2inch LCD Module

Instruction

This is a general LCD display Module, IPS screen, 2inch diagonal, 240×320 resolution, with embedded controller, communicating via SPI interface

Feature

  • SPI interface, requires minimum GPIO for controlling
  • Comes with development resources and manual

Specifications

  • Driver: ST7789
  • Interface: SPI
  • Display color: RGB, 262K color
  • Resolution: 240×320
  • Backlight: LED
  • Operating voltage: 3.3V

Interface

SYMBOLDescription
VCCPower (3.3V input)
GNDGround
DINSPI data input
CLKSPI clock input
CSChip selection, low active
DCData/Command selection (high for data, low for command)
RSTReset, low active
BLBacklight

Hardware description

ST7789V supports RGB444, RGB565 and RGB666 three formats. This LCD uses RGB565.
For most of the LCD controller, there are several interfaces for choosing, this module we use SPI interface which is fast and simple.

Communication protocol


Note: It is not like the tradition SPI protocol, it only uses MOSI to send data from master to slave for LCD display. For details please refer to Datasheet Page 105.

RESX: Reset, should be pull-down when power on, set to 1 other time.

CSX: Slave chip select. The chip is enabled only CS is set Low

D/CX: Data/Command selection; DC=0, write command; DC=1, write data

SDA: Data transmitted. (RGB data)

SCL: SPI clock

The SPI communication protocol of the data transmission uses control bits: clock phase (CPHA) and clock polarity (CPOL):

CPOL defines the level while the synchronization clock is idle. If CPOL=0, then it is LOW.

CPHA defines at whish clock’s tick the data transmission starts. CPHL=0 – at the first one, otherwise at the second one

This combination of two bits provides 4 modes of SPI data transmission. The commonly used is SPI0 mode, i.e. GPHL=0 and CPOL=0.

According to the figure above, data transmitting begins at the first falling edge, 8bit data are transmitted at one clock cycle. It is SPI0. MSB.

Raspberry Pi examples

For Raspberry Pi we provide examples based on C and python

Enable SPI

Open terminal and run commands to enable SPI interface

sudo raspi-config

Choose Interfacing Options -> SPI -> Yes

Then reboot Raspberry Pi

Libraries installation

  • BCM2835
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.60.tar.gz
tar zxvf bcm2835-1.60.tar.gz 
cd bcm2835-1.60/
sudo ./configure
sudo make
sudo make check
sudo make install
  • WiringPi
sudo apt-get install wiringpi
cd /tmp
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
gpio -v
  • Python2
sudo apt-get updata
sudo apt-get install python-pip 
sudo pip install RPi.GPIO
sudo pip install spidev
sudo apt-get install python-imaging
  • Python3
sudo apt-get update
sudo apt-get install python3-pip
sudo pip3 install RPi.GPIO
sudo pip3 install spidev
sudo apt-get install python3-imaging

Hardware connection


Please notice, that wires colors may vary. Use pins designations for wiring.

2inch LCDBoard numberBCM number
VCC3.3V3.3V
GNDGNDGND
DIN19MOSI
CLK23SCLK
CS24CE0
DC22P25
RST13P27
BL12P18

Download examples

Open terminal and download examples

sudo apt-get install p7zip-full
wget http://www.waveshare.net/w/upload/1/19/2inch_LCD_Module_code.7z
7z x 2inch_LCD_Module_code.7z  -r -o./2inch_LCD_Module_code
sudo chmod 777 -R  2inch_LCD_Module_code
cd 2inch_LCD_Module_code/RaspberryPi\&JetsonNano/

Test examples

  • C codes
cd c
sudo make clean
sudo make
sudo ./main
  • Python codes
cd python/examples
sudo python main.py

Expected result

  1. The display is cleaned to white
  2. Display numbers and strings
  3. Draw a rectangle
  4. Draw a line
  5. Draw five circles
  6. Display a 100x100 image
  7. display a 240x320 image

STM32 examples

  • Download the demo codes from Waveshare wiki, the path of STM32 codes is ~/STM32/
  • Open the project from \XNUCLEO-F103RB\MDK-ARM\ with Keil software. Note that the codes are based on HAL libraries.
  • The development board we use is WaveshareXNUCLEO-F103RB

Hardware connection

2inch LCDXNUCLEO-F103RB
VCC5V
GNDGND
DINPA7
CLKPA5
CSPB6
DCPA8
RSTPA9
BLPC7

Expected result

  1. The display is cleaned to white
  2. Display numbers and strings
  3. Draw a rectangle
  4. Draw a line
  5. Draw five circles
  6. Display a 70x70 image

Arduino

  • Download examples from wiki. Unzip it. The path of Arduino examples is ~/Arduino UNO/...
  • Copyt the folders in Arduino directory to 【Installation directory】/libraries/ (Generally the installation directory is C:\Program Files (x86)\Arduino\libraries)
  • Open Arduino IDE software, and click File -> Examples to check if LCD_2inch codes are there.
  • The development board used is Arduino UNO.

Hardware connection

2inch LCDUNO PLUS
VCC5V
GNDGND
DIND11
CLKD12
CSD10
DCD7
RSTD8
BLD9

Expected result

  1. The display is cleaned to white
  2. Display numbers and strings
  3. Draw a rectangle
  4. Draw a line
  5. Draw five circles
  6. Display a 70x70 image
Price: $9.89
Part Number: 2inch LCD Module
Brand: Spotpear
SKU: 0201209