Development v12

Warning - Product Update

All the resources present on this section belong to Waspmote v12, Waspmote Plug & Sense! v12 and Meshlium v3.8.

If you have a Waspmote v15, Waspmote Plug & Sense! v15 or Meshlium v4.0 please go to the new Development Section.

Check what is your version and what are the differences between the old and the new one in this document.

» UT 08: millis function

This example shows how to use the millis() function to perform time-controlled loops

Required Materials

1 x Waspmote
1 x MiniUSB wire
1 x Battery

Notes

This example can be executed in Waspmote v12 and Waspmote v15

Code

/*
 *  ------   [UT_08] - millis() function   -------- 
 *
 *  Explanation: This example shows how to use the millis() function
 *  to perform time-controlled loops
 *
 *  Copyright (C) 2016 Libelium Comunicaciones Distribuidas S.L. 
 *  http://www.libelium.com 
 *  
 *  This program is free software: you can redistribute it and/or modify 
 *  it under the terms of the GNU General Public License as published by 
 *  the Free Software Foundation, either version 3 of the License, or 
 *  (at your option) any later version. 
 *  
 *  This program is distributed in the hope that it will be useful, 
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of 
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 *  GNU General Public License for more details. 
 *  
 *  You should have received a copy of the GNU General Public License 
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>. 
 *  
 *  Version:           3.0
 *  Design:            David Gascon 
 *  Implementation:    Yuri Carmona
 */

// define variable to store number of milliseconds
unsigned long previous;

// define timeout: 10 seconds
unsigned long TIMEOUT = 10000; // ms units


void setup() 
{ 
  USB.ON();
  USB.println(F("UT_08 example - millis function\n"));

  // get millis() value
  previous = millis();

  USB.print(F("millis() function returns the execution time (ms units):"));
  USB.println(previous);
  USB.println();
}



void loop() 
{
  // 1. get actual time
  previous = millis();
  
  USB.print(F("1. Enter while loop with previous = "));
  USB.println(previous);


  // 2. enter while loop for specified TIMEOUT
  while( (millis() - previous) < TIMEOUT )
  {
    // Do whatever...
    USB.print(F("2. Inside while loop until timeout. millis() = "));
    USB.println(millis());
    delay(1000);

    // Check overflow (mandatory sentence)
    if( millis()<previous )  previous = millis();
  }


  // 3. exit while loop
  USB.println(F("3. Exit while loop"));
  USB.println();
  
  
  delay(5000);
}







Output

H#
UT_08 example - millis function

millis() function returns the execution time (ms units):253

1. Enter while loop with previous = 470
2. Inside while loop until timeout. millis() = 766
2. Inside while loop until timeout. millis() = 1943
2. Inside while loop until timeout. millis() = 3120
2. Inside while loop until timeout. millis() = 4296
2. Inside while loop until timeout. millis() = 5473
2. Inside while loop until timeout. millis() = 6650
2. Inside while loop until timeout. millis() = 7826
2. Inside while loop until timeout. millis() = 9003
2. Inside while loop until timeout. millis() = 10180
3. Exit while loop

1. Enter while loop with previous = 16280
2. Inside while loop until timeout. millis() = 16576
2. Inside while loop until timeout. millis() = 17753
2. Inside while loop until timeout. millis() = 18930
2. Inside while loop until timeout. millis() = 20106
2. Inside while loop until timeout. millis() = 21283
2. Inside while loop until timeout. millis() = 22460
2. Inside while loop until timeout. millis() = 23636
2. Inside while loop until timeout. millis() = 24813
2. Inside while loop until timeout. millis() = 25990
3. Exit while loop

1. Enter while loop with previous = 32090
2. Inside while loop until timeout. millis() = 32386
2. Inside while loop until timeout. millis() = 33563
2. Inside while loop until timeout. millis() = 34740
2. Inside while loop until timeout. millis() = 35916
2. Inside while loop until timeout. millis() = 37093
2. Inside while loop until timeout. millis() = 38270
2. Inside while loop until timeout. millis() = 39446
2. Inside while loop until timeout. millis() = 40623
2. Inside while loop until timeout. millis() = 41800
3. Exit while loop

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