Overview

The ST7735 (and its variants ST7735S / ST7735R) is a single-chip controller/driver for 262K-color graphic TFT-LCD displays manufactured by Sitronix Technology. It is widely used on 1.8-inch 128x160 and 0.96-inch 80x160 color TFT screen modules.

The controller integrates a 132RGB x 162 frame memory buffer, display timing generator, and power supply circuits. Communication occurs over a fast 4-wire serial peripheral interface (SPI) with support for 16-bit RGB565 color depth (65,536 colors).

Quick reference

Module VCC3.3 V to 5.0 V DC (onboard LDO)
Chip VDD / VDDIO2.3 V to 3.3 V DC
Resolution128×160128 \times 160 pixels (or 80×16080 \times 160 pixels)
Color Depth16-bit RGB565 (65,536 colors) or 18-bit RGB666 (262,144 colors)
Communication interface4-wire SPI (SCL, SDA, CS, DC, RES)
Maximum SPI Clock15 MHz
LED Backlight Supply3.3 V DC (draws ~40 mA)

Pinout

Standard 8-Pin 1.8-inch TFT Module Header

PinNameTypeDescription
1GNDPowerGround (0 V)
2VCCPowerSupply voltage (+3.3 V to +5.0 V DC)
3SCL / SCKDigital InputSPI Clock input line
4SDA / MOSIDigital InputSPI Data Input line
5RES / RSTDigital InputActive-LOW Hardware Reset line
6DC / A0Digital InputData / Command control pin (LOW = Command, HIGH = Data)
7CSDigital InputSPI Chip Select line (Active-LOW)
8BLK / LEDPower / PWMLED Backlight power control (HIGH / 3.3V = Backlight ON, PWM for dimming)

Specifications

ParameterSymbolMinTypMaxUnitConditions
Supply Voltage (Module)VCCV_{CC}3.35.05.5VDC
Supply Voltage (Chip)VDDV_{DD}2.32.83.3VDC
Logic High InputVIHV_{IH}0.7VDD0.7 V_{DD}—VDDV_{DD}VSCL, SDA, DC, CS
Logic Low InputVILV_{IL}0—0.3VDD0.3 V_{DD}VSCL, SDA, DC, CS
Driver Operating CurrentIDDI_{DD}—1015mANormal display operation
Backlight CurrentILEDI_{LED}—4050mAVLED=3.3 VV_{LED} = 3.3\text{ V}

Key Command Table

Address HexCommand NameDescription
0x01SWRESETSoftware Reset command
0x11SLPOUTSleep Out (Turn on internal charge pump oscillator)
0x29DISPONDisplay ON command
0x2ACASETColumn Address Set (XstartX_{start} to XendX_{end})
0x2BRASETRow Address Set (YstartY_{start} to YendY_{end})
0x2CRAMWRMemory Write (Stream 16-bit RGB565 pixel color data)
0x36MADCTLMemory Data Access Control (Orientation, BGR/RGB color order)
0x3ACOLMODInterface Pixel Format (0x05 = 16-bit RGB565)

Wiring

ST7735 Module Pin→Microcontroller (Arduino Uno / ESP32)Notes
GNDGNDGround
VCC5V (or 3.3V)Module power supply
SCLSPI SCK (D13 on Uno / GPIO18 on ESP32)SPI Clock
SDASPI MOSI (D11 on Uno / GPIO23 on ESP32)SPI Master Output
RESGPIO Pin (e.g. D8 on Uno / GPIO4 on ESP32)Reset pin
DCGPIO Pin (e.g. D9 on Uno / GPIO2 on ESP32)Data/Command pin
CSSPI SS (e.g. D10 on Uno / GPIO5 on ESP32)Chip Select
BLK3.3V (or PWM GPIO Pin)Backlight control
Warning

3.3V Signal Logic Level Requirement: The ST7735 controller operates on 3.3V logic levels. Connecting 5V SPI data lines directly from an Arduino Uno to the ST7735 SCL, SDA, and DC pins without 1 kΩ/2 kΩ1\text{ k}\Omega / 2\text{ k}\Omega resistor dividers can cause white screen glitches or destroy the display controller over time.

Common mistakes

  • Tab Color Configuration Mismatch: ST7735 breakout modules come in different silicon revisions identified by colored protective film tabs (ST7735B, ST7735R Red Tab, ST7735R Green Tab, ST7735S Black Tab). Initializing a Green Tab display with Red Tab software settings causes shifted screen offsets and inverted colors (Red/Blue swap).
  • Leaving Backlight (BLK) Floating: On some breakout modules, the BLK pin must be connected to 3.3V; leaving it floating results in a black screen.
  • Forgetting SLPOUT Delay: After sending the SLPOUT (0x11) command, software MUST pause for 120 ms before sending the DISPON (0x29) command to allow the internal charge pump to stabilize.

Notes

  • Supported by popular graphics libraries such as Adafruit_ST7735, TFT_eSPI (ESP32), and TFT_ST7735 (ESPHome).

Assets & downloads