Http request in interrupt esp8266 not working

Question

So i have this code that whenever i click a button a interrupt starts. In this interrupt i want to do a get request to a webserver.

The thing is seperate the code, the interrupt code works and without an interrupt the http request also works. But when i put this together it doesn't.

Does anybody have an idea why this doesn't work?

// Libraries 
#include <ESP8266HTTPClient.h>
#include<ESP8266WiFi.h>
char ssid[] = "";
char pass[] = "";
int ledpin = 5; // D1(gpio5)
int button = 4; //D2(gpio4)
int buttonState=0;
ICACHE_RAM_ATTR void ISR() {
 static unsigned long last_interrupt_time = 0;
 unsigned long interrupt_time = millis();
 if (interrupt_time - last_interrupt_time > 200)
 {
 Serial.println("Drukknop ingedruk");
 Serial.println("Sending message to server");
 if (WiFi.status()==WL_CONNECTED)
 {
 HTTPClient http;
 String url="<httpurl>";
 http.begin(url);
 http.addHeader("Content-Type","text/plain");
 int httpCode=http.GET();
 Serial.println(httpCode);
 String payload=http.getString();
 Serial.println("While sending I received this from server : "+payload);
 http.end();
 }
 else
 {
 Serial.println("Internet Problem!");
 } 
 }
 last_interrupt_time = interrupt_time; 
}
void setup() {
 Serial.begin(115200);
 WiFi.begin(ssid,pass);
 while(WiFi.status() !=WL_CONNECTED)
 {
 delay(500);
 Serial.println("Waiting for connection");
 }
 Serial.println("Connected...");
 delay(1000);
 if (WiFi.status() ==WL_CONNECTED)
 {
 Serial.println("Wi-Fi Connected!");
 }
 delay(5000);
 Serial.println("ok");
 pinMode(button, INPUT_PULLUP);
 attachInterrupt(digitalPinToInterrupt(button), ISR, RISING);
}
void loop() {
}

Answer 1

Doing something as complex as a HTTP request in an interrupt is a very very silly idea. Instead set a flag in the interrupt routine and examine that in the main loop() function to perform your HTTP request.

• Thomas Van Raemdonck: Thank you, this works
• romkey: @ThomasVanRaemdonck if it works (and it should) please accept Majenko's answer as correct; that helps other users see the correct answer and gives Majenko credit.