SPI not working in single colour p10 panel

[Ramkumar073]

I got an output while using parallel library but when it comes to spi library I didn't get anything in my p10 panel

[board707]

What the controller do you use? STM32 or RP2040?

[Ramkumar073]

I am using BluePill STM32, Got Output for Parallel but not for SPI , Here below the Code Correction

//----------------------------------------------- //#define DMD_PARA

// Pins I used for Both Parallel and SPI are Same connection

define DMD_PIN_A PB11

define DMD_PIN_B PB12

define DMD_PIN_nOE PB1

define DMD_PIN_SCLK PB10

[board707]

What pins do you use for CLK and DATA signal? Could you please show your code used for testing?

[Ramkumar073]

I am using SPI 1 so A5 as a CLK and A7 as a DATA Here below is my coding part (I am using SPI library so I comment like this //#define DMD_PARA)

//........................................................ /*-------------------------------------------------------------------------------------- Demo code for DMD panels

DMD_STM32a example code for STM32F103xxx board ------------------------------------------------------------------------------------- */ // choose between Parallel ans SPI wiring // comment line below for SPI connection //#define DMD_PARA

/-------------------------------------------------------------------------------------- Includes --------------------------------------------------------------------------------------/

if defined(DMD_PARA)

include "DMD_Monochrome_Parallel.h"

else

include "DMD_MonoChrome_SPI.h"

endif

// Fonts includes

include "st_fonts/UkrRusArial14.h"

pragma GCC diagnostic ignored "-Wnarrowing"

pragma GCC diagnostic ignored "-Woverflow"

include "gfx_fonts/GlametrixLight12pt7b.h"

include "gfx_fonts/GlametrixBold12pt7b.h"

pragma GCC diagnostic warning "-Wnarrowing"

pragma GCC diagnostic warning "-Woverflow"

//Number of panels in x and y axis

define DISPLAYS_ACROSS 2

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

// ----- Select pins for P10 matrix connection ------------ // pins A, B, SCLK may be any digital I/O, pin nOE should be Timer3 PWM pin as PB0,PB1 // if connect as SPI, do not use corresponding MiSO pin - PA6 for SPI1 and PB14 for SPI2

define DMD_PIN_A PB11

define DMD_PIN_B PB12

define DMD_PIN_nOE PB1

define DMD_PIN_SCLK PB10

// pins for SPI connect // SPI specific pins as CLK and R_DATA has predefined values: // for SPI(1) CLK = PA5 R_DATA = PA7 // for SPI(2) CLK = PB13 R_DATA = PB15 // --------------------------------------------------------

//=== Config for Parallel connect ====

if defined(DMD_PARA)

//pins for rows at x axis // example for two rows // all those pins must be selected from same port! uint8_t pins[] = { PA5, PA7, PA6 }; // CLK , row1, row 2

//Fire up the DMD object as dmd DMD_Monochrome_Parallel dmd(DMD_PIN_A, DMD_PIN_B, DMD_PIN_nOE, DMD_PIN_SCLK, pins, DISPLAYS_ACROSS, DISPLAYS_DOWN, ENABLE_DUAL_BUFFER);

else

//=== Config for SPI connect ==== SPIClass dmd_spi(1); DMD_MonoChrome_SPI dmd(DMD_PIN_A, DMD_PIN_B, DMD_PIN_nOE, DMD_PIN_SCLK, DISPLAYS_ACROSS, DISPLAYS_DOWN, dmd_spi, ENABLE_DUAL_BUFFER);

endif

// --- Define fonts ---- // DMD.h old style font DMD_Standard_Font UkrRusArial_F(UkrRusArial_14);

// GFX font with sepatate parts for Latin and Cyrillic chars DMD_GFX_Font GlametrixL((uint8_t)&GlametrixLight12pt7b,(uint8_t)&GlametrixLight12pt8b_rus,0x80,13);

/*-------------------------------------------------------------------------------------- UTF8 char recoding

--------------------------------------------------------------------------------------/ int utf8_rus(char dest, const unsigned char* src) {

uint16_t i, j; for ( i =0, j =0; src[i]; i++) { if ((src[i] == 0xD0 )&& src[i+1]) { dest[j++] = src[++i] - 0x10;} else if ((src[i] == 0xD1 )&& src[i+1]) {dest[j++] = src[++i] + 0x30; } else dest[j++] = src[i]; } dest[j] ='\0'; return j; }

/-------------------------------------------------------------------------------------- setup Called by the Arduino architecture before the main loop begins --------------------------------------------------------------------------------------/

void setup(void) {

// initialize DMD objects // scan DMD row each 700 us dmd.init(700); dmd.setBrightness(80);

}

/-------------------------------------------------------------------------------------- loop Arduino architecture main loop --------------------------------------------------------------------------------------/ void loop(void) {

// text
const char m[] = "HELLO WORLD!";
// transcode message to UTF for use with GFX fonts
char k[30];
utf8_rus(k, (const unsigned char* )m);

// but initially select standard font
dmd.selectFont(&UkrRusArial_F);

// 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 = 50;

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

 // Cycle for tests:
// -- running texts moving at x and y axis with single and double speed
// -- brightness control
// -- vertical scrolling message
while (1) {
    if ((millis() - prev_step) > interval) {
        if (test >= test_cnt) {
            test = 0;
            // draw message
            dmd.drawMarqueeX(m, -1 * (dmd.stringWidth(m)), 0);
            dmd.swapBuffers(true);

        }
        switch (test) {
          // moving text at x axis
        case 0:
            if (dmd.stepMarquee(step[i], 0) & 1) { // if text is reached screen bounds

                dmd.clearScreen(true);
                i++;
                // if all moving finished
                if (i > 3) {
                  // go to next stage
                    i =0;
                    test++;
                    dmd.drawMarqueeX(m, 0, 0);
                }
                else {
                    if (step[i] < 0) dmd.drawMarqueeX(m, dmd.width() - 1, 0);
                    else dmd.drawMarqueeX(m, -1 * dmd.stringWidth(m), 0);
                }
            }
            else {

                if (step[i] != 1) dmd.drawFilledBox(0, 0, 5, dmd.height() - 1, GRAPHICS_INVERSE);
            }
            // output mem buffer to matrix
            dmd.swapBuffers(true);
            break;

        // change brightness
        case 1:
            b++;
            dmd.setBrightness(b);
            if (b > 200) {
                test++;
                b = 80;
                i = 0;
                dmd.setBrightness(b);
                dmd.drawMarqueeX(m, 0, 0);
            }
            dmd.swapBuffers(true);
            break;

        // moving text at y axis
        case 2:
            if (dmd.stepMarquee(0, step[i]) & 1) {

                // clear the screen
                dmd.clearScreen(true);
                // select new moving speed
                i++;
                // if all moving finished
                if (i > 3) {
                  // go to next stage
                    test++;
                    // select GFX font for vertical scroll
                    dmd.selectFont(&GlametrixL);
                    dmd.drawMarquee(k, strlen(k), dmd.width() - 1, 0, 1);

                }
                else {
                    if (step[i] < 0) dmd.drawMarqueeX(m, 0, dmd.height());
                    else dmd.drawMarqueeX(m, 0, 0);
                }
            }
            // output mem buffer to matrix
            dmd.swapBuffers(true);
            break;

        // vertical scrolling    
        case 3:

            dmd.stepMarquee(-1, 0, 1);
            dmd.swapBuffers(true);
            break;

        }

        prev_step = millis();

    }
}

}

[board707]

Thank you. At first look I don't see any problems with code. What is the version of the library you use? What kind of STM32 bluepill board - is it F103C8 or C6 chip?

[Ramkumar073]

Actually above code was taken from your example dmd_monochrome I just modified below line only

define DISPLAYS_ACROSS 2 (from) #define DISPLAYS_ACROSS 1

because I have to use two panel

[Ramkumar073]

It is F103C8 Adafruit gfx 1.7 version and also tried to use 1.8 , 2 version

[board707]

I mean what is the version of the DMD_STM32 library. You can see actual version number in the library.properties file or at start of DMD_STM32a.h file

[Ramkumar073]

VERSION 0.9.3

[board707]

Sorry, I just discovered that I forgot to change the version number in DMD_STM32a.h file. Could you please to check the version in the library.properties file in the library folder in your Arduino libraries directory. Sorry for inconvenience.

[Ramkumar073]

Version 1.0.0

[board707]

Hi I have tested your code with your pins configuration - it works fine for me with v1.0.0 and v0.9.5.

The only change I made in your code - fixed dest parameter type in utf8_rus() function header. In your code it was:

int utf8_rus(char dest, const unsigned char* src)

Correct header should be:

int utf8_rus(char* dest, const unsigned char* src)

but I think that it was just a typo.

[Ramkumar073]

Yes, that's typo mistake but I checked with corrected code and with pin connection still I am not getting anything in my display and also, I checked in logical analyzer there was no pulse generation by DATA pin (PA5) could you please suggest any other reason for this problem.

[board707]

It seems to be a hardware problem. Please check that mcu on the board is STM32F103 and not a CS32 or CH32 clone. Check the soldering, especially PA7 and GND pins...

If you have another Bluepill board, try with it.

[Ramkumar073]

ok thanks and then I am using buffer IC 74hc245 between bluepill and p10 panel, is there any problem?

[board707]

Are you using it with both Parallel and SPI mode? If it works in Parallel - I don't see why it have not work with SPI....

[Ramkumar073]

yes, it works in parallel not in SPI. ok I will try with another bluepill.

[board707]

there was no pulse generation by DATA pin (PA5)

It can be just a typo again, but please note that in SPI mode DATA matrix pin should be connected to PA7, whereas CLK pin to the PA5 pin

[Ramkumar073]

sry that was my typo mistake but I am sure DATA pin is connected to A7 and CLK with A5