Error ISR not in IRAM!

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There are two ways to handle the ISR not in IRAM issue. These examples assume that your interrupt handling function is called MyInterruptHandler

You can simply add a pre-declaration of the ISR handler routine with ICACHE_RAM_ATTR before the interrupt handler name, like this:

void ICACHE_RAM_ATTR MyInterruptHandler();

This pre-declaration of the ISR handler should be near the top of your code, before void setup - where you initialise your interrupt like this:

attachInterrupt(digitalPinToInterrupt(5),MyInterruptHandler,FALLING);

your interrupt handler would then look like this:

 void MyInterruptHandler()
{
  // do your interrupt handling stuff in here....
}

Alternatively, you can skip the pre-declaration and do it in the ISR handler like this:

 void ICACHE_RAM_ATTR MyInterruptHandler()
{
  // do your interrupt handling stuff in here....
}

When you take this approach, your ISR handler MUST appear before your void loop in the sketch, otherwise you’ll get a “not declared in this scope” error when you compile the code (at least when using the Arduino IDE).

Pete.

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