Countdown with Timer1

Projects Programming
1

Goodmorning,
I want to make a countdown timer with timer1, but I am inexperienced with the library.
I have done one program but It doesn't work:

#include "TimerOne.h"

volatile int STbutton = 22;
int CDtimer = 0;
int Tcount = 10;


void setup(){
  Timer1.initialize(1000000);
  Timer1.attachInterrupt(clock);
  pinMode (STbutton, INPUT);
  Serial.begin(9600);
  
}

void clock(){
  if ( digitalRead(STbutton) == HIGH ){
    CDtimer = Tcount - 1;
  }
}
  
  
void loop(){
  if ( CDtimer >= 0 ){
      Serial.print(CDtimer);
      Serial.println(" sec");
  }
}

The program that i want to do It's simple:
Whenever STbutton == HIGH a timer start counting down every 1sec
Please any suggestions on the program or any help with the library.

2

Don't do serial prints in an ISR?

3

Thanks for the advice and the link but It doesn't fix the problem.

4

No need for that Library. Just use millis() to manage the timing. See the Blink Without Delay example sketch.

...R

5

Robin2:
No need for that Library. Just use millis() to manage the timing. See the Blink Without Delay example sketch.

...R

Thank you, this helped me a lot