user48730: I'm trying to use a flow meter with Wemos Mini.
Most tutorials are using Arduino boards ( which code and HW work OK ), but since I want this device to send alerts over the internet when abnormal usage/leakage is detected, I want to use Wemos Mini using How to Use Water Flow Sensor - Arduino Tutorial. On top of if will add my code for notifications using Telegram.
BUT - after uploading the original code (before adding Telegram changes ), an error occurs during code run : ISR not in IRAM!
I tried to change Pin - but still getting this error,

user76576: This happens because of conflicts between Serial and external interrupts
Put ICACHE_RAM_ATTR before your interrupt function, like this  ICACHE_RAM_ATTR void ISR()

48730: <p>I'm trying to use a flow meter with Wemos Mini.
Most tutorials are using Arduino boards ( which code and HW work OK ), but since I want this device to send alerts over the internet when abnormal usage/leakage is detected, I want to use Wemos Mini using <a href="https://www.instructables.com/id/How-to-Use-Water-Flow-Sensor-Arduino-Tutorial/" rel="nofollow noreferrer">How to Use Water Flow Sensor - Arduino Tutorial</a>. On top of if will add my code for notifications using Telegram.</p>

<p>BUT - after uploading the original code (before adding Telegram changes ), an error occurs during code run : <code>ISR not in IRAM!</code></p>

<p>I tried to change Pin - but still getting this error,</p>
 76576: <p>This happens because of conflicts between Serial and external interrupts
Put ICACHE_RAM_ATTR before your interrupt function, like this <code> ICACHE_RAM_ATTR void ISR()</code></p>
