Platformio setup

[kocinski15]

I found out your library in platformio registry here: https://registry.platformio.org/libraries/board707/DMD_STM32
However I can not find way to force Platformio using deprecated Arduino core that is compatible.
Is there an esy way to compile DMD_STM32 in Platformio.
How is the progress of porting library to Stm32duino that was mentioned in of the postings.?

[board707]

Is there an eфsy way to compile DMD_STM32 in Platformio.

As alternative you can use the library with RP2040 boards.

How is the progress of porting library to Stm32duino that was mentioned in of the postings.?

Unfortunately, this turned out to be more difficult than I thought. Support for Stm32duino Core is not expected in the upcoming releases.

[kocinski15]

I am working with PWM panel based on FM6373. Is library supporting RP2040 for PWM chipsets?

By the way I compiled working example with arduino IDE for STM32F401. I noticed that only compiling with -O1 optimization gives correct picture. Other optimizations result in distortion.
While -O1 you can even overclock STM32F401 to 112Mhz and it still gives correct signal.
There may be some optimization-sensitive timings in sending loop waveforms that cause it.

[board707]

Is library supporting RP2040 for PWM chipsets?

Not in the moment, but I am working on it.

I noticed that only compiling with -O1 optimization gives correct picture. Other optimizations result in distortion.
There may be some optimization-sensitive timings in sending loop waveforms that cause it.

very interesting, thanks for the information!

[kocinski15]

Further testing of the same code for FM6373 on STM401 show that eventhogh dual buffer is false
#define ENABLE_DUAL_BUFFER false

Program still requires swapBuffers() to be called , otherwise nothing gets tansferred to the matrix.
I am having some trouble with set_brightness() to as well as colorspace which seems to be limited to 1 bit even when declared as 4 bits. Do you confirm those limitations in implementation for FM6373?

[board707]

Hi

eventhogh dual buffer is false #define ENABLE_DUAL_BUFFER false
Program still requires swapBuffers() to be called , otherwise nothing gets tansferred to the matrix.

Indeed, when working with such panels you should use swapBuffers()...
SPWM drivers has on-board SRAM, so when outputting to the panel, it behaves as if using a double buffer. Therefore, the same method swapBuffers() is used to output data from the sketch, just like with a double buffer.

I am having some trouble with set_brightness()

Sorry, the set_brightness() method is not implemented on SPWM code.

I apologize, all these questions should have been answered in the manual, but the documentation for the PWM mode is still in process.

colorspace which seems to be limited to 1 bit even when declared as 4 bits.

Please clarify how you discovered this. This is unexpected to me, since PWM drivers should support 4-bit color. At least, there are no restrictions on this in the code.

[board707]

Is library supporting RP2040 for PWM chipsets?

I just released a new update, that include RP2040 support for SPWM chipsets.
See v1.2.5

[kocinski15]

colorspace which seems to be limited to 1 bit even when declared as 4 bits.

Please clarify how you discovered this. This is unexpected to me, since PWM drivers should support 4-bit color. At least, there are no restrictions on this in the code.

DMD_RGB_FM6373 <4,64,32,16,0, COLOR_4BITS> dmd(mux_list, DMD_PIN_nOE, DMD_PIN_SCLK, custom_rgbpins, DISPLAYS_ACROSS, DISPLAYS_DOWN, ENABLE_DUAL_BUFFER);
/*
..
*/
for (int speed=0;speed<10;speed++){
// fill the matrix with points row by row
for (int i = 0; i < dmd.height(); i++) { // h=32
for (int j = 0; j < dmd.width(); j++) { // w=64
fg = dmd.Color888(j * 4, j * 4, i * 8);
dmd.drawPixel(j,i, fg);
//delay(1);
}
dmd.swapBuffers(true);
}

Tried to show kind of a rainbow with the above code but the output is realy only 4 unifomly colored rectangles.

[board707]

the output is realy only 4 unifomly colored rectangles.

Thanks for the feedback. I will test it.

[kocinski15]

Is library supporting RP2040 for PWM chipsets?

I just released a new update, that include RP2040 support for SPWM chipsets. See v1.2.5

Great news. Will it automatically support RP2350? version -2 variant of Rpi Pico?

[board707]

Will it automatically support RP2350?

I haven't tested it

[kocinski15]

I have tested FM6373 with RP2040 and demo is working with the same color space limitations as in STM32F40x. I will give a try on RP2350 in coming days too.

[kocinski15]

I have tested FM6373 with RP2350 and demo is working with the same color space limitations as in STM32F40x.
Occasional flicker happens once every minute or so, you can see a picture offset vertically by one line for one frame or so.
Do not use flag :
build_flags =
-DPIO_FRAMEWORK_ARDUINO_ENABLE_FREERTOS
it causes picture flickering

I would be glad to see color space corrected for FM6373. It sould be fairly easy, maybe it is just a bug in transcoding values from framebuffer to pwm data registers? Going further with transcoding: with SPWM drivers implementing gamma correction should also be easier than with simple latch registers.

[kocinski15]

Actual chip symbol id FM6373C - could -C suffix be a reason of color space limitations?

[board707]

could -C suffix be a reason of color space limitations?

I don't think so

[kocinski15]

My concern raised two different releases of the config for NovaLCT, separate for each chip. FM6373 support added in 2024 and FM6373C in 2025.