Video 4.4 using the HD 11 Raspberry Pi part two. In this video, we will be completing the third task of the challenge. We'll also see how to visualize the data on your Raspberry Pi and the Arduino. We'll then take a look at how to display the data on an LCD display connected with your Raspberry Pi using node red. Let's proceed with the third task. So we now know how to communicate with other devices using mq TT.
So let's add that condition I told you before. If temperature is greater than 25 degrees centigrade, and humidity is less than 10%, then your temperature and humidity data is sent to your Android via mq TT. Pause the video. Try out the flow and come back once you're done. Your flow should look similar to this. You should have also configured a flow with mq TT subscribe node in your Android.
This is the node rate editor running on my Android. I have just added a debug node to mq TT node to view the arriving messages. I have changed the humidity condition to more than 10%. For now, so that I can show you the values. You can see that I'm getting an error message from Twitter node, saying that my status is duplicate. This happens because we are sending the same kind of data every time.
And the API doesn't allow that because it considers it as spam. Now let's add dashboard nodes to present this data nicely in both Raspberry Pi and Android. First in Raspberry Pi, I'm going to add chart node for temporary And gauge note for humidity, customize them until you're satisfied. And then deploy. Next is dashboards in Android. I'm going to have the same chart node with a twist.
I'm going to map temperature and humidity on the same chart using this function node. Let me customize this and deploy now let's check out both of them. Looks amazing, isn't it? How does this look on your phone? Looks cool, isn't it? Okay, now for the next part, visualizing the same data on an LCD connected to your Raspberry Pi.
First, let's interface our LCD to the Raspberry Pi. If you don't know about LCDs, then you must check out a link in the resources and then proceed with this video. Do I have already connected my LCD, I have attached the fritzing to the resources. Note that I have used the last four data pins of the LCD, because the node which we're going to use will send data using those pins only node. Yes, there is a special RPI LCD node in the library we have to first install it. Once that is done, we have to enter the RS enable and the data pin values in commerce.
Then we have to send the text to be shown in string format inside the message payload. If you want to output a string on the second line of the LCD, like we're going to do, then you must mention it like to colon text to make the text show in the second line. We can do that in a template node. Let's add one and format it this way. then deploy and see what happens. grid, everything works.
This is the end of this video. In this video, we finished the third task continued from the last challenge. We also saw what it would look like in displaying data on the dashboard, from the Raspberry Pi and on your Android. We also learned how to visualize data on an LCD interface with your Raspberry Pi. In the next video, we'll learn to build the same weather station using Arduino