Electronic Shelf Label

In this tutorial, you'll learn how to make an Electronic shelf label. For those of you who don't know what it is, an electronic shelf label (ESL) is a device that is used by retailers for displaying prices on shelves. This device stores data in the SPIFFS memory. SPIFFS is a non-volatile memory, so it can retain the stored information even after power is removed.

• ESP8266 x1
• I2C Port Expander Module for LCD x1
• 24×2 Character LCD (DMC24227) x1 *Can be replaced by 16x2 display

To get the display's address, upload this sketch to ESP.

https://playground.arduino.cc/Main/I2cScanner/

Then open the Serial Monitor, and set the baud rate to 9600. If you've done everything right, you should see the display's address.

You can get it here https://github.com/Northstrix/Electronic_Shelf_La...

Firstly, replace the display's address (highlighted by yellow) with the one you got from the step 2.

Secondly, replace Blackberry 1291 with your SSID.
Thirdly, replace seasidehillsESL with your password.

Your access point has to be turned on before powering up the device. Otherwise, you'll have to reboot ESP a couple of times.

The display will be clear until the device will connect to your access point.

Right after the device will connect to the access point, you'll see something like this on the display.

If the display is still clear:

1) Check if the display's address that you've entered into the firmware is correct;
2) Check if your network credentials are correct;
3) Check if all connections are correct and there are no bad wires;
4) Adjust the potentiometer on the I2C Port Expander Module.

Open the Serial Monitor and set the baud rate to 115200. In case you've done everything right, you should see a message like this.

You should see this page on that step.

Important note: The device from which you are going to control the ESL has to be in the same network as the ESL.

Enter the label that will be displayed in the upper part of the display.

You'll see this message if everything's fine.

Just enter the price and press send. A price will be displayed in the bottom part of the display.

Congratulations, if you made it that far, you now have your own ESL.

P.s. You can also connect a 16x02 display instead of a 24x02 one without changing a line of code.

I hope it was useful for you.