next, we are initializing pin number 11. In this last line, we are making pin 11 Hi, this means that we are turning on the LED connected to pin 11 then control x and y and then enter. Similarly, we will create an auth.sh file sudo nano of.sh. Now copy the code in auth.sh file and paste it here. This code will set pin 11 to know, which will turn off the LED connected to pin 11.

Now, we have to make the two script files as executable files. For this, we need to use these comments sudo ch mod plus x on.sh and sudo ch mod plus x off.sh. Now, let's run the code Python shedule dot p by now Open is curious. Here, you can see the message that we have received at 10am. Now since our code has read the message and deleted the message, refresh the page. Yes, the number of messages is equal to zero.

Yes, our LED is turned on and waiting for 20 seconds. Yeah, it turned off. But is it the right way to always run your code manually like this? No. So let's automate this process. For this.

We will add a cron job to run our code every minute. So we use this command crontab hyphen E, which means that we are editing the crontab file. If it asks you to select an editor, then select slash bin slash nano. modify this text file by adding the following line in a new line at the end. We will add asterisk asterisk asterisk, asterisk, asterisk, Biden slash home slash pi slash scheduling dot p bi asterisk asterisk asterisk asterisk asterisk. This is a cron expression, which means that run every minute, every hour, every day, every month and every year, and then give buyten the location for your file, which you want to run.

Make sure that there is space between each asterisk. Now save by pressing Ctrl x and then y and enter. For more information, check out the resources section. Now open cloud watch events that GMT time is 3:47am. So now, I will show you a message at 3:50am. Yes, I'll wait for two minutes and then refresh my Sq s page.

Okay, refresh number of messages is equal to zero. And yes, the LED is turned on. So now we have successfully automated this process. We successfully completed scheduling events. Now, are you excited for controlling the LED or not by with the temperature data in the AWS cloud? Okay, we will look into it in the next section.

For now, I will end this video here. In this video, we learned the following making hardware connections, creating an Iam User Programming the Raspberry Pi testing. In this section, we learned the following introduction to SNS sending sensor data as notification introducing Amazon SQL as learning about cloud watch events, should you link a trigger? In the next section, we will trigger an LED connected to your micro computer based on the sensor data from a microcontroller