Control the LCD ST7735 Backlight Brightness Using PWM With Arduino

In this tutorial we are going to change the ST7735 SPI LCD Backlight brightness using a potentiometer & Arduino.

Watch the video!

Step 1: What You Will Need

• Arduino UNO (Or any other Arduino)
• LCD Display TFT 7735
• Potentiometer module
• 68 ohm Resistor (LCD Backlight draws around 30mA)
• Jumper wires
• Breadboard
• Visuino program: Download Visuino

Step 2: Brought by PCBWay

Thank you PCBWay for supporting this tutorial and helping users learn more about electronics.

What I like about the PCBWay is that you can get 10 boards for approximately $5 which is really cost effective for professional made boards, not to mention how much time you save!

Go check them out here. They also offer a lot of other stuff in case you might need it like assembly, 3D printing, CNC machining and a lot more.

Step 3: The Circuit

Step 4: Start Visuino, and Select the Arduino UNO Board Type

The Visuino: https://www.visuino.eu also needs to be installed. Download Free version or register for a Free Trial.

Start Visuino as shown in the first picture Click on the “Tools” button on the Arduino component (Picture 1) in Visuino When the dialog appears, select “Arduino UNO” as shown on Picture 2

Step 5: In Visuino Add & Set Components

• Add “TFT Color Display ST7735” component

Note: In case the display would not work try changing the Type under the properties window

• Double click on the “Display1” and in the “Elements” window
• Drag “Draw Text” to the left side and in the properties window set “Size to 3, “Text” to HELLO and “Y” to 20
• Drag “Draw Bitmap” to the left side and in the properties window set “Y” to 50 and select “Bitmap” and click on the 3 dots button
• In the “Bitmap Editor” click on the “Load” button and load the bitmap file in this case it was Visuino-logo.png
• Click “Ok” button to Close the “Bitmap Editor” window
• Close the “Elements” window

Step 6: In Visuino Connect Components

• Connect “Display1” component pin [Out] to Arduino pin SPI [In]
• Connect “Display1” component pin [Chip Select] to Arduino Digital pin[10]
• Connect “Display1” component pin [Reset] to Arduino Digital pin[8]
• Connect “Display1” component pin [Register Select] to Arduino Digital pin[9]
• Connect Arduino Analog pin [0] to Arduino digital pin [3]

Step 7: Generate, Compile, and Upload the Arduino Code

In Visuino, at the bottom click on the “Build” Tab, make sure the correct port is selected, then click on the “Compile/Build and Upload” button.

Step 8: Play