lcdgfx

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Describe the bug DisplaySH1106_128x64_I2C::begin() crashes when external interrupts are enabled.

To Reproduce Steps to reproduce the behavior:

1. Create arduino sketch with following code

#include <HardwareSerial.h>
#include "lcdgfx.h"
#include "lcdgfx_gui.h"

constexpr float fVFac = 5.0f * ((220.0f + 33.0f) / 33.0f) * (1.0f / 1023.0f);

DisplaySH1106_128x64_I2C d = DisplaySH1106_128x64_I2C(-1);
volatile bool bPressed = false;
volatile uint16_t nDelayCnt = 0;

void setup() {

  Serial.begin(115200);
  Serial.println("*");

  PCICR |= (1 << PCIE1);
  // If these lines are uncommented, the program will die at the marked spot below and be stuck in a reboot loop
  //PCMSK1 = (1 << PCINT13);
  //EICRA |= (0 << ISC11) | (1 << ISC10); 
  
  Serial.println("begin...");
  delay(250);
  
  // This is the call that crashes 
  d.begin(); // Address 0x3C default
  
  Serial.println("set font...");
  delay(250);
  d.setFixedFont(ssd1306xled_font6x8);
  Serial.println("fill...");
  delay(250);
  d.fill( 0x00 );
  Serial.println("setup done!");
  delay(250);
}

void loop()
{
  float fAR = analogRead(A2);
  float fV = fVFac * fAR;
  uint8_t w = (100.0f / 18.0f) * fV;
  uint8_t v = floor(fV);
  uint8_t mv = 10 * (fV - v);
  char szText[5];
  sprintf(szText, "%2u.%1.1u V", v, mv);
  Serial.println("VCC: ");Serial.println(fV);
  Serial.println("set color...");
  delay(250);
  const char* p = szText;
  d.setColor(0);
  Serial.println("fill...");
  delay(250);
  d.fillRect(0, 0, 128, 64);
  Serial.println("set color...");
  delay(250);
  d.setColor(1);
  Serial.println("draw text...");
  delay(250);
  d.printFixed(0, 0, szText, STYLE_NORMAL);
  delay(1);
  if (nDelayCnt > 0) nDelayCnt--;
}

ISR(PCINT19_vect)
{
  Serial.print("X");
  if (nDelayCnt == 0)
  {
    bPressed = true;
    nDelayCnt = 200;
  }
}

3. Uncommenting the two lines will cause a crash but otherwise the program works fine

Expected behavior As it appears to me, enabling the external interrupts causes the reboot loop. I need those to interface with buttons, and would like not to need polling. So hopefully there is a workaround that allows both to run at the same time.

Screenshots If applicable, add screenshots to help explain your problem.

Please complete the following information:

• lcdgfx 1.1.4
• SHT1106
• Windows
• Arduino UNO
• Arduino IDE

Additional context Switching lcdgfx init and the register change did not help

Hi The library uses standard Wire library for Arduino environment. So it has nothing specific related to the crash.