esp8266 interrupts

[soosp]

On esp8266 platform interrupt callback functions must be in IRAM (See: https://arduino-esp8266.readthedocs.io/en/latest/reference.html#interrupts):

void IRAM_ATTR D7SClass::isr1() {
  D7S.int1();
}

instead of the simple

void D7SClass::isr1() {
  D7S.int1();
}