Add support for the EL133UF1 13.3" panel used on Inkplate 13SPECTRA

[JosipKuci]

Add support for the EL133UF1 Spectra 6 panel which is used on the Soldered Inkplate 13SPECTRA device, along with a define used to pre-configure pins for use with the Inkplate 13SPECTRA device.

References

• Inkplate 13SPECTRA device: https://soldered.com/products/inkplate-13spectra?_pos=1&_psq=13spectra&_ss=e&_v=1.0
• Inkplate 13SPECTRA Driver (Arduino Library): https://github.com/SolderedElectronics/Inkplate-Arduino-library/tree/master/src/boards/Inkplate13SPECTRA

Changes

• bb_epaper.h - Added enum EP133_SPECTRA_1200x1600 to display types, right before EP_PANEL_COUNT. Added enum EPD_INKPLATE13SPECTRA to products with built-in EPDs
• bb_ep.inl - Added epd133_spectra_init and epd133_spectra_init_slave sequences, one for each onboard IC, following the sequence available in the Inkplate Arduino Library, added panel details in the panelDefs array.
• bb_epaper.cpp - Added switch statement for automatically configuring the pins when EPD_INKPLATE13SPECTRA is selected
• arduino_io.inl - bbepWriteCmd had a milisecond delay before asserting CS, which caused a framebuffer misalignment on the second IC of the panel, show on the image below. This was fixed by either lowering it to 1 microsecond (as done currently) or by removing said delay.

Testing

Testing was done with the following Arduino sketch:

#include <bb_epaper.h>
#include "Fonts/Roboto_Black_24.h"
BBEPAPER bbep;

void setup(void)
{
int rc;

   Serial.begin(115200);
   delay(3000);
   Serial.println("Starting...");
   rc = bbep.begin(EPD_INKPLATE13SPECTRA);
   if (rc == BBEP_SUCCESS) {
      bbep.allocBuffer(); 

      // Draw 6 vertical color bands across the full 1600x1200 canvas
      const uint8_t colors[6] = {BBEP_BLACK, BBEP_WHITE, BBEP_YELLOW, BBEP_RED, BBEP_BLUE, BBEP_GREEN};
      int bandW = bbep.width() / 6; // ~266px each
      for (int i = 0; i < 6; i++) {
         int x = i * bandW;
         int w = (i == 5) ? (bbep.width() - x) : bandW;
         bbep.fillRect(x, 0, w, bbep.height(), colors[i]);
      }

      // White box behind the text so it's readable regardless of band color
      bbep.fillRect(0, 0, 420, 170, BBEP_WHITE);

      // Draw text in the top-left box
      bbep.setFont(Roboto_Black_24);
      bbep.setCursor(10, 40);
      bbep.setTextColor(BBEP_BLACK);
      bbep.println("bb_epaper");
      bbep.println("Inkplate 13 SPECTRA");
      bbep.println("Spectra 6 1600x1200");

      bbep.writePlane(); 
      bbep.refresh(REFRESH_FULL); 
      bbep.wait();
      bbep.sleep(LIGHT_SLEEP);
   } else {
      Serial.println("Panel init failed");
   }
} 

void loop(void)
{
} 

Which produced the following expected output: