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/Protocols/SPI16.h@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 #ifndef SPI16_H
hudakz 0:fa952828e34c 2 #define SPI16_H
hudakz 0:fa952828e34c 3
hudakz 0:fa952828e34c 4 #define NDEBUG // avoid MBED_ASSERT to halt process when PinName DC==NC
hudakz 0:fa952828e34c 5
hudakz 0:fa952828e34c 6 #include "mbed.h"
hudakz 0:fa952828e34c 7 #include "Protocols.h"
hudakz 0:fa952828e34c 8 //#include "GraphicsDisplay.h"
hudakz 0:fa952828e34c 9
hudakz 0:fa952828e34c 10 /** SPI 16bit interface
hudakz 0:fa952828e34c 11 */
hudakz 0:fa952828e34c 12 class SPI16 : public Protocols
hudakz 0:fa952828e34c 13 {
hudakz 0:fa952828e34c 14 public:
hudakz 0:fa952828e34c 15
hudakz 0:fa952828e34c 16 /** Create an SPI 8bit display interface with 3 control pins
hudakz 0:fa952828e34c 17 *
hudakz 0:fa952828e34c 18 * @param SPI mosi
hudakz 0:fa952828e34c 19 * @param SPI miso
hudakz 0:fa952828e34c 20 * @param SPI sclk
hudakz 0:fa952828e34c 21 * @param CS pin connected to CS of display
hudakz 0:fa952828e34c 22 * @param reset pin connected to RESET of display
hudakz 0:fa952828e34c 23 * @param DC pin connected to data/command of display
hudakz 0:fa952828e34c 24 */
hudakz 0:fa952828e34c 25 SPI16(int Hz, PinName mosi, PinName miso, PinName sclk, PinName CS, PinName reset, PinName DC=NC);
hudakz 0:fa952828e34c 26
hudakz 0:fa952828e34c 27 protected:
hudakz 0:fa952828e34c 28
hudakz 0:fa952828e34c 29 /** Send 8bit command to display controller
hudakz 0:fa952828e34c 30 *
hudakz 0:fa952828e34c 31 * @note switches spi format 16->8->16, better use wr_cmd16 with NOP in front
hudakz 0:fa952828e34c 32 * @param cmd: byte to send
hudakz 0:fa952828e34c 33 *
hudakz 0:fa952828e34c 34 */
hudakz 0:fa952828e34c 35 virtual void wr_cmd8(unsigned char cmd);
hudakz 0:fa952828e34c 36
hudakz 0:fa952828e34c 37 /** Send 8bit data to display controller
hudakz 0:fa952828e34c 38 *
hudakz 0:fa952828e34c 39 * @note switches spi format 16->8->16, better use wr_data16 with repeated byte (if does not hurt)
hudakz 0:fa952828e34c 40 * @param data: byte to send
hudakz 0:fa952828e34c 41 *
hudakz 0:fa952828e34c 42 */
hudakz 0:fa952828e34c 43 virtual void wr_data8(unsigned char data);
hudakz 0:fa952828e34c 44
hudakz 0:fa952828e34c 45 /** Send 2x8bit command to display controller
hudakz 0:fa952828e34c 46 *
hudakz 0:fa952828e34c 47 * @param cmd: halfword to send
hudakz 0:fa952828e34c 48 * @note in SPI_16 mode a single 16bit transfer will be done
hudakz 0:fa952828e34c 49 */
hudakz 0:fa952828e34c 50 virtual void wr_cmd16(unsigned short cmd);
hudakz 0:fa952828e34c 51
hudakz 0:fa952828e34c 52 /** Send 2x8bit data to display controller
hudakz 0:fa952828e34c 53 *
hudakz 0:fa952828e34c 54 * @param data: halfword to send
hudakz 0:fa952828e34c 55 * @note in SPI_16 mode a single 16bit transfer will be done
hudakz 0:fa952828e34c 56 */
hudakz 0:fa952828e34c 57 virtual void wr_data16(unsigned short data);
hudakz 0:fa952828e34c 58
hudakz 0:fa952828e34c 59 /** Send 16bit pixeldata to display controller
hudakz 0:fa952828e34c 60 *
hudakz 0:fa952828e34c 61 * @param data: halfword to send
hudakz 0:fa952828e34c 62 *
hudakz 0:fa952828e34c 63 */
hudakz 0:fa952828e34c 64 virtual void wr_gram(unsigned short data);
hudakz 0:fa952828e34c 65
hudakz 0:fa952828e34c 66 /** Send same 16bit pixeldata to display controller multiple times
hudakz 0:fa952828e34c 67 *
hudakz 0:fa952828e34c 68 * @param data: halfword to send
hudakz 0:fa952828e34c 69 * @param count: how many
hudakz 0:fa952828e34c 70 *
hudakz 0:fa952828e34c 71 */
hudakz 0:fa952828e34c 72 virtual void wr_gram(unsigned short data, unsigned int count);
hudakz 0:fa952828e34c 73
hudakz 0:fa952828e34c 74 /** Send array of pixeldata shorts to display controller
hudakz 0:fa952828e34c 75 *
hudakz 0:fa952828e34c 76 * @param data: unsigned short pixeldata array
hudakz 0:fa952828e34c 77 * @param lenght: lenght (in shorts)
hudakz 0:fa952828e34c 78 *
hudakz 0:fa952828e34c 79 */
hudakz 0:fa952828e34c 80 virtual void wr_grambuf(unsigned short* data, unsigned int lenght);
hudakz 0:fa952828e34c 81
hudakz 0:fa952828e34c 82 /** Read 16bit pixeldata from display controller (with dummy cycle)
hudakz 0:fa952828e34c 83 *
hudakz 0:fa952828e34c 84 * @param convert true/false. Convert 18bit to 16bit, some controllers returns 18bit
hudakz 0:fa952828e34c 85 * @returns 16bit color
hudakz 0:fa952828e34c 86 */
hudakz 0:fa952828e34c 87 virtual unsigned short rd_gram(bool convert);
hudakz 0:fa952828e34c 88
hudakz 0:fa952828e34c 89 /** Read 4x8bit register data (with dummy cycle)
hudakz 0:fa952828e34c 90 * @param reg the register to read
hudakz 0:fa952828e34c 91 * @returns data as uint
hudakz 0:fa952828e34c 92 *
hudakz 0:fa952828e34c 93 */
hudakz 0:fa952828e34c 94 virtual unsigned int rd_reg_data32(unsigned char reg);
hudakz 0:fa952828e34c 95
hudakz 0:fa952828e34c 96 /** Read 3x8bit ExtendedCommands register data
hudakz 0:fa952828e34c 97 * @param reg the register to read
hudakz 0:fa952828e34c 98 * @param SPIreadenablecmd vendor/device specific cmd to read EXTC registers
hudakz 0:fa952828e34c 99 * @returns data as uint
hudakz 0:fa952828e34c 100 * @note EXTC regs (0xB0 to 0xFF) are read/write registers but needs special cmd to be read in SPI mode
hudakz 0:fa952828e34c 101 */
hudakz 0:fa952828e34c 102 virtual unsigned int rd_extcreg_data32(unsigned char reg, unsigned char SPIreadenablecmd);
hudakz 0:fa952828e34c 103
hudakz 0:fa952828e34c 104 /** ILI932x specific, does a dummy read cycle, number of bits is protocol dependent
hudakz 0:fa952828e34c 105 * for PAR protocols: a signle RD bit toggle
hudakz 0:fa952828e34c 106 * for SPI8: 8clocks
hudakz 0:fa952828e34c 107 * for SPI16: 16 clocks
hudakz 0:fa952828e34c 108 */
hudakz 0:fa952828e34c 109 virtual void dummyread ();
hudakz 0:fa952828e34c 110
hudakz 0:fa952828e34c 111 /** ILI932x specific, select register for a successive write or read
hudakz 0:fa952828e34c 112 *
hudakz 0:fa952828e34c 113 * @param reg register to be selected
hudakz 0:fa952828e34c 114 * @param forread false = a write next (default), true = a read next
hudakz 0:fa952828e34c 115 * @note forread only used by SPI protocols
hudakz 0:fa952828e34c 116 */
hudakz 0:fa952828e34c 117 virtual void reg_select(unsigned char reg, bool forread =false);
hudakz 0:fa952828e34c 118
hudakz 0:fa952828e34c 119 /** ILI932x specific, write register with data
hudakz 0:fa952828e34c 120 *
hudakz 0:fa952828e34c 121 * @param reg register to write
hudakz 0:fa952828e34c 122 * @param data 16bit data
hudakz 0:fa952828e34c 123 */
hudakz 0:fa952828e34c 124 virtual void reg_write(unsigned char reg, unsigned short data);
hudakz 0:fa952828e34c 125
hudakz 0:fa952828e34c 126 /** ILI932x specific, read register
hudakz 0:fa952828e34c 127 *
hudakz 0:fa952828e34c 128 * @param reg register to be read
hudakz 0:fa952828e34c 129 * @returns 16bit register value
hudakz 0:fa952828e34c 130 */
hudakz 0:fa952828e34c 131 virtual unsigned short reg_read(unsigned char reg);
hudakz 0:fa952828e34c 132
hudakz 0:fa952828e34c 133 /** HW reset sequence (without display init commands)
hudakz 0:fa952828e34c 134 */
hudakz 0:fa952828e34c 135 virtual void hw_reset();
hudakz 0:fa952828e34c 136
hudakz 0:fa952828e34c 137 /** Set ChipSelect high or low
hudakz 0:fa952828e34c 138 * @param enable 0/1
hudakz 0:fa952828e34c 139 */
hudakz 0:fa952828e34c 140 virtual void BusEnable(bool enable);
hudakz 0:fa952828e34c 141
hudakz 0:fa952828e34c 142 DigitalOut _CS;
hudakz 0:fa952828e34c 143
hudakz 0:fa952828e34c 144 private:
hudakz 0:fa952828e34c 145
hudakz 0:fa952828e34c 146 SPI _spi;
hudakz 0:fa952828e34c 147 DigitalOut _reset;
hudakz 0:fa952828e34c 148 DigitalOut _DC;
hudakz 0:fa952828e34c 149
hudakz 0:fa952828e34c 150 };
hudakz 0:fa952828e34c 151 #endif