How to Use ST7565: Examples, Pinouts, and Specs

The ST7565 is a versatile graphic LCD controller designed to drive monochrome LCD displays. It supports a variety of resolutions, making it suitable for a wide range of applications. The controller is commonly used in embedded systems to display text, graphics, and custom images. Its built-in serial interface simplifies communication with microcontrollers, making it a popular choice for projects requiring compact and efficient display solutions.

• Embedded systems and IoT devices
• Industrial control panels
• Handheld devices and portable instruments
• Consumer electronics with graphical user interfaces
• Educational and hobbyist projects

The ST7565 is a highly capable LCD controller with the following key specifications:

The ST7565 has multiple pins for communication and control. Below is a table describing the key pins:

The ST7565 is typically used in conjunction with a microcontroller, such as an Arduino UNO, to drive a graphic LCD. Below are the steps to use the ST7565 in a circuit:

• Power Supply: Connect the VDD pin to a 3.3V power source and the VSS pin to ground.
• Communication Interface: Use the SPI interface for communication:
  • Connect the CS pin to a digital output pin on the microcontroller.
  • Connect the SCL pin to the SPI clock pin (e.g., Arduino pin 13).
  • Connect the SDA pin to the SPI data pin (e.g., Arduino pin 11).
  • Connect the A0 pin to a digital pin to toggle between data and command modes.
• Reset: Connect the RST pin to a digital pin for resetting the controller.

To control the ST7565, you can use libraries such as the Adafruit_ST7565 library. Below is an example Arduino sketch to initialize and display text on an ST7565-based LCD:

#include <Adafruit_GFX.h>       // Graphics library for text and shapes
#include <Adafruit_ST7565.h>    // Library for ST7565 controller

// Define pin connections
#define SCLK 13  // Serial clock pin
#define SID  11  // Serial data pin
#define A0   9   // Data/Command pin
#define RST  8   // Reset pin
#define CS   10  // Chip select pin

// Initialize the ST7565 display
Adafruit_ST7565 display(CS, RST, A0, SID, SCLK);

void setup() {
  display.begin(0x18);  // Initialize display with contrast value (0x18 is typical)
  display.clearDisplay();  // Clear the display buffer

  // Display text
  display.setTextSize(1);  // Set text size to 1 (smallest)
  display.setTextColor(BLACK);  // Set text color to black
  display.setCursor(0, 0);  // Set cursor to top-left corner
  display.print("Hello, ST7565!");  // Print text to the display
  display.display();  // Update the display with the buffer content
}

void loop() {
  // No actions in the loop for this example
}

• Voltage Levels: Ensure the microcontroller's logic levels are compatible with the ST7565's 3.3V operating voltage. Use level shifters if necessary.
• Contrast Adjustment: The contrast value (e.g., 0x18 in the example) may need to be adjusted based on the display and operating conditions.
• Capacitors: Properly connect external capacitors to the CAP1+, CAP1-, CAP2+, and CAP2- pins for stable operation of the internal voltage booster.

1. Display Not Turning On

   • Cause: Incorrect power supply or loose connections.
   • Solution: Verify that the VDD and VSS pins are properly connected to a 3.3V power source and ground.

2. No Text or Graphics Displayed

   • Cause: Incorrect initialization or communication settings.
   • Solution: Ensure the SPI pins are correctly connected and the initialization code matches the hardware setup.

3. Flickering or Unstable Display

   • Cause: Insufficient decoupling capacitors or unstable power supply.
   • Solution: Add decoupling capacitors (e.g., 0.1µF) near the power pins and ensure a stable 3.3V supply.

4. Contrast Issues

   • Cause: Incorrect contrast setting.
   • Solution: Adjust the contrast value in the initialization code (display.begin()).

• Can the ST7565 work with 5V microcontrollers like Arduino UNO?

  • Yes, but you need level shifters to convert the 5V logic signals to 3.3V.

• What is the maximum resolution supported by the ST7565?

  • The ST7565 supports resolutions up to 132x64 pixels.

• Can I use the ST7565 in parallel mode?

  • Yes, the ST7565 supports both serial (SPI) and parallel communication modes. However, SPI is more commonly used due to its simplicity and fewer required pins.

• How do I display custom graphics?

  • Use a graphics library like Adafruit_GFX to draw shapes or load bitmap images into the display buffer.

By following this documentation, you can effectively integrate the ST7565 into your projects and troubleshoot common issues.