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

UniGraphic/Inits/IST3020.cpp

Committer:
hudakz
Date:
2020-09-25
Revision:
1:47c996032a9e
Parent:
0:fa952828e34c

File content as of revision 1:47c996032a9e:

 /* 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 "IST3020.h"

/*this is a quite standard config, similar to ST7565, except bigger screen and diff resistor ratio value*/

//////////////////////////////////////////////////////////////////////////////////
// display settings ///////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////
#define IC_X_SEGS    256 // IST3020 SEG has range 0-255 (255-0 if ADC=1), check your datasheet, important for the orientation
#define IC_Y_COMS    64  // IST3020 COM has range 0-63 (63-0 if SHL=1), check your datasheet, important for the orientation
// put in constructor
//#define LCDSIZE_X       192 // display X pixels, IST3020 is advertised as 224x65 but display size could be smaller
//#define LCDSIZE_Y       64  // display Y pixels, the 65th is for accessing "icons"



IST3020::IST3020(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);
}
IST3020::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, 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
// init sequence is manufacturer specific
void IST3020::init()
{
    /* Start Initial Sequence ----------------------------------------------------*/
    
    wr_cmd8(0xE2);   //  sw reset
    wait_ms(10);
    
    wr_cmd8(0xAE);   //  display off
    wr_cmd8(0xAB);   //  built-in OSC on
    wr_cmd8(0xA2);   //  bias voltage (1/9)
  //  wr_cmd8(0xA3);   //  bias voltage (1/7)

    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(0x2C);   //  Internal Voltage Converter ON
    wait_ms(10);
    wr_cmd8(0x2E);   //  Internal Voltage Regulator ON
    wait_ms(10);
    wr_cmd8(0x2F);   //  Internal Voltage Follower ON
    wait_ms(10);
    wr_cmd8(0x20);   //  Regulor_Resistor_Select resistor ratio 20-27 20=4.5(default) 27=8.0, 0.5 steps
    set_contrast(46);
    //wr_cmd8(0x81);   //  set contrast (reference voltage register set)
    //wr_cmd8(0x20);   //  contrast 00-3F default 20
    
    wr_cmd8(0xA4);   //  LCD display ram (EntireDisplayOn disable)
    //wr_cmd8(0x70);   //  External Capacitors Discharge function enable (should be enabled by default)
    //wr_cmd8(0x77);   //  External Capacitors Discharge function disable
    wr_cmd8(0x40);   // start line = 0
    wr_cmd8(0xA6);     // display normal (1 = illuminated)
    wr_cmd8(0xAF);     // display ON 

}