3.5" inch TFT LCD Display Module 480X320 driven with FSMC.

TFT LCD Display Module 480X320 driven with FSMC

I have recently bought a 3.5" inch TFT LCD Touch Screen Display Module 480X320 with a www.mcufriend.com label on the back side. The display was equipped with an 8bit parallel interface. First I decided to test it with the UniGraphic library using the BUS_8 protocol. The display was very slow but improved when I switched to the PAR_8 protocol. Because I heard about the possibility to use a Flexible Static Memory Controller (FSMC), built into some STM MCU's, to drive LCD's (read/write to LCD's memory rather than to an external SRAM) I thought it would be a fun to try it out.

https://os.mbed.com/media/uploads/hudakz/lcd_3.5_tft_480x320_mcufriend_front.png

Below is the brief story of what I did:

  • Selected FSMC in the Connectivity category and configured it as below: https://os.mbed.com/media/uploads/hudakz/arch_max_fsmc_conf.png
  • Let the STM32CubeIDE generate the code (files).
  • Created a new program for the Seeed Arch Max target in the Mbed Online Compiler by selecting a mbed os blinky template.
  • Replaced the main.cpp with the main.c content of the STM32CubeIDE project.
  • Copy & Pasted the other files with codes from the STM32CubeIDE project to the online compiler project.
  • Renamed and modified:
    "stm32f4xx_it.h" to "stm32f4xx_it_msp.h"
    "stm32f4xx_it.c" to "stm32f4xx_it_msp.c"
  • Added the UniGraphic library to the online compiler project.
  • Extended the UniGraphic library with a FSMC_8 protocol and replaced the TFT::set_orientation(int orient) function with the one used by mcufriend for arduino.
  • Modified the main.cpp as needed.
https://os.mbed.com/media/uploads/hudakz/stm32f407vet6_st-link03.pnghttps://os.mbed.com/media/uploads/hudakz/lcd_3.5_tft_480x320_mcufriend_back.png


Wiring

STM32F407VETFT LCD module
+3.3V3V3
GNDGND
PB_12LCD_RST
GNDLCD_CS
PD_13 (RS)LCD_RS
PD_5 (WR)LCD_WR
PD_4 (RD)LCD_RD
PD_14 (DB00)LCD_D0
PD_15 (DB01)LCD_D1
PD_0 (DB02)LCD_D2
PD_1 (DB03)LCD_D3
PE_7 (DB04)LCD_D4
PE_8 (DB05)LCD_D5
PE_9 (DB06)LCD_D6
PE_10 (DB07)LCD_D7



Results
Execution times
Used protocolBUS_8FSMC_8
Operation \ Timemsms
Clear2283.98038.454
Plot192.06611.365
8bit BMP63.80541.338
Large Font163.8727.895
Sparce pixels2072.265/1458.05174.107/52.168
16bit BMP2288.58959.904
Revision:
0:fa952828e34c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UniGraphic/Inits/SSD1306.cpp	Sun May 10 10:44:31 2020 +0000
@@ -0,0 +1,188 @@
+/* mbed UniGraphic library - Device specific class
+ * Copyright (c) 2015 Peter Drescher
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+  
+#include "Protocols.h"
+#include "SSD1306.h"
+
+//////////////////////////////////////////////////////////////////////////////////
+// display settings ///////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////
+
+
+#define IC_X_SEGS    128 // UC1608 SEG has range 0-239 (239-0 if MX=1), check your datasheet, important for the orientation
+#define IC_Y_COMS    64  // UC1608 COM has range 0-127 (127-0 if MY=1), check your datasheet, important for the orientation
+
+#define SSD1306_SETCONTRAST         0x81
+#define SSD1306_DISPLAYALLON_RESUME 0xA4
+#define SSD1306_DISPLAYALLON        0xA5
+#define SSD1306_NORMALDISPLAY       0xA6
+#define SSD1306_INVERTDISPLAY       0xA7
+#define SSD1306_DISPLAYOFF          0xAE
+#define SSD1306_DISPLAYON           0xAF
+#define SSD1306_SETDISPLAYOFFSET    0xD3
+#define SSD1306_SETCOMPINS          0xDA
+#define SSD1306_SETVCOMDETECT       0xDB
+#define SSD1306_SETDISPLAYCLOCKDIV  0xD5
+#define SSD1306_SETPRECHARGE        0xD9
+#define SSD1306_SETMULTIPLEX        0xA8
+#define SSD1306_SETLOWCOLUMN        0x00
+#define SSD1306_SETHIGHCOLUMN       0x10
+#define SSD1306_SETSTARTLINE        0x40
+#define SSD1306_MEMORYMODE          0x20
+#define SSD1306_COMSCANINC          0xC0
+#define SSD1306_COMSCANDEC          0xC8
+#define SSD1306_SEGREMAP            0xA0
+#define SSD1306_CHARGEPUMP          0x8D
+
+SSD1306::SSD1306(proto_t displayproto, PortName port, PinName CS, PinName reset, PinName DC, PinName WR, PinName RD, const char *name , unsigned int LCDSIZE_X, unsigned  int LCDSIZE_Y)
+    : LCD(displayproto, port, CS, reset, DC, WR, RD, LCDSIZE_X, LCDSIZE_Y, IC_X_SEGS, IC_Y_COMS, name)
+{
+    hw_reset();
+    BusEnable(true);
+    init();
+    cls();
+    set_orientation(1);
+    locate(0,0);
+}
+SSD1306::SSD1306(proto_t displayproto, int Hz, PinName mosi, PinName miso, PinName sclk, PinName CS, PinName reset, PinName DC, const char *name, unsigned int LCDSIZE_X, unsigned  int LCDSIZE_Y)
+    : LCD(displayproto, Hz, mosi, miso, sclk, CS, reset, DC, LCDSIZE_X, LCDSIZE_Y, IC_X_SEGS, IC_Y_COMS, name)
+{
+    hw_reset();
+    BusEnable(true);
+    init();
+    cls();
+    set_orientation(1);
+    locate(0,0);
+}
+
+SSD1306::SSD1306(proto_t displayproto, int Hz, int address, PinName sda, PinName scl, const char* name , unsigned int LCDSIZE_X, unsigned  int LCDSIZE_Y)
+    : LCD(displayproto, Hz, address, sda, scl, LCDSIZE_X, LCDSIZE_Y, IC_X_SEGS, IC_Y_COMS, name)
+{
+    init();
+    cls();
+    set_orientation(1);
+    locate(0,0);
+}
+
+
+// reset and init the lcd controller
+void SSD1306::init()
+{
+    /* Start Initial Sequence ----------------------------------------------------*/
+    
+  //  wr_cmd8(0xE2);   //  sw reset
+    wait_ms(15);
+    
+    wr_cmd8(SSD1306_DISPLAYOFF);    // no problem in SPI_16 for single byte cmds
+    wr_cmd16((SSD1306_SETDISPLAYCLOCKDIV<<8)|0x80);   // wr_cmd16 for multibyte cmds issue in SPI16 mode
+  //  wr_cmd8(0x80); // in SPI_16 it would become 0xE380 and will break things up
+    wr_cmd16((SSD1306_SETMULTIPLEX<<8)|63);
+ //   wr_cmd8(63);
+    
+    wr_cmd16((SSD1306_SETDISPLAYOFFSET<<8)|0x00);
+ //   wr_cmd8(0x0);
+    
+    wr_cmd8(SSD1306_SETSTARTLINE | 0x0);            // line #0
+
+    wr_cmd16((SSD1306_CHARGEPUMP<<8)|0x14);
+  //  wr_cmd8(0x14);                         // 0x10 
+
+    wr_cmd16((SSD1306_MEMORYMODE<<8)|0x00);
+ //   wr_cmd8(0x00);                                  // 0x0 act like ks0108
+
+    wr_cmd8(SSD1306_SEGREMAP ); //| 0x1);
+
+    wr_cmd8(SSD1306_COMSCANDEC);
+
+    wr_cmd16((SSD1306_SETCOMPINS<<8)|0x12);
+  //  wr_cmd8(0x12);                           //        LCDSIZE_Y == 32 ? 0x02 : 0x12);        
+
+    wr_cmd16((SSD1306_SETCONTRAST<<8)|0xCF);
+ //   wr_cmd8(0xCF);                              //  _rawHeight == 32 ? 0x8F : ((vccstate == SSD1306_EXTERNALVCC) ? 0x9F : 0xCF) );
+
+    wr_cmd16((SSD1306_SETPRECHARGE<<8)|0xF1);
+ //   wr_cmd8(0xF1);                               // : 0x22);
+
+    wr_cmd16((SSD1306_SETVCOMDETECT<<8)|0x40);
+ //   wr_cmd8(0x40);
+
+    wr_cmd8(SSD1306_DISPLAYALLON_RESUME);
+
+    //wr_cmd8(SSD1306_NORMALDISPLAY);
+    wr_cmd8(SSD1306_INVERTDISPLAY);
+    
+    wr_cmd8(SSD1306_DISPLAYON);
+}
+
+////////////////////////////////////////////////////////////////////
+// functions that overrides the standard ones implemented in LCD.cpp
+////////////////////////////////////////////////////////////////////
+
+void SSD1306::mirrorXY(mirror_t mode)
+{
+    switch (mode)
+    {
+        case(NONE):
+            wr_cmd16(0xA0C0); 
+            break;
+        case(X):
+            wr_cmd16(0xA1C0);
+            break;
+        case(Y):
+            wr_cmd16(0xA0C8);
+            break;
+        case(XY):
+            wr_cmd16(0xA1C8);
+            break;
+    }
+}
+
+void SSD1306::set_contrast(int o)
+{
+    contrast = o;
+  
+    wr_cmd16(0x8100|(o&0xFF));
+}
+
+////////////////////////////////////////////////////////////////////
+// functions that overrides the standard ones implemented in LCD.cpp
+////////////////////////////////////////////////////////////////////
+
+
+const uint8_t scroll_speed[8]={3,2,1,6,0,5,4,7};
+
+////////////////////////////////////////////////////////////////////
+// functions addon  to LCD.cpp
+////////////////////////////////////////////////////////////////////
+void SSD1306::horizontal_scroll(int l_r,int s_page,int e_page,int speed){
+    wr_cmd8(0x2E);                      // deactivate scroll before change
+    if(l_r == 1){
+        wr_cmd16(0x2700);               // horizontal scroll left
+    }
+    else {
+        wr_cmd16(0x2600);
+    }
+    wr_cmd16((s_page & 0x07)<<8 | (scroll_speed[speed & 0x07]));
+    wr_cmd16((e_page & 0x07)<<8 );
+    wr_cmd16(0xFF2F);
+}
+
+void SSD1306::horiz_vert_scroll(int l_r,int s_page,int e_page,int v_off,int speed){
+    wr_cmd8(0x2E);                      // deactivate scroll before change
+    if(l_r == 1){
+            wr_cmd16(0x2A00);               // horizontal scroll left
+        }
+        else {
+            wr_cmd16(0x2900);
+        }
+        wr_cmd16((s_page & 0x07)<<8 | (scroll_speed[speed & 0x07]));
+        wr_cmd16((e_page & 0x07)<<8 | (v_off & 0x3F) );
+        wr_cmd8(0x2F);
+
+}
+
+void SSD1306::end_scroll(){
+    wr_cmd8(0x2E);
+}