Zoltan Hudak / Mbed OS LCD_McuFriend_FSMC_STM32F407

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

Diff: UniGraphic/Inits/IST3020.h

Revision:
0:fa952828e34c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UniGraphic/Inits/IST3020.h	Sun May 10 10:44:31 2020 +0000
@@ -0,0 +1,58 @@
+#ifndef MBED_IST3020_H
+#define MBED_IST3020_H
+
+
+
+#include "mbed.h"
+#include "LCD.h"
+
+/** Class for IST3020 display controller
+* to be copypasted and adapted for other controllers
+*/
+class IST3020 : public LCD
+{
+ 
+ public:
+
+    /** Create a PAR display interface
+    * @param displayproto only supports PAR_8
+    * @param port GPIO port name to use
+    * @param CS pin connected to CS of display
+    * @param reset pin connected to RESET of display
+    * @param DC pin connected to data/command of display
+    * @param WR pin connected to SDI of display
+    * @param RD pin connected to RS of display
+    * @param name The name used by the parent class to access the interface
+    * @param LCDSIZE_X x size in pixel - optional
+    * @param LCDSIZE_Y y size in pixel - optional
+    */ 
+    IST3020(proto_t displayproto, PortName port, PinName CS, PinName reset, PinName DC, PinName WR, PinName RD, const char* name, unsigned int LCDSIZE_X = 192, unsigned  int LCDSIZE_Y = 64);
+  
+    /** Create an SPI display interface
+    * @param displayproto SPI_8 or SPI_16
+    * @param Hz SPI speed in Hz
+    * @param mosi SPI pin
+    * @param miso SPI pin
+    * @param sclk SPI pin
+    * @param CS pin connected to CS of display
+    * @param reset pin connected to RESET of display
+    * @param DC pin connected to data/command of display
+    * @param name The name used by the parent class to access the interface
+    * @param LCDSIZE_X x size in pixel - optional
+    * @param LCDSIZE_Y y size in pixel - optional
+    */ 
+    IST3020(proto_t displayproto, int Hz, PinName mosi, PinName miso, PinName sclk, PinName CS, PinName reset, PinName DC, const char* name, unsigned int LCDSIZE_X = 192, unsigned  int LCDSIZE_Y = 64);
+  
+
+  
+protected:
+    
+    
+    /** Init command sequence  
+    */
+    void init();
+
+
+
+};
+#endif
\ No newline at end of file