Introduction

1.44-inch LCD HAT, SPI interfaces.

Operating voltage: 3.3VSpecification

• Interface: SPI
• LCD type: TFT
• Controller: ST7735S
• Resolution: 128*128 (Pixel)
• Display size: 25.5*26.5(mm)
• Pixel size: 0.20(W) *0.20(H)(MM)
• Dimension: 65 x 30.2 (mm)

Pinout

LCD and the controller

The ST7735S is a 132*162 pixel LCD controller, but the pixel of the 1.44-inch LCD HAT is 128*128. So we have made some processing on the display: the horizontal direction starts from the second pixel to guarantee the location of RAM in the LCD is consistent with the actual location at the same time.
This LCD accepts 8-bits/9-bits/16-bits/18-bit parallel interfaces, which are RGB444, RGB565, and RGB666. The color format used in demo codes is RGB565.
This LCD uses a 4-wire SPI interface for reducing GPIO, and the communication speed will be faster.

Working Protocol

Note: Different from the traditional SPI protocol, the data line from the slave to the master is hidden since the device only has a display requirement.
RESX Is the reset pin, it should be low when powering the module and be higher at other times.
CSX is slave chip select, when CS is low, the chip is enabled.
D/CX is data/command control pin, when DC = 0, write command, when DC = 1, write data
SDA is the data pin for transmitting RGB data, it works as the MOSI pin of the SPI interface;
SCL works the SCLK pins of the SPI interface.
SPI communication has data transfer timing, which is combined by CPHA and CPOL.
CPOL determines the level of the serial synchronous clock at an idle state. When CPOL = 0, the level is Low. However, CPOL has little effect on the transmission.
CPHA determines whether data is collected at the first clock edge or at the second clock edge of the serial synchronous clock; when CPHL = 0, data is collected at the first clock edge.
There are 4 SPI communication modes. SPI0 is commonly used, in which CPHL = 0, CPOL = 0.

Working with Raspberry Pi

Enable SPI interface

• Open terminal, use command to enter the configuration page
  

sudo raspi-config
Choose Interfacing Options -> SPI -> Yes  to enable SPI interface

Reboot Raspberry Pi：

sudo reboot

Please make sure the SPI is not occupied by other devices, you can check in the middle of /boot/config.txt

Install Library

If you use bookworm system, only the lgpio library is available, bcm2835 and wiringPi libarary cannot be installed or used. Please note that the python library does not need to install, you can directly run the demo.

BCM2835

#Open the Raspberry Pi terminal and run the following command
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.71.tar.gz
tar zxvf bcm2835-1.71.tar.gz 
cd bcm2835-1.71/
sudo ./configure && sudo make && sudo make check && sudo make install
# For more, you can refer to the official website at: http://www.airspayce.com/mikem/bcm2835/

WiringPi

#Open the Raspberry Pi terminal and run the following command
cd
sudo apt-get install wiringpi
#For Raspberry Pi systems after May 2019 (earlier than that can be executed without), an upgrade may be required:
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
gpio -v
# Run gpio -v and version 2.52 will appear, if it doesn't it means there was an installation error

# Bullseye branch system using the following command:
git clone https://github.com/WiringPi/WiringPi
cd WiringPi
. /build
gpio -v
# Run gpio -v and version 2.70 will appear, if it doesn't it means there was an installation error

lgpio

wget https://github.com/joan2937/lg/archive/master.zip
unzip master.zip
cd lg-master
sudo make install 
#for more details, you can refer to https://github.com/gpiozero/lg

Python

sudo apt-get update
sudo apt-get install python3-pip
sudo apt-get install python3-pil
sudo apt-get install python3-numpy
sudo pip3 install spidev

Download Examples

Open the Raspberry Pi terminal and run the following command:

sudo apt-get install p7zip-full -y
wget https://files.waveshare.com/upload/f/fa/1.44inch-LCD-HAT-Code.7z
7z x 1.44inch-LCD-HAT-Code.7z
sudo chmod 777 -R 1.44inch-LCD-HAT-Code
cd 1.44inch-LCD-HAT-Code/RaspberryPi/

Test Program

C codes

cd c
sudo make clean
make 
sudo ./main

For Raspberry Pi 4B and the system later than raspbian_lite-2019-06-20, you need to set it as follows, and the key can be input normally.

sudo nano /boot/config.txt
#Add the following:
gpio=6,19,5,26,13,21,20,16=pu

python

cd python
sudo python main.py
sudo python key_demo.py

FBCP Driver

PS: FBCP currently is not compatible with the 64-bit Raspberry Pi system or Bookworm, and it is recommended to use the 32-bit system.
The Framebuffer uses a memory area to store the display content and changes the data in the memory to change the display content.

There is an open-source project on github: fbcp-ili9341. Compared with other fbcp projects, this project uses partial refresh and DMA to achieve a refresh rate of up to 60fps.

Compile and Run

sudo apt-get install cmake -y
cd ~
wget https://files.waveshare.com/upload/1/18/Waveshare_fbcp.zip
unzip Waveshare_fbcp.zip
cd Waveshare_fbcp
mkdir build
cd build

If you are using 1.44inch_LCD_HAT:

cmake -DSPI_BUS_CLOCK_DIVISOR=20 -DWAVESHARE_1INCH44_LCD_HAT=ON -DBACKLIGHT_CONTROL=ON -DSTATISTICS=0 ..

If you are using 1.3inch_LCD_HAT:

cmake -DSPI_BUS_CLOCK_DIVISOR=20 -DWAVESHARE_1INCH3_LCD_HAT=ON -DBACKLIGHT_CONTROL=ON -DSTATISTICS=0 ..

Then

make -j
sudo ./fbcp

Auto-start when Power on

sudo cp ~/waveshare_fbcp/build/fbcp /usr/local/bin/fbcp
sudo nano /etc/rc.local

And then add fbcp& before exit 0, as the picture below.

Set the Display Resolution

Set the user interface display size in the /boot/config.txt file.

sudo nano /boot/config.txt

Then add the following lines at the end of the config.txt.

hdmi_force_hotplug=1
hdmi_cvt=300 300 60 1 0 0 0
hdmi_group=2
hdmi_mode=87
display_rotate=0

And then reboot the system

sudo reboot

After rebooting the system, the Raspberry Pi OS user interface will be displayed.

Analog Mouse

There is a joystick and three buttons on the panel of the module, which we can use to control the mouse of the Raspberry Pi.

• Install the library, then download and run the demo.

#python2
sudo apt-get install python-xlib
sudo pip install PyMouse
wget https://files.waveshare.com/upload/d/d3/Mouse.7z
7z x Mouse.7z
sudo python mouse.py
#python3
sudo apt-get install python3-xlib
sudo pip3 install PyMouse
sudo pip3 install unix
sudo pip3 install PyUserInput
wget https://files.waveshare.com/upload/d/d3/Mouse.7z
7z x Mouse.7z
sudo python3 mouse.py

• 【Note】The mouse.py needs to run under the graphical interface, which will not run under the SSH login. You can skip this step directly, the Pi will run the demo automatically by booting up.
• If you are using the Raspberry PI 4B and the version of your image is after raspbian_lite-2019-06-20, you need to set it as below:

sudo nano /boot/config.txt

And then add the following line at the end of the config.txt.

gpio=6,19,5,26,13,21,20,16=pu

Use the joystick to move up, down, left, and right, you can see that the mouse is moving.

• Set the auto-start when power on

Be careful not to add it to /etc/rc.local, because rc.local will be executed before the system enters the desktop, and if the PyMouse module runs on the command line interface, it will report an error that there is no mouse event, so we need to execute the following:

cd .config/
mkdir autostart
cd autostart/
sudo nano local.desktop

And then add the following lines at the end of the local.desktop

#python2
[Desktop Entry]
Type=Application
Exec=python /home/pi/mouse.py
#python3
[Desktop Entry]
Type=Application
Exec=python3 /home/pi/mouse.py

Reboot the system, you can use the buttons to control the mouse.

sudo reboot

Others

For connecting to the game machine, you can refer to the following links:
https://www.sudomod.com/forum/viewtopic.php?f=11&t=5371&start=10
https://pi0cket.com/guides/tiny-software-for-tinypi/#more-99

Resources

Document

• Schematic

Demo

• Raspberry code
• Sample Demo

Datasheet

• ST7735S

Software

• lcd
• Image2Lcd

FAQ

gpio=6,19,5,26,13,21,20,16=pu

Support

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