multiple "stopwatch"

hello everybody :slight_smile: Im new in arduino world and before I write my question excuse me for my english.

I want to make 10 buttons to be inputs on arduino_one, every button is start and stop for its own
“stopwatch” and that arduino_one sends that time over rf 433 to arduino_two.
Arduino_two then receives that 10 times and compare its to threshold of 90sec if any time is biger then threshold then arduino_two print that time to LCD and print “lap time” to pc over serial and next to that time lap actual time meaning date and time.
As now:
I have no idea how to get “timestamp”
have only one “stopwatch”
On serial i get time every second not the “lap time” start-stop time.

I have figured out lcd print of the time and if time is biger then threshold serial output is displayed.
I found a way to recognize 10 times over rf433 by changing bitlenght // if (mySwitch.available()) {

if (( mySwitch.getReceivedBitlength()) == 32 ){""

code of sending arduino_one

#include <RCSwitch.h>
RCSwitch mySwitch = RCSwitch();

const int buttonPin = 9;    // the number of the pushbutton pin
const int ledPin = 13;      // the number of the LED pin
const int ledica = 11;

int ledState = HIGH;         // the current state of the output pin
int buttonState;             // the current reading from the input pin
int lastButtonState = LOW;// the previous reading from the input pin

unsigned long vrijeme = 0;
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50;    // the debounce time; increase if the output flickers

void setup() {
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);
   pinMode(ledica, OUTPUT);
  // set initial LED state
  digitalWrite(ledPin, ledState);

void loop() {
  // read the state of the switch into a local variable:
  int reading = digitalRead(buttonPin);

  // check to see if you just pressed the button 
  // (i.e. the input went from LOW to HIGH),  and you've waited 
  // long enough since the last press to ignore any noise:  

  // If the switch changed, due to noise or pressing:
  if (reading != lastButtonState) {
    // reset the debouncing timer
    lastDebounceTime = millis();
  if ((millis() - lastDebounceTime) > debounceDelay) {
    // whatever the reading is at, it's been there for longer
    // than the debounce delay, so take it as the actual current state:

    // if the button state has changed:
    if (reading != buttonState) {
      buttonState = reading;

      // only toggle the LED if the new button state is HIGH
      if (buttonState == HIGH) {
        ledState = !ledState;
  // set the LED:
  digitalWrite(ledPin, ledState);

  // save the reading.  Next time through the loop,
  // it'll be the lastButtonState:
  vrijeme = (millis() - lastDebounceTime);
  lastButtonState = reading;

void vrijeme_loop(void)
    (mySwitch.send((vrijeme/1000) ,32));
  void seriski_ispis(void)
     if (vrijeme/1000 > 10)
       digitalWrite(ledica, HIGH);
         digitalWrite(ledica, LOW);

code of reciver arduino_two

  Simple example for receiving

#include <RCSwitch.h>
#include <LiquidCrystal.h>

RCSwitch mySwitch = RCSwitch();
LiquidCrystal lcd(7, 6, 5, 4, 3, 8);

unsigned long time=0;
const int led = 13;

void setup() {
  mySwitch.enableReceive(0);  // Receiver on inerrupt 0 => that is pin #2
  lcd.begin(16, 2);
  pinMode(13, OUTPUT);

void loop()


 void read_data(void) 
    if (mySwitch.available()) {
 if (( mySwitch.getReceivedBitlength()) == 32 ){
 unsigned long  time1 = mySwitch.getReceivedValue();
  time = time1;

if (time > 90){
  digitalWrite(led, HIGH);
    Serial.print("1600/2: ");
    digitalWrite(led, LOW);

void lcd_display()
  lcd.setCursor(0, 0);
lcd.setCursor(0, 1);
  lcd.print("time pased");



I have no idea how to get "timestamp"

The Arduino doesn't have a clock. It has a stopwatch that starts when the Arduino boots up, and can't be stopped. You can still use that to get intervals. If you need exact times, you need a clock.

cant it get over serial via the pc?

cant it get over serial via the pc?


any advice,example ?

any advice,example ?

The Time library comes with Processing code and the needed Arduino code.

Try my stopwatch class - -