Both Scrolling and Fixed Text

[agganitk]

I want to have some text on left most side FIXED and some text keep on scrolling on remaning screen towards right.
So my display will have both Fixed and Scrolling text at same time.
But when I run dmd.stepMarquee function whole screen starts scrolling-the text I want fixed also starts scrolling with text I want to scroll.
please suggest.

[board707]

Hi
You need to use dual buffer feature.
At every step of the scrolling - first move the scrolling text and next print the fixed one above the scrolling.

[agganitk]

Can you please share some example of dual buffer feature. I am not sure how to use it.
i did like below.. good news is character 'A' stays but some LEDs just next to A character are flickering.

while(!ret){
if ((millis() - prev_step) > 150 ) {
ret=dmd.stepMarquee(1,0);

   dmd.drawChar(1, 1, 'A', GRAPHICS_NORMAL);
   prev_step=millis();
   //delay(1000);
 }

[board707]

Example sketch for fixed and scrolling text:

/*--------------------------------------------------------------------------------------
  Draw fixed and scrolling text in the same screen

  DMD_STM32a example code for STM32F103xxx board
  ------------------------------------------------------------------------------------- */
#include "DMD_RGB.h"

// Fonts includes
#include "st_fonts/Arial14.h"

//Number of panels in x and y axis
#define DISPLAYS_ACROSS 1
#define DISPLAYS_DOWN 1

// Enable of output buffering
// if true, changes only outputs to matrix after
// swapBuffers(true) command
// If dual buffer not enabled, all output draw at matrix directly
// and swapBuffers(true) cimmand do nothing
#define ENABLE_DUAL_BUFFER true


// ==== DMD_RGB pins ====
// mux pins - A, B, C... all mux pins must be selected from same port!
#define DMD_PIN_A PB6
#define DMD_PIN_B PB5
#define DMD_PIN_C PB4
#define DMD_PIN_D PB3
#define DMD_PIN_E PB8
// put all mux pins at list
uint8_t mux_list[] = { DMD_PIN_A , DMD_PIN_B , DMD_PIN_C , DMD_PIN_D , DMD_PIN_E };

// pin OE must be one of PB0 PB1 PA6 PA7
#define DMD_PIN_nOE PB0
#define DMD_PIN_SCLK PB7

// Pins for R0, G0, B0, R1, G1, B1 channels and for clock.
// By default the library uses RGB color order.
// If you need to change this - reorder the R0, G0, B0, R1, G1, B1 pins.
// All this pins also must be selected from same port!
uint8_t custom_rgbpins[] = { PA6, PA0, PA1, PA2, PA3, PA4, PA5 }; // CLK, R0, G0, B0, R1, G1, B1

// Fire up the DMD object as dmd<MATRIX_TYPE, COLOR_DEPTH>
// We use 64x32 matrix with 16 scans and 4bit color:
DMD_RGB <RGB64x32plainS16, COLOR_4BITS_Packed> dmd(mux_list, DMD_PIN_nOE, DMD_PIN_SCLK, custom_rgbpins, DISPLAYS_ACROSS, DISPLAYS_DOWN, ENABLE_DUAL_BUFFER);
// other options are:
// <RGB32x16plainS8> -  32x16 matrix with 8scans
// <RGB80x40plainS20> - 80x40 matrix with 20scans
// <RGB64x64plainS32> - 64x64 matrix with 32scans
// Color depth - <COLOR_4BITS_Packed>, <COLOR_4BITS> or <COLOR_1BITS>


// --- Define fonts ----
// DMD.h old style font
DMD_Standard_Font Arial_F(Arial_14);

void setup(void)
{
  dmd.init();
  dmd.setBrightness(200);
  dmd.disableFastTextShift(true);

}

void loop(void)
{
  // create foreground colors
  uint16_t col[] = {
    dmd.Color888(255, 0, 0), // red
    dmd.Color888(0, 255, 0), // green
    dmd.Color888(0, 0, 255)  // blue

  };
  uint16_t bg = 0;  // background - black
  int col_cnt = 3;   // color count

  // text
  char m[30] = "Hello Arduino!";
  dmd.selectFont(&Arial_F);
  dmd.setTextColor(col[0], bg);

  // shift steps in pixels for running text (positive - shift right, negative - left)
  int8_t step[] = { 1, -1, -2, 2 };
  // running text shift interval
  uint16_t interval = 30;

  long prev_step = millis();
  uint8_t col_ptr = 0;
  uint8_t i = 0, b = 0;
  uint8_t test = 255;
  uint8_t test_cnt = 4;


  dmd.drawMarqueeX(m, -1 * (dmd.stringWidth(m)), 0);
  dmd.drawStringX(0, 0, "23", col[1]);
  dmd.swapBuffers(true);


  while (1) {
    if ((millis() - prev_step) > interval) {

      // scrolling text - update it BEFORE fixed text
      if (dmd.stepMarquee(step[i], 0) & 1) { // if text is reached screen bounds

        // restart marquee after reaching the screen bounds
        dmd.clearScreen(true);
        // set next text color
        col_ptr++;
        if (col_ptr >= col_cnt) col_ptr = 0;
        dmd.setTextColor(col[col_ptr], bg);
        // set new text speed
        i++;
        if (i > 3) i = 0;
        // draw new marquee
        if (step[i] < 0) dmd.drawMarqueeX(m, dmd.width() - 1, 0);
        else dmd.drawMarqueeX(m, -1 * dmd.stringWidth(m), 0);
      }

      // draw fixed text AFTER scroll update
      dmd.drawFilledBox(0, 0, 15, dmd.height() - 1, bg);
      dmd.drawStringX(0, 0, "23", col[1]);

      // output mem buffer to matrix
      dmd.swapBuffers(true);
      prev_step = millis();

    }
  }
}

[board707]

And video
https://youtu.be/DoOcfGb0PLw

[board707]

I see you have mentioned Roger Clarks's library need to download.

It is not the library, it is STM32 Arduino support package.
You should remove the STM32 support, installed in your IDE and follow this instructions:
https://github.com/rogerclarkmelbourne/Arduino_STM32/wiki/Installation

[agganitk]

yess thanks i relaized this.. now doing this..

[agganitk]

I did but when I compile dmd_monochrome.. i see belwo errors.
If I don't add Adafruit_GFX_Library then i see
:\Users\INTEL\Documents\Arduino\libraries\DMD_STM32-dev-V2/DMD_STM32a.h:45:26: fatal error: Adafruit_GFX.h: No such file or directory

#include "Adafruit_GFX.h"

                      ^

but if i add Adafruit_GFX_Library folder in library then other errors such as
#include <Adafruit_I2CDevice.h>

[board707]

Please use Adafruit_GFX libary version 1.7
https://github.com/adafruit/Adafruit-GFX-Library/releases/tag/1.7.0

[agganitk]

I done everything but yet display is not working.
I checked all pins using logic analyzer. I see PA15 pin is not toggling and is always High.
#define DMD_PIN_SCLK PA15

Rest all pins (A, B , OE and data) are toggling as expected.

I run dmd_monocrhome program with commenting the #define DMD_PARA line.

[agganitk]

yes!!

[board707]

My congratulation!
Do you have any questions about displaying both fixed and scrolling text?

[agganitk]

I am yet to implement that.. Will come back.. I m sure I will have questions.. ;)
But overall library is amazing.. I see lot lot of work is done to make it.

[agganitk]

it is workingg!!!

[board707]

Thank you for your feedback
I added this effect to the examples, see the dmd_rgb_dual_buf.ino example