How to Use st7735: Examples, Pinouts, and Specs

Introduction

The ST7735 is a low-power, full-color LCD driver manufactured by Arduino (Part ID: LCD). It is designed to support a variety of display resolutions, making it ideal for small displays in embedded systems. This component is widely used for rendering graphics and text in applications such as handheld devices, IoT projects, and portable instrumentation.

Explore Projects Built with st7735

Use Cirkit Designer to design, explore, and prototype these projects online. Some projects support real-time simulation. Click "Open Project" to start designing instantly!

RTL8720DN-Based Interactive Button-Controlled TFT Display

This circuit features an RTL8720DN microcontroller interfaced with a China ST7735S 160x128 TFT LCD display and four pushbuttons. The microcontroller reads the states of the pushbuttons and displays their statuses on the TFT LCD, providing a visual feedback system for button presses.

Open Project in Cirkit Designer

STM32F103C8T6-Based Spectral Sensor with ST7735S Display and Pushbutton Control

This circuit features an STM32F103C8T6 microcontroller interfaced with a China ST7735S 160x128 display and two spectral sensors (Adafruit AS7262 and AS7261). It also includes two pushbuttons for user input, with the microcontroller managing the display and sensor data processing.

Open Project in Cirkit Designer

ESP32-C6 and ST7735S Display: Wi-Fi Controlled TFT Display Module

This circuit features an ESP32-C6 microcontroller interfaced with a China ST7735S 160x128 TFT display. The ESP32-C6 controls the display via SPI communication, providing power, ground, and control signals to render graphics and text on the screen.

Open Project in Cirkit Designer

ESP32-S3 Based Vibration Detection System with TFT Display and Power Backup

This circuit features an ESP32-S3 microcontroller connected to various peripherals including an ADXL355 accelerometer, an SW-420 vibration sensor, a buzzer module, and an ILI9341 TFT display. The ESP32-S3 manages sensor inputs and provides output to the display and buzzer. Power management is handled by a 12V to 5V step-down converter, and a UPS ensures uninterrupted power supply, with a rocker switch to control the power flow.

Open Project in Cirkit Designer

Common Applications and Use Cases

• Handheld gaming devices
• Wearable technology
• IoT dashboards and displays
• Portable measurement tools
• Educational and hobbyist projects

Technical Specifications

The ST7735 LCD driver is a versatile component with the following key specifications:

Pin Configuration and Descriptions

The ST7735 typically uses an SPI interface with the following pin configuration:

Usage Instructions

The ST7735 can be easily integrated into a circuit using its SPI interface. Below are the steps and best practices for using the component:

Connecting the ST7735 to an Arduino UNO

1. Power Supply: Connect the VCC pin to the 3.3V output of the Arduino UNO and the GND pin to ground.
2. SPI Pins: Connect the SCL pin to Arduino's D13 (SCK) and the SDA pin to D11 (MOSI).
3. Control Pins:
   • Connect the RES pin to D8.
   • Connect the DC pin to D9.
   • Connect the CS pin to D10.
4. Backlight: Connect the BLK pin to 3.3V or a PWM pin for brightness control.

Example Code for Arduino UNO

Below is an example Arduino sketch to initialize and display text on the ST7735:

#include <Adafruit_GFX.h>    // Graphics library for ST7735
#include <Adafruit_ST7735.h> // ST7735 driver library

// Define pin connections
#define TFT_CS   10  // Chip select pin
#define TFT_RST   8  // Reset pin
#define TFT_DC    9  // Data/Command pin

// Initialize the ST7735 display
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_RST);

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);
  Serial.println("Initializing ST7735...");

  // Initialize the display
  tft.initR(INITR_BLACKTAB); // Use the Black Tab configuration
  tft.setRotation(1);        // Set display orientation
  tft.fillScreen(ST77XX_BLACK); // Clear the screen with black color

  // Display text
  tft.setTextColor(ST77XX_WHITE); // Set text color to white
  tft.setTextSize(2);             // Set text size
  tft.setCursor(10, 10);          // Set cursor position
  tft.println("Hello, ST7735!");  // Print text to the display
}

void loop() {
  // Nothing to do here
}

Best Practices

• Use a level shifter if your microcontroller operates at 5V logic levels, as the ST7735 is designed for 3.3V logic.
• Avoid long wires for SPI connections to minimize signal degradation.
• Use decoupling capacitors near the VCC and GND pins to ensure stable power supply.

Troubleshooting and FAQs

Common Issues and Solutions

1. Display Not Turning On

   • Ensure the VCC and GND connections are secure.
   • Verify that the backlight (BLK) pin is connected to power or a PWM signal.

2. No Output on the Screen

   • Check the SPI connections (SCL, SDA, CS, DC) for proper wiring.
   • Ensure the correct pin definitions are used in the code.

3. Flickering or Unstable Display

   • Use shorter wires for SPI connections.
   • Add decoupling capacitors near the power pins.

4. Incorrect Colors or Orientation

   • Verify the initialization code and ensure the correct configuration (e.g., INITR_BLACKTAB) is used.
   • Adjust the setRotation() function to match your desired orientation.

FAQs

Q: Can the ST7735 be powered with 5V?
A: No, the ST7735 operates at 2.8V to 3.3V. Use a voltage regulator or level shifter if your system uses 5V.

Q: How do I control the backlight brightness?
A: Connect the BLK pin to a PWM-capable pin on your microcontroller and use analogWrite() to adjust brightness.

Q: Is the ST7735 compatible with other microcontrollers?
A: Yes, the ST7735 can be used with any microcontroller that supports SPI communication, such as ESP32, STM32, or Raspberry Pi.

By following this documentation, you can effectively integrate and use the ST7735 in your projects.