Any porting to STM32CubeIDE and ST7920 over hardware or software SPI?

[Leo928]

Any chance that there is similar or exact port to STM32CubeIDE and ST7920 over hardware or software SPI? Many thanks

[olikraus]

You could check this page https://github.com/olikraus/u8g2/wiki/Porting-to-new-MCU-platform for generic and specific porting instructions.

[Leo928]

Many thanks, olikraus! Some posts say ST7920 is "sensitive"??? Are people saying the chip only work in narrow range of signal timing (while other chip can take signal varying over wider timing)??

[olikraus]

I personally feel that this display is sensitive: If wires are too long or the timing not as expected, then the display behaves in wrong. I always felt that displays like ST7565 are more reliable. It least I had much lesser problems.

[Leo928]

On Arduino ATMEGA2560, which mode(s) can u8g2 works with ST7920?
SPI_hardware, SPI_software, parallel 4 bit 8080 mode, parallel 8 bits 8080 mode, parallel 4 bit 6800 mode, parallel 8 bits 6800 mode???
Seem I use the wrong setting, it outputs 8 bits data on SPI_4wires_software mode. ST7920 expects firstly, "special 8 bits sync" and then 8 bits containing d7_to_d4 and then, 8 bits containing d3_to_d0. As page 26 on version 4 data sheet

[Leo928]

Many thanks for providing this wonderful library for use by community.

We have tested the following configuration and worked nicely.

Arduino IDE 2.3.2 on Window 11.

u8g2 library, version 2.34.22, downloaded by Arduino Library Manager

LCD Display 128x64, Monochrome, 2.8 inches diameter, ST7920 controller chip, White LED backlight, Display is WHITE characters on BLUE background

MCU board Arduino ATMEGA2560

Label on LCD display marked as LCD_xxx. Pin label is pin of Arduino UNO (you may check for pin of ATMEGA 2560)

Power supply for LCD controller
LCD_VDD 3.3 volts
LCD_VSS Ground

Backlight LED
LCD_A 5 volts
LCD_K Ground

Software SPI
U8G2_ST7920_128X64_F_SW_SPI u8g2(U8G2_R0, /* E_LCD clock=/ 13, / RW_LCD data=/ 11, / RS_LCD CS=/ 10, / reset=*/ 8);
LCD_E is CLOCK to pin 13 of Arduino
LCD_RW is DATA_INTO_LCD (MOSI of Arduino) to pin 11 of Arduino
LCD_RS is CHIP_SELECT to pin 10 of Ardiono
LCD_RST is RESET to pin 8 of Arduino

Hardware SPI
U8G2_ST7920_128X64_F_HW_SPI u8g2(U8G2_R0, /* CS=/ 10, / reset=*/ 8);
LCD_RS is CHIP_SELECT to Arduino pin 10
LCD_RST is RESET to pin 8 of Arduino
LCD_E is CLOCK to pin 52 of Arduino ATMEGA2560 (you may check for UNO pin)
LCD_RW is DATA_INTO_LCD (MOSI of Arduino) to pin 51 of Arduino ATMEGA2560 (you may check for UNO pin)

Parallel 8 bits 8080 mode
//U8G2_ST7920_128X64_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /enable=/ 18 /* A4 /, E /cs=/ U8X8_PIN_NONE,
/dc/rs=/ 17 / A3 /, RS /reset=/ 15 / A1 */); // Remember to set R/W to 0

LCD_DB7 to Arduino pin 8
LCD_DB6 to Arduino pin 9
LCD_DB5 to Arduino pin 10
LCD_DB4 to Arduino pin 11
LCD_DB3 to Arduino pin 4
LCD_DB2 to Arduino pin 5
LCD_DB1 to Arduino pin 6
LCD_DB0 to Arduino pin 7

LCD_E is ENABLE to Arduino pin 18
LCD_RS is CHIP_SELECT to Arduino pin 17
LCD_RST is RESET to Arduino pin 15
LCD_RW is READ/nWRITE to Ground (Ground is WRITE for nWrite line, negative_WRITE)

[olikraus]

Thanks for testing all these modes.