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This repository contains a program to read a config file from an SD Card and use the data to change the program execution on an Arduino UNO R3/R4/Mega nad a 3.5" TFT LCD Shield, as shown below -

Most 3.5" TFT LCD Touch displays use the ILI9486 Display Driver and include a resistive touchscreen.The PCB Layout & silkscreen text may vary slightly between displays. This does not change their behaviour and functionality. This repository depends on the following libraries -

• Adafruit Touch Screen Library to manage touch input
• Adafruit GFX Library for graphics primitives
• This fork of the MCUFriend KBV library to drive the display (this makes it compatible with the UNO R4)

The program has been written using PlatformIO, and has been tested on theArduino UNO R3,Arduino UNO R4 Minima &Arduino UNO R4 WiFi.

Since this project has been written using PlatformIO by default, simply run the following commands to fetch the libraries, build the project and upload the program -

pio pkg installpio runpio run --target upload

Create a new sketch and copy the contents ofsrc/main.cpp from this repository into the default.ino file. Create a new tab/file in the IDE namedconstants.h and copy the contents ofsrc/constants.h from this repository into this file.

Install the Adafruit Touch Screen Library and Adafruit GFX Library from the Library Manager (underSketch>Include Library>Manage Libraries...)

Downloadthis repository as a ZIP file and install it by navigating toSketch>Include Library>Add .ZIP Library, and selecting the downloaded file from the file explorer.

After this, you can Build and Upload the program as usual.

As soon as the program is uploaded, the display should turn black and the following message should be printed on the display -

Next, create a file calledCONFIG.TXT on aFAT formatted SD Card, which will be inserted into the SD Card slot on the TFT LCD Shield. The file must contain three color codes, which will be used to draw three squares on the display. Two examples are shown below -

Config file -

square-1-color" = f800""square-2-color" = "07E0""square-3-color" = "001F"

Result -

Config file -

"square-1-color"  =   "fFe0" // Yellow"square-2-color" = "7ff" // Cyan"square-3-color"  = "F81F" // Magenta

Result -

Some common problems and their solutions -