iot rpi led message board - led message board

I made a wifi in this structure-
Use Raspberry Pi to connect LED message board (RPi).
The user will use the browser to connect to the web server of the Raspberry Pi and submit a short message that will be displayed on the 8x8 LED display.
Because it is good to interface the 8x8 LED matrix with the max72 19 driver in Python-
This project is documented by others on the Internet with a focus on building a web server interface and using ZeroMQ messages to manage incoming messages.
Update: here is
Up project IoT decimal/Hexadecimal 8x8 LED matrix drawing board (
I am the club host for the Code club girls and I came up with a simple project to teach students web interface design and messaging. )
The following hardware is required for this project: the hardware setup is the simplest part.
Simply connect the 5-wire ribbon cable in the LED matrix to the RPi of each max72 19 Library document. I used a pair.
Paste the LED unit into the double-sided foam band on the RPi housing.
I then made a case with a carton to store the RPi and battery.
RPi should have the following software: Python 3 RPi should already have Python 3installed.
While my code is written for Python 3, Python 2 should be able to make some minor changes.
Install Apache and enable Python CGI scripts.
Here are a few good resources to set up Apache on RPi, so I won't repeat it here.
Just follow the tutorial below to set up Apache and CGI. Make sure *.
Py scripts can be executed from the browser.
Max7291 drivers install the max7199 driver according to the latest installation guide: After installation, run the sample code matri_test.
Py, display "Hello World" on the LED matrix, according to the installation guide ".
This must work before going to the next step.
Why do we need a message?
Try to run the example code matri_test above.
On both terminal screens at the same time.
The system will allow multiple codes to run at the same time, but you will see an overlap of unwanted messages.
This may not be a problem in a single user environment, as you can make sure you can run only one program at a time. In a multi-
In a user environment like web, the system must create a first-in-first-out (First-In-First-Out)
Line up to make sure only one person can execute the code while others wait.
While there may be other solutions to do this, I decided to use ZeroMQ to manage FIFO queues.
The ZeroMQ server code contains the actual function call, when the web server acts as a ZeroMQ client query and submits a message to the ZeroMQ server, the function call displays one at a time on the LED matrix
This way, when multiple users can submit messages through a web page at the same time, the ZeroMQ server displays only one message at a time.
For this project, we just need to install the Python package pyzmq instead of the entire ZeroMQ package.
Run: Read the ZeroMQ guide and try out the hello world server and client examples in Python.
Copy the Python Sample Code of the server and client to the RPi and make sure they work before going to the next step.
In the web page, I used the bootstrap css/js framework to make the page look beautiful.
This is completely optional.
Download the attachment led_msg. tar.
Gz file for Apache root or subdirectory.
To decompress the tar file for gzip, run: this will create the following file: optionally, install the bootstrap css/js framework in a static directory.
Enter the URL of msg.
Make sure the web page appears in your browser.
No message has been submitted yet! ! !
Before submitting the message, you must start the ZeroMQ server to accept the message from the web page client and display it on the LED matrix.
If the ZeroMQ server is not running, nothing will be displayed on the screen.
Download the attachment max719_server.
The py code that points to your home directory, not the code in the Apache root directory that the web user can execute.
Run it as root: Now the ZeroMQ server is ready to receive messages from the web page.
Enter and submit a simple message from the web page.
If everything is set up correctly, you will see the message on the ZeroMQ server screen and on the LED matrix.
Just do control if you want to shut down the server-
C exit the server screen. That’s it.
Hope you like this project as much as I do.
One enhancement you can do is to make ZeroMQ communication asynchronous between the server and the client, so that the web page does not wait when other messages are displayed.
In addition, you can attach additional LED matrix in Cascade mode.
Then I will give it to you.