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

UniGraphic/Inits/IST3020.cpp@0:fa952828e34c, 2020-05-10 (annotated)

Committer:
hudakz
Date:
Sun May 10 10:44:31 2020 +0000
Revision:
0:fa952828e34c
3.5" inch TFT LCD Display Module 480X320 driven with FSMC.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hudakz 0:fa952828e34c 1 /* mbed UniGraphic library - Device specific class
hudakz 0:fa952828e34c 2 * Copyright (c) 2015 Giuliano Dianda
hudakz 0:fa952828e34c 3 * Released under the MIT License: http://mbed.org/license/mit
hudakz 0:fa952828e34c 4 */
hudakz 0:fa952828e34c 5 #include "Protocols.h"
hudakz 0:fa952828e34c 6 #include "IST3020.h"
hudakz 0:fa952828e34c 7
hudakz 0:fa952828e34c 8 /*this is a quite standard config, similar to ST7565, except bigger screen and diff resistor ratio value*/
hudakz 0:fa952828e34c 9
hudakz 0:fa952828e34c 10 //////////////////////////////////////////////////////////////////////////////////
hudakz 0:fa952828e34c 11 // display settings ///////////////////////////////////////////////////////
hudakz 0:fa952828e34c 12 /////////////////////////////////////////////////////////////////////////
hudakz 0:fa952828e34c 13 #define IC_X_SEGS 256 // IST3020 SEG has range 0-255 (255-0 if ADC=1), check your datasheet, important for the orientation
hudakz 0:fa952828e34c 14 #define IC_Y_COMS 64 // IST3020 COM has range 0-63 (63-0 if SHL=1), check your datasheet, important for the orientation
hudakz 0:fa952828e34c 15 // put in constructor
hudakz 0:fa952828e34c 16 //#define LCDSIZE_X 192 // display X pixels, IST3020 is advertised as 224x65 but display size could be smaller
hudakz 0:fa952828e34c 17 //#define LCDSIZE_Y 64 // display Y pixels, the 65th is for accessing "icons"
hudakz 0:fa952828e34c 18
hudakz 0:fa952828e34c 19
hudakz 0:fa952828e34c 20
hudakz 0:fa952828e34c 21 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)
hudakz 0:fa952828e34c 22 : LCD(displayproto, port, CS, reset, DC, WR, RD, LCDSIZE_X, LCDSIZE_Y, IC_X_SEGS, IC_Y_COMS, name)
hudakz 0:fa952828e34c 23 {
hudakz 0:fa952828e34c 24 hw_reset();
hudakz 0:fa952828e34c 25 BusEnable(true);
hudakz 0:fa952828e34c 26 init();
hudakz 0:fa952828e34c 27 cls();
hudakz 0:fa952828e34c 28 set_orientation(1);
hudakz 0:fa952828e34c 29 locate(0,0);
hudakz 0:fa952828e34c 30 }
hudakz 0:fa952828e34c 31 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)
hudakz 0:fa952828e34c 32 : LCD(displayproto, Hz, mosi, miso, sclk, CS, reset, DC, LCDSIZE_X, LCDSIZE_Y, IC_X_SEGS, IC_Y_COMS, name)
hudakz 0:fa952828e34c 33 {
hudakz 0:fa952828e34c 34 hw_reset();
hudakz 0:fa952828e34c 35 BusEnable(true);
hudakz 0:fa952828e34c 36 init();
hudakz 0:fa952828e34c 37 cls();
hudakz 0:fa952828e34c 38 set_orientation(1);
hudakz 0:fa952828e34c 39 locate(0,0);
hudakz 0:fa952828e34c 40 }
hudakz 0:fa952828e34c 41 // reset and init the lcd controller
hudakz 0:fa952828e34c 42 // init sequence is manufacturer specific
hudakz 0:fa952828e34c 43 void IST3020::init()
hudakz 0:fa952828e34c 44 {
hudakz 0:fa952828e34c 45 /* Start Initial Sequence ----------------------------------------------------*/
hudakz 0:fa952828e34c 46
hudakz 0:fa952828e34c 47 wr_cmd8(0xE2); // sw reset
hudakz 0:fa952828e34c 48 wait_ms(10);
hudakz 0:fa952828e34c 49
hudakz 0:fa952828e34c 50 wr_cmd8(0xAE); // display off
hudakz 0:fa952828e34c 51 wr_cmd8(0xAB); // built-in OSC on
hudakz 0:fa952828e34c 52 wr_cmd8(0xA2); // bias voltage (1/9)
hudakz 0:fa952828e34c 53 // wr_cmd8(0xA3); // bias voltage (1/7)
hudakz 0:fa952828e34c 54
hudakz 0:fa952828e34c 55 wr_cmd8(0xA0); // ADC select seg0-seg223
hudakz 0:fa952828e34c 56 //wr_cmd8(0xA1); // ADC select seg223-seg0
hudakz 0:fa952828e34c 57 wr_cmd8(0xC8); // SHL select com63-com0
hudakz 0:fa952828e34c 58 //wr_cmd8(0xC0); // SHL select com0-com63
hudakz 0:fa952828e34c 59
hudakz 0:fa952828e34c 60 wr_cmd8(0x2C); // Internal Voltage Converter ON
hudakz 0:fa952828e34c 61 wait_ms(10);
hudakz 0:fa952828e34c 62 wr_cmd8(0x2E); // Internal Voltage Regulator ON
hudakz 0:fa952828e34c 63 wait_ms(10);
hudakz 0:fa952828e34c 64 wr_cmd8(0x2F); // Internal Voltage Follower ON
hudakz 0:fa952828e34c 65 wait_ms(10);
hudakz 0:fa952828e34c 66 wr_cmd8(0x20); // Regulor_Resistor_Select resistor ratio 20-27 20=4.5(default) 27=8.0, 0.5 steps
hudakz 0:fa952828e34c 67 set_contrast(46);
hudakz 0:fa952828e34c 68 //wr_cmd8(0x81); // set contrast (reference voltage register set)
hudakz 0:fa952828e34c 69 //wr_cmd8(0x20); // contrast 00-3F default 20
hudakz 0:fa952828e34c 70
hudakz 0:fa952828e34c 71 wr_cmd8(0xA4); // LCD display ram (EntireDisplayOn disable)
hudakz 0:fa952828e34c 72 //wr_cmd8(0x70); // External Capacitors Discharge function enable (should be enabled by default)
hudakz 0:fa952828e34c 73 //wr_cmd8(0x77); // External Capacitors Discharge function disable
hudakz 0:fa952828e34c 74 wr_cmd8(0x40); // start line = 0
hudakz 0:fa952828e34c 75 wr_cmd8(0xA6); // display normal (1 = illuminated)
hudakz 0:fa952828e34c 76 wr_cmd8(0xAF); // display ON
hudakz 0:fa952828e34c 77
hudakz 0:fa952828e34c 78 }