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/UC1608.cpp	Sun May 10 10:44:31 2020 +0000
@@ -0,0 +1,100 @@
+ /* mbed UniGraphic library - Device specific class
+ * Copyright (c) 2015 Giuliano Dianda
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+#include "Protocols.h"
+#include "UC1608.h"
+
+//////////////////////////////////////////////////////////////////////////////////
+// display settings ///////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////
+#define IC_X_SEGS    240 // UC1608 SEG has range 0-239 (239-0 if MX=1), check your datasheet, important for the orientation
+#define IC_Y_COMS    128  // UC1608 COM has range 0-127 (127-0 if MY=1), check your datasheet, important for the orientation
+//#define LCDSIZE_X       240 // display X pixels
+//#define LCDSIZE_Y       120  // display Y pixels, UC1608 is advertised as 240x128 but display size could be smaller
+
+
+
+UC1608::UC1608(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);
+}
+UC1608::UC1608(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);
+}
+// reset and init the lcd controller
+void UC1608::init()
+{
+    /* Start Initial Sequence ----------------------------------------------------*/
+    
+  //  wr_cmd8(0xE2);   //  sw reset
+    wait_ms(15);
+    
+    wr_cmd8(0x27);   // Multiplex rate :128   set temperature consenpation 0%
+    wr_cmd8(0xEA);   //set bias:1/12bias
+
+    wr_cmd8(0xC4);   // set mirror MX=1,MY=0 (controller->display SEGs wiring inverted)
+   // wr_cmd8(0xA0);   // ADC select seg0-seg223
+    //wr_cmd8(0xA1);   // ADC select seg223-seg0
+   // wr_cmd8(0xC8);   // SHL select com63-com0
+    //wr_cmd8(0xC0);   // SHL select com0-com63
+
+    wr_cmd8(0x2F);   //  //Power Control:internal, LCD capacitance 60nf-90nf
+    wait_ms(10);
+    
+   // wr_cmd8(0x81);//Set Gain and Potentiometer
+  //  wr_cmd8(0x40|26);//Set Gain and Potentiometer  xx xxxxxx
+    set_contrast(26);
+    
+    wr_cmd8(0x88);   //disable colum/page address wraparound
+    wr_cmd8(0xA4);   //  LCD display ram (EntireDisplayOn disable)
+    wr_cmd8(0x40);   // start line = 0
+    wr_cmd8(0xA6);     // display normal (1 = illuminated)
+    wr_cmd8(0xAF);     // display ON 
+
+}
+////////////////////////////////////////////////////////////////////
+// functions that overrides the standard ones implemented in LCD.cpp
+////////////////////////////////////////////////////////////////////
+void UC1608::mirrorXY(mirror_t mode)
+{
+    switch (mode)
+    {
+        case(NONE):
+            wr_cmd8(0xC4); // this is in real X mirror command, but my display have SEGs wired inverted, so assume this is the default no-x-mirror
+            break;
+        case(X):
+            wr_cmd8(0xC0);
+            break;
+        case(Y):
+            wr_cmd8(0xCC);
+            break;
+        case(XY):
+            wr_cmd8(0xC8);
+            break;
+    }
+}
+void UC1608::set_contrast(int o)
+{
+    contrast = o;
+  //  wr_cmd8(0x81);      //  set volume
+  //  wr_cmd8(0x40|(o&0x3F));
+    wr_cmd16(0x8140|(o&0x3F));
+}
+void UC1608::BusEnable(bool enable)
+{
+    LCD::BusEnable(!enable); // crap IC has CS not inverted (active HIGH)
+}
\ No newline at end of file