Get pin levels at time of interrupt, rather than the time of calling the handler

current implementation can cause false readings if previous handlers
take more time than the pin holds the level

Author: Me No Dev

cores/esp8266/core_esp8266_wiring_digital.c

@@ -111,6 +111,7 @@ static uint32_t interrupt_reg = 0;
 
 void interrupt_handler(void *arg) {
   uint32_t status = GPIE;
+  uint32_t levels = GPI;
   GPIEC = status;//clear them interrupts
   if(status == 0 || interrupt_reg == 0) return;
   ETS_GPIO_INTR_DISABLE();
@@ -122,7 +123,7 @@ void interrupt_handler(void *arg) {
     interrupt_handler_t *handler = &interrupt_handlers[i];
     if (handler->fn && 
         (handler->mode == CHANGE || 
-         (handler->mode & 1) == digitalRead(i))) {
+         (handler->mode & 1) == !!(levels & (1 << i)))) {
       // to make ISR compatible to Arduino AVR model where interrupts are disabled
       // we disable them before we call the client ISR
       uint32_t savedPS = xt_rsil(15); // stop other interrupts