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/Protocols/I2C_bus.cpp

Committer:
hudakz
Date:
2020-05-10
Revision:
0:fa952828e34c

File content as of revision 0:fa952828e34c:

/* mbed UniGraphic library - I2C protocol class
 * Copyright (c) 2017 Peter Drescher
 * Released under the MIT License: http://mbed.org/license/mit
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
 
#include "I2C_bus.h"

I2C_bus::I2C_bus(int Hz, int address, PinName sda, PinName scl)
    : _i2c(sda,scl)
{
    _i2c.frequency(Hz);
    _address = address;
    //hw_reset();    
}

void I2C_bus::wr_cmd8(unsigned char cmd)
{     
    char tmp[2];
    tmp[0] = 0x00;  //command 
    tmp[1] = cmd;
    _i2c.write(_address,tmp,2);
}
void I2C_bus::wr_data8(unsigned char data)
{
    _i2c.write(data);    // write 8bit
}
void I2C_bus::wr_cmd16(unsigned short cmd)
{     
    char tmp[3];
    tmp[0] = 00; //command
    tmp[1] = cmd>>8;
    tmp[2] = cmd&0xFF;
    
    _i2c.write(_address,tmp,3);
}
void I2C_bus::wr_data16(unsigned short data)
{
    _i2c.write(data>>8);    // write 8bit
    _i2c.write(data&0xFF);    // write 8bit
}
void I2C_bus::wr_gram(unsigned short data)
{
    _i2c.write(data>>8);    // write 8bit
    _i2c.write(data&0xFF);    // write 8bit
}
void I2C_bus::wr_gram(unsigned short data, unsigned int count)
{
    _i2c.start();
    _i2c.write(_address);
    _i2c.write(0x40);          // data continue
    if((data>>8)==(data&0xFF))
    {
        count<<=1;
        while(count)
        {
            _i2c.write(data);    // write 8bit
            count--;
        }
    }
    else
    {
        while(count)
        {
            _i2c.write(data>>8);    // write 8bit
            _i2c.write(data&0xFF);    // write 8bit
            count--;
        }
    }
   _i2c.stop();
}
void I2C_bus::wr_grambuf(unsigned short* data, unsigned int lenght)
{
    _i2c.start();
    _i2c.write(_address);
    _i2c.write(0x40);          // data continue
    while(lenght)
    {
        _i2c.write((*data)>>8);    // write 8bit
        _i2c.write((*data)&0xFF);    // write 8bit
        data++;
        lenght--;
    }
    _i2c.stop();
}

void I2C_bus::hw_reset()
{
    
}
void I2C_bus::BusEnable(bool enable)
{
}

void I2C_bus::reg_select(unsigned char reg, bool forread)
{    
}

unsigned int I2C_bus::rd_reg_data32(unsigned char reg)
{
     return 0;
}

unsigned int I2C_bus::rd_extcreg_data32(unsigned char reg, unsigned char SPIreadenablecmd)
{
    return 0;
}

void I2C_bus::dummyread()
{
}

unsigned short I2C_bus::rd_gram(bool convert)
{
    return (0);    
}

unsigned short I2C_bus::reg_read(unsigned char reg)
{
    return (0);
}

void I2C_bus::reg_write(unsigned char reg, unsigned short data)
{
}