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[pravin]

Hi , i bought FT812 display few days before and wants to communicate with over SPI. I am using freescale MK22FX512VLL12 controller.

 I am not able to  read chip id( 0x7c ).Always getting 0 in RX Buffer

Please help me to work this,

I am referring FT800 sample code and i have also changed REG_ADD according to FT81XX DATASHEET

My code is:

        SpiHostCommand(FT_GPU_EXTERNAL_OSC);
   Delay(1);
   SpiHostCommand(FT_GPU_ACTIVE_M);
   Delay(1);
   SpiHostCommand(FT_GPU_PLL_48M);          //  Ensure configured to 48 MHz
   Delay(1);
   SpiHostCommand(FT_GPU_CORE_RESET);     // Reset the core     
   Delay(1);
   SpiHostCommand(FT_GPU_ACTIVE_M);
        Delay(1);       
       chipid = 0x00;                                  // Read the Chip ID to check comms with the FT800 - should be 0x7C
   while(chipid != 0x7C){
      SpiSendAddresstoLcd(REG_ID); // REG_ID   302000h
      chipid = SpiReadLcd();  // Read the actual value
   }

 
void SpiHostCommand(unsigned char  HostCommand)
{
   unsigned char SentData;
   PORT_LCD_CS1B &= ~GPIO_PDOR_PDO(GPIO_PIN(LCD_CS1B));
   SentData=(HostCommand & 0x3F | 0x40 );
   SPI_Send_byteToLcd(SentData);
   SentData=0x00;
   SPI_Send_byteToLcd(SentData);
   SentData=0x00;
   SPI_Send_byteToLcd(SentData);
   PORT_LCD_CS1B |= GPIO_PDOR_PDO(GPIO_PIN(LCD_CS1B));
   
}

void SpiSendAddresstoLcd(unsigned long Memory_Address)///read data from memory address
{
   unsigned char SPI_Writebyte;
   
   PORT_LCD_CS1B &= ~GPIO_PDOR_PDO(GPIO_PIN(LCD_CS1B));
   SPI_Writebyte = ((Memory_Address & 0x00FF0000) >> 16);  // Mask off the first byte to send
   SPI_Writebyte = (SPI_Writebyte & 0x3F);                 // Since this is a read, the upper two bits are forced to 00
   SPI_Send_byteToLcd(SPI_Writebyte);                       // Call the low-level SPI routine for this MCU to send this byte
      
   SPI_Writebyte = ((Memory_Address & 0x0000FF00) >> ;   // Mask off the next byte to be sent
   SPI_Send_byteToLcd(SPI_Writebyte);                       // Call the low-level SPI routine for this MCU to send this byte

   SPI_Writebyte = (Memory_Address & 0x000000FF);          // Mask off the next byte to be sent (least significant byte)
   SPI_Send_byteToLcd(SPI_Writebyte);                       // Call the low-level SPI routine for this MCU to send this byte
                  
       // Send dummy 00 as required in the FT800 datasheet when doing a read
   SPI_Writebyte = 0x00;                                   // Write dummy byte of 0
   SPI_Send_byteToLcd(SPI_Writebyte);                       //

}

unsigned char SpiReadLcd()
{
   unsigned char Data=0x00;
   
   Data=SPI_Receive_byteFromLcd();
   PORT_LCD_CS1B |= GPIO_PDOR_PDO(GPIO_PIN(LCD_CS1B));
   return Data;
   
}

[FTDI Community]

Hello,

The following start-up sequence should be used with the FT81X, please note the 500ms delay at start-up:

Code: [Select]

    MCU_PDlow();                                                                // PD low to reset device                                                               
    MCU_Delay_20ms();
    MCU_PDhigh();                                                               // PD high again
    MCU_Delay_20ms();

    // ---------------------- Optional clock configuration ---------------------   

    // Un-comment this line if using external crystal. Leave commented if using internal oscillator.
    // Note that most FTDI/BRT modules based on FT800/FT801 use an external crystal
    // EVE_CmdWrite(0x44, 0x00);           // 0x44 = HostCMD_CLKEXT

    // You can also send the host command to set the PLL here if you want to change it from the default
    // of 48MHz (FT80x) or 60MHz (FT81x)
    // The command would be called here before the Active command wakes up the device   
   
    // ---------- Wake FT8xx and delay to allow device to start-up -------------   
   
    EVE_CmdWrite(FT81x_ACTIVE, 0x00);                                           // Sends 00 00 00 to wake FT8xx
    MCU_Delay_500ms();                                                          // 500ms delay (EVE requires at least 300ms here))
   
    // --------------- Check that FT8xx ready and SPI comms OK -----------------
   
    while (EVE_MemRead8(REG_ID) != 0x7C)                                        // Read REG_ID register (0x302000) until reads 0x7C
    {
    }
     
    while (EVE_MemRead8(REG_CPURESET) != 0x00)                                  // Ensure CPUreset register reads 0 and so FT8xx is ready   
    {
    }

    // ------------------------- Display settings ------------------------------

    // WQVGA display parameters
    lcdWidth   = 800;                                                           // Active width of LCD display
    lcdHeight  = 480;                                                           // Active height of LCD display
    lcdHcycle  = 928;                                                           // Total number of clocks per line
    lcdHoffset = 88;                                                            // Start of active line
    lcdHsync0  = 0;                                                             // Start of horizontal sync pulse
    lcdHsync1  = 48;                                                            // End of horizontal sync pulse
    lcdVcycle  = 525;                                                           // Total number of lines per screen
    lcdVoffset = 32;                                                            // Start of active screen
    lcdVsync0  = 0;                                                             // Start of vertical sync pulse
    lcdVsync1  = 3;                                                             // End of vertical sync pulse
    lcdPclk    = 2;                                                             // Pixel Clock
    lcdSwizzle = 0;                                                             // Define RGB output pins
    lcdPclkpol = 1;                                                             // Define active edge of PCLK
                     
    EVE_MemWrite16(REG_HSIZE,   lcdWidth);     
    EVE_MemWrite16(REG_HCYCLE,  lcdHcycle);     
    EVE_MemWrite16(REG_HOFFSET, lcdHoffset);   
    EVE_MemWrite16(REG_HSYNC0,  lcdHsync0);     
    EVE_MemWrite16(REG_HSYNC1,  lcdHsync1);     
    EVE_MemWrite16(REG_VSIZE,   lcdHeight);     
    EVE_MemWrite16(REG_VCYCLE,  lcdVcycle);     
    EVE_MemWrite16(REG_VOFFSET, lcdVoffset);   
    EVE_MemWrite16(REG_VSYNC0,  lcdVsync0);     
    EVE_MemWrite16(REG_VSYNC1,  lcdVsync1);     
    EVE_MemWrite8(REG_SWIZZLE,  lcdSwizzle);   
    EVE_MemWrite8(REG_PCLK_POL, lcdPclkpol);   
 
    FT81x_GPIO = EVE_MemRead8(REG_GPIO);                                        // Read the  GPIO register for a read/modify/write operation
    FT81x_GPIO = FT81x_GPIO | 0x80;                                             // set bit 7 of  GPIO register (DISP) - others are inputs
   EVE_MemWrite8(REG_GPIO, FT81x_GPIO);                                        // Enable the DISP signal to the LCD panel
   
    // Can move these 2 lines to after the first display list to make the start-up appear cleaner to the user
    EVE_MemWrite8(REG_PCLK, lcdPclk);                                           // Now start clocking data to the LCD panel
    EVE_MemWrite8(REG_PWM_DUTY, 127);
   
    // ---------------------- Touch and Audio settings -------------------------

    EVE_MemWrite16(REG_TOUCH_RZTHRESH, 1200);                                   // Eliminate any false touches

    EVE_MemWrite8(REG_VOL_PB, ZERO);                                            // turn recorded audio volume down
    EVE_MemWrite8(REG_VOL_SOUND, ZERO);                                         // turn synthesizer volume down
    EVE_MemWrite16(REG_SOUND, 0x6000);                                          // set synthesizer to mute

    // ----------------- First Display List to clear screen --------------------

    ramDisplayList = RAM_DL;                                                    // start of Display List
    EVE_MemWrite32(ramDisplayList, 0x02000000);                                 // Clear Color RGB sets the colour to clear screen to black

    ramDisplayList += 4;                                                        // point to next location
    EVE_MemWrite32(ramDisplayList, (0x26000000 | 0x00000007));                  // Clear 00100110 -------- -------- -----CST  (C/S/T define which parameters to clear)

    ramDisplayList += 4;                                                        // point to next location
    EVE_MemWrite32(ramDisplayList, 0x00000000);                                 // DISPLAY command 00000000 00000000 00000000 00000000 (end of display list)

    EVE_MemWrite32(REG_DLSWAP, DLSWAP_FRAME);                                   // Swap display list to make the edited one active


Please note that the Freescale samples are for the FT800 and not the FT81X, as such you should ensure you have the correct header files in your project. You can find the updated header files in our main SampleApp at the following:
https://www.ftdichip.com/Support/SoftwareExamples/FT800_Projects.htm

Best Regards,
FTDI Community

[pravin]

Thanks for reply,

Now, I am able to read chip id from FT81x. But Back light is not turning  ON ; before it was turning  ON during making PD_PIN as a OUTPUT then set to LOW.

can you please explain what is the condition to make Back light  turn ON.

It will help me to understand the Display functionality

I have also tried an example of FTDI to display screen But fails to do that.

Please help,


My code:

void ApplicationScreen1()
{
      
   ramDisplayList=RAM_DL+0;
   FT800_SPI_SendAddressWR(ramDisplayList);            // Write first entry in Display List (first location in DL Ram)
   FT800_SPI_Write32(0x02000000);                  // Clear Color RGB   00000010 BBBBBBBB GGGGGGGG RRRRRRRR  (B/G/R = Colour values)   
   // Clear the Colour, Stencil and Tag buffers. This will set the screen to the 'clear' colour set above.
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);            // Write next entry in display list (each command is 4 bytes)
   FT800_SPI_Write32(BEGIN(BITMAPS));                  // Clear 00100110 -------- -------- -----CST  (C/S/T define which parameters to clear)
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);            
   FT800_SPI_Write32(VERTEX2II(220,110,31,'F'));
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);            
   FT800_SPI_Write32(VERTEX2II(220,110,31,'T'));
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);            
   FT800_SPI_Write32(VERTEX2II(220,110,31,'D'));
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);            
   FT800_SPI_Write32(VERTEX2II(220,110,31,'I'));
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);
   FT800_SPI_Write32(ENDP());
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);
   FT800_SPI_Write32(COLOR_RGB(160,22,22)); //SET COLOUR TO RED
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);
   FT800_SPI_Write32(POINT_SIZE(320)); //SET POINT SIZE TO 20 PIXELS IN RADIUS
   
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);
   FT800_SPI_Write32(BEGIN(FTPOINTS)); //START DRAWING POINTS
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);            
   FT800_SPI_Write32(VERTEX2II(192,133,0,0));//RED COLOUR
   
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);
   FT800_SPI_Write32(ENDP());
   ramDisplayList +=4;
   FT800_SPI_SendAddressWR(ramDisplayList);
   FT800_SPI_Write32(DISPLAY());//display image
      
   FT800_SPI_SendAddressWR(REG_DLSWAP);            // Writing to the DL_SWAP register...value 10 means render after last frame complete       
   FT800_SPI_Write32(0x00000002);                  // 00000000 00000000 00000000 000000SS  (SS bits define when render occurs)
}
 

[FTDI Community]

Hello,

The backlight is controlled by the following registers:

• REG_PWM_HZ
• REG_PWM_DUTY

Depending on which module you are using you may also need to toggle an GPIO pin to enable the displays backlight.

Best Regards,
FTDI Community

[HoltRead]

Hello...I used this kind of connection to emulate a long cable with some disturbs, because the final machine should have the display fixed on cover of openable electric box and the electronic device fixed inside the box, with a 20-30cm cable.

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