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Now, let's have a look at the first version of the original sketch to the original sketch version for

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the first iteration of the project.

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The sketch is based on the E.S.P and Take Client Library, which you can find here on GitHub at this

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location.

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So it's a fairly simple and quiddity library.

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But what I really like about it is that it's integrated.

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It allows you to handle EMCDDA team client requests, but it also handles especially to Wi-Fi, which

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means that we don't need to have a separate library for the wi fi bit.

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And there's very good documentation here.

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And examples, basically, you can get started with the library and subscribe and publish messages to

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the Breuker very, very quick with a very small amount of coding.

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Can have a look at the examples here as well, especially the what I used.

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I started with this example here and then implemented the various features based on this.

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As long as you know how to create a client and then subscribe to a topic or published topic, then you

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can pretty much do anything you want or need to do with the broker.

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And within a sketch, as you can see here.

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Start from line 17 and 18, you can interact with more than one topics.

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As the project becomes larger, you'll see that I'll be adding more topics here.

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So let's take things from beginning.

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First, I am creating the entity client here, and instead of having all the various credentials in

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the main application file, I've got them in a separate file called E.S.P through to Sigrid's, which

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looks like this.

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So this we can define your wi fi as a side password and username and password for the brokedown.

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Remember that these are the credentials that I created in the previous section when we were setting

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up the mosquito illiquidity broker.

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And you also need to get your broker's IP address for your Raspberry Pi so you can use this information

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here.

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And there is it's called Secrets The Page File.

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After that, I'm setting up the various pins, as we saw in the previous lecture in the schematic show.

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You really quickly here, we've got the thirty two for the transistor and then for the moisture sensor,

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in our case, for the potential metal that is connected to GPO 35.

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So I used this information right here.

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Then I have set up the the two topics.

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This is a topic that I am publishing, the soil humidity.

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And this topic here, the control topic is where my schedule is, where the data is subscribed to receive

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control, ratifications of values from the node red flow that I'll show you in the next lecture.

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Now, this line here, this value called soil humidity error range, I've set it here so that the SB

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32 will publish to this topic when the change in the detected soil humidity or the value from the consumer

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is large enough, because I don't want it to be posting constantly for single digit changes.

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So I wanted to have a range.

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And when the output from the sensor becomes larger or smaller by 10 units, then we'll send an update

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to Node read.

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I did this just to really conserve a bit of bandwidth and not to flood my note rate of flow with updates.

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All right, so these are a couple of additional variables here, the current soil humidity and then

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the last so committed so that the sketch remembers the last value that was sent to it by the note read

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Broken because they expected it to client cannot ask the entity broker for an update.

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The broker sends updates to the HP 32.

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So if the E.S.P 32 needs for some reason to remember the last value sent to it from the broker, they

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need to keep it locally.

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So that's what this variable is about.

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In the setup function, I'm setting up the analog to digital converter by attaching the serial humidity

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pin, setting the analog read resolution to 10 bits.

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So that gives us a range of zero to one thousand and twenty three for the readings from the soil humidity

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pin.

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And that is going to be an input.

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I'm setting the pump pen to be an output, these two lines to enable debugging messages and the Clippy

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Web up data, and that allows us to see debugging messages and information about what is happening with

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the requests in the serial monitor.

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And you can actually, once you do your testimony, you happy that everything works.

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You can just comment that out and not have to see any messages coming through this serial monitor.

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I just keep them in until we do a bit of testing later on in this section.

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The next function called On Connection Established, is a function that is called by the library when

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the entity broker sends an update to a topic that we ask, subscribe to the expected it to be subscribed

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so we can see here that we say client subscribed to control topic, which is this topic right here.

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And when the new data arrives to this topic from the note read flow, then the broker will forward it

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to any subscribed clients, which the ISP thirty two is going to be the subscriber client.

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And then when that happens, the library will call the pump control function, which if implemented

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further down and pass on the pump state that the note read flow has calculated for the controller.

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And let's jump into pump control since we have bumped into it.

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Here it is.

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So this pump control, it receives the pump state, which is a string.

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Pretty much everything in no direct messaging is really about strings, or at least that's how I have

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implemented the flow.

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It's going to send a string across.

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It's going to be either a zero or a one.

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And then depending on what it is, if it's a zero, it's going to turn off the pump by calling digital

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right on pump and taking that down to low.

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And if the pump state is one, then we're turning on the pump by calling digital.

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Right.

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And sending a high to pump in.

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Now, you'll notice here that I am using an array notation, and that's because I've got a string here

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sent from my note read a string is an array of characters.

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You want to know what the first cell in this array of characters contains.

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And that is why I am using the array notation and just passing index zero, because I'm only interested

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in the contents of the first cell of this array.

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There's other ways to implement this, but I thought I'd go with the string here just to keep things

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really simple.

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So let's have a look at what is happening inside the loop.

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The first thing that is happening inside the loop is to call the loop function on the client object,

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and that basically allows us to check for messages from the.

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And could it be broken?

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Apart from that, I take a reading from the soil to pen to see what is happening with your community

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in our prototyping phase that we are at the moment.

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I'll be taking readings from the potential metal and then printing out the various values stored in

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the variables.

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Now this is where publishing data to the end quiddity so your humidity topic takes place.

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If the difference between the current humidity and the previous soil humidity is larger than the range

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that I've specified earlier and larger than 10, then go ahead and send an update to the market it.

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So if this is true, then we use declined to publish function to send an update to the solar humidity

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topic, which is.

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This topic right here.

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And this is the value that we are publishing to this to this topic.

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You can see that I'm setting a string value of whatever I read from the soil humidity pin and then updating

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the lost soil humidity to be the current soil humidity.

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And actually to make this a little bit better, what I'll do is I will replace this with the value of

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the current soil humidity and fire, a little thing that makes it better.

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All right.

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So we've got a delay here and then the whole thing repeats again with calling the client loop.

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So that is about it.

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With the sketch.

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I'm going to compile it and upload it to my sensor.

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OK, and had a look at the serial monitor.

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All right, so it seems like it's working, there's nothing at the other end to interact with.

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So let's continue with the next lecture where we'll set up no direct.