Blue screen LCD12864 Chinese font backlight 5V ST7920
Specific parameters:
Appearance size 94*70 Screen size 77*50
The LCD12864 interface is defined as follows:
The parallel port mode is as follows:
Pin 1: VSS is the ground power supply
Pin 2: VDD is connected to 5V positive power supply
Pin 3: V0 is the LCD contrast adjustment terminal, the contrast is the weakest when connected to a positive power supply, and the highest when the grounded power supply is connected
Pin 4: RS is the register selection, select the data register when the high level, select the instruction register when the low level.
Pin 5: R/W When both R/W and E are high level, the data is read to DB0~DB7; when R/W is low level, E changes from high level to low level, DB0~DB7 data is written to the IR or DR register.
Pin 6: E enable
Pins 7 to 14: DB0 to DB7 are 8-bit bidirectional data lines.
Pin 15: PSB parallel/serial selection. When PSB is high, it is in parallel mode; when PSB is low, it is in serial mode. If your LCD screen pin 15 is CS1, please click here.
The 16th foot: NC empty foot. If your LCD screen pin 16 is CS2, please click here.
Pin 17: /RESET reset pin. Low level has suburbs.
Pin 18: VOUT LCD drive voltage output terminal, can not be connected.
Pin 19: A Positive pole of backlight power supply, connect to +5V.
Pin 20: K negative power supply of backlight, ground.
The serial port mode is as follows:
Pin 1: VSS is the ground power supply
Pin 2: VDD is connected to 5V positive power supply
Pin 3: V0 is the LCD contrast adjustment terminal, the contrast is the weakest when connected to a positive power supply, and the highest when the grounded power supply is connected
Pin 4: CS chip select, active high.
The 5th foot: SID serial data input end.
Pin 6: CLK Serial synchronization clock.
Pin 15: PSB parallel/serial selection. When PSB is high, it is in parallel mode; when PSB is low, it is in serial mode.
Pin 17: /RESET reset pin. Low level has suburbs.
Pin 19: A Positive pole of backlight power supply, connect to +5V.
Pin 20: K negative power supply of backlight, ground.
Note:
that there is no pin header, the pin header is sold separately!

Example code:
#include <U8g2lib.h>
#include <U8x8lib.h>
U8G2_ST7920_128X64_1_HW_SPI u8g2(U8G2_R0, /* CS=*/ 10, /* reset=*/ 8);
void setup() {
Serial.begin(9600);
u8g2.begin();
u8g2.enableUTF8Print();
u8g2.setFont(u8g2_font_helvB08_tf);
u8g2.setColorIndex(1);
}
void loop() {
u8g2.firstPage();
do {
draw();
} while( u8g2.nextPage() );
}
void draw(){
readTemperature();
readHumidity();
u8g2.drawFrame(0,0,128,31);
u8g2.drawFrame(0,33,128,31);
u8g2.drawStr( 15, 20, "www.MikroElec.com");
u8g2.drawStr(15,53, "Line ID: @MikroElec");
}