Periodic or interrupt wakeup

#include <ESP8266WiFi.h>
#define USERBUTTON 12 // GPIO012 on ESP or D6 on WeMos

void setup() {
  Serial.begin(115200);
  Serial.setTimeout(2000);
  int userButtonValue = digitalRead(USERBUTTON);

  while(!Serial) { }

  Serial.println("Wake up!");
  
  Serial.print("User button value: ");
  Serial.println(userButtonValue);

  if (userButtonValue == 0) {
    Serial.print("User long pressed button: ");
  }

  Serial.println("Do task");
  Serial.println("Going into deep sleep for 10s, unless button pressed...");
  ESP.deepSleep(10e6);
}

void loop() {
}

BOARD?=esp8266com:esp8266:d1_mini
PORT?=/dev/cu.wchusbserial1410
BUILD=build
# Arduino CLI version 0.14.0 is used.

.PHONY: default lint all flash clean

default: lint all flash clean

lint:
	cpplint --extensions=ino --filter=-legal/copyright *.ino

all:
	arduino-cli compile --fqbn $(BOARD) --output-dir $(BUILD) ./

flash:
	arduino-cli upload --fqbn $(BOARD) --port $(PORT) --input-dir $(BUILD)

clean:
	rm -r build