Scrolling vertical with ILI9488

[andromeda2911]

Hi,
On driver for ILI9341, is possible to scroll vertical,

#define ILI9341_VSCRDEF 0x33 is defined on driver and
#define ILI9341_VSCRSADD 0x37

on terminal sample code for ILI9431 there is

void setupScrollArea(uint16_t tfa, uint16_t bfa) {
  tft.writecommand(ILI9341_VSCRDEF); // Vertical scroll definition
  tft.writedata(tfa >> 8);           // Top Fixed Area line count
  tft.writedata(tfa);
  tft.writedata((YMAX-tfa-bfa)>>8);  // Vertical Scrolling Area line count
  tft.writedata(YMAX-tfa-bfa);
  tft.writedata(bfa >> 8);           // Bottom Fixed Area line count
  tft.writedata(bfa);
}

// ##############################################################################################
// Setup the vertical scrolling start address pointer
// ##############################################################################################
void scrollAddress(uint16_t vsp) {
  tft.writecommand(ILI9341_VSCRSADD); // Vertical scrolling pointer
  tft.writedata(vsp>>8);
  tft.writedata(vsp);
}

but not on drivers ILI9488
i replaced on my source code this two variable 0x33 and 0x37 and it work.

// ##############################################################################################
// Setup a portion of the screen for vertical scrolling
// ##############################################################################################
// We are using a hardware feature of the display, so we can only scroll in portrait orientation
void setupScrollArea(uint16_t tfa, uint16_t bfa) {
  tft.writecommand(0x33); // Vertical scroll definition
  tft.writedata(tfa >> 8);           // Top Fixed Area line count
  tft.writedata(tfa);
  tft.writedata((YMAX-tfa-bfa)>>8);  // Vertical Scrolling Area line count
  tft.writedata(YMAX-tfa-bfa);
  tft.writedata(bfa >> 8);           // Bottom Fixed Area line count
  tft.writedata(bfa);
}

// ##############################################################################################
// Setup the vertical scrolling start address pointer
// ##############################################################################################
void scrollAddress(uint16_t vsp) {
  tft.writecommand(0x37); // Vertical scrolling pointer
  tft.writedata(vsp>>8);
  tft.writedata(vsp);
}

You will also need to change the resolution by replacing 320x240 with 480x320
and replace the value 231 with 311 for XPOS

.......
 if (data == '\r' || xPos > 311) {
      xPos = 0;
      yDraw = scroll_line(); // It can take 13ms to scroll and blank 16 pixel lines
    }
    if (data > 31 && data < 128) {
      xPos += tft.drawChar(data,xPos,yDraw,2);
      blank[(28+(yStart-TOP_FIXED_AREA)/TEXT_HEIGHT)%29]=xPos; // Keep a record of line lengths
    }
.........

You have to change blanck[19] by blank[29]
and replace values 18 byt 28 and 19 by 29

blank[(28+(yStart-TOP_FIXED_AREA)/TEXT_HEIGHT)%29]=xPos; // Keep a record of line lengths

on void Setup()

// Setup the TFT display
  tft.init();
  tft.setRotation(0); // Must be setRotation(0) for this sketch to work correctly
  tft.fillScreen(TFT_BLACK);
  
  // Setup baud rate and draw top banner
  //ss.begin(9600);
  
  tft.setTextColor(TFT_WHITE, TFT_BLUE);
  tft.fillRect(0,0,320,16, TFT_BLUE);
  tft.drawCentreString(" Serial Terminal - 115200 baud ",120,0,2);

  // Change colour for scrolling zone text
  tft.setTextColor(TFT_WHITE, TFT_BLACK);

  // Setup scroll area
  setupScrollArea(TOP_FIXED_AREA, BOT_FIXED_AREA);

  // Zero the array
  for (byte i = 0; i<28; i++) blank[i]=0;

for title at top:

 tft.fillScreen(TFT_BLACK);

  tft.setTextColor(TFT_WHITE, TFT_BLUE);
  tft.fillRect(0, 0, XMAX, TEXT_HEIGHT, TFT_BLUE);
  tft.drawCentreString(" Serial Terminal - 115200 baud ",120,0,2);

  // Change colour for scrolling zone text
  tft.setTextColor(TFT_WHITE, TFT_BLACK);

  // Setup scroll area
  setupScrollArea(TOP_FIXED_AREA, BOT_FIXED_AREA);

  // Zero the array
  for (byte i = 0; i<28; i++) blank[i]=0;

it's possible to add this two variable on drivers ILI9488 ?

Arduino 2.3.7
Waveshare Res_Touch_Screen 3.5" ILI9488
Waveshare RP2040-Plus or other

[Bodmer]

This is one of the more esoteric capabilites which I find is rearely used and it takes a bit of getting used to as the 0,0 reference moves so this causes some grief to users. I will move this to the discussions as others may find it useful.