mklemarczyk
commented
2 years ago Hello I made simple test, even without using BLE and WiFi the time shifts very much. How I can use it as alarm to wake me up in the morning if the time is so irrelevant after longer period of time ?
I expect that time will fluctuate but the difference in real time (my PC) and RTC time (Arduino NANO 33 IoT) will stay stable (not exceeding +/- 1 second).
For the experiment the Arduino was connected to the PC and no other I/Os were used. The time difference grown in 30 min to 15 seconds (0.8 % degradation).
Real time -> RTC date RTC time millis micros
13:10:48.899 -> 24/06/22 16:00:03 3202 3202622
13:24:24.677 -> 24/06/22 16:13:46 819009 819010002
13:31:57.135 -> 24/06/22 16:21:22 1271482 1271482659
13:35:42.867 -> 24/06/22 16:25:10 1497168 1497168861
13:39:35.746 -> 24/06/22 16:29:05 1730078 1730079079/*
Simple RTC for Arduino Zero and MKR1000
Demonstrates the use of the RTC library for the Arduino Zero and MKR1000
This example code is in the public domain
http://arduino.cc/en/Tutorial/SimpleRTC
created by Arturo Guadalupi <a.guadalupi@arduino.cc>
15 Jun 2015
modified
18 Feb 2016
modified by Andrea Richetta <a.richetta@arduino.cc>
24 Aug 2016
*/
#include <RTCZero.h>
/* Create an rtc object */
RTCZero rtc;
/* Change these values to set the current initial time */
const byte seconds = 0;
const byte minutes = 0;
const byte hours = 16;
/* Change these values to set the current initial date */
const byte day = 24;
const byte month = 6;
const byte year = 22;
void setup()
{
Serial.begin(9600);
rtc.begin(); // initialize RTC
// Set the time
rtc.setHours(hours);
rtc.setMinutes(minutes);
rtc.setSeconds(seconds);
// Set the date
rtc.setDay(day);
rtc.setMonth(month);
rtc.setYear(year);
// you can use also
//rtc.setTime(hours, minutes, seconds);
//rtc.setDate(day, month, year);
}
void loop()
{
// Print date...
print2digits(rtc.getDay());
Serial.print("/");
print2digits(rtc.getMonth());
Serial.print("/");
print2digits(rtc.getYear());
Serial.print(" ");
// ...and time
print2digits(rtc.getHours());
Serial.print(":");
print2digits(rtc.getMinutes());
Serial.print(":");
print2digits(rtc.getSeconds());
// ... and ticks
Serial.print(" ");
Serial.print(millis());
Serial.print(" ");
Serial.print(micros());
Serial.println();
delay(1000);
}
void print2digits(int number) {
if (number < 10) {
Serial.print("0"); // print a 0 before if the number is < than 10
}
Serial.print(number);
}Used versions:
- Windows: 10 (19044.1766)
- Arduino IDE: 2.0.0-rc8
- Arduino SAMD Boards (32-bits ARM Cortex-M0+): 1.8.13
- RTCZero: 1.6.0
Hello, I have very particular issue when using the RTCZero with my Arduino NANO 33 IoT. I am working with WiFi, BT and time at the same time to control light strength in setup of LED and movement sensor.
I found your library to exploit the internal RTC clock. I set it from NTP server using WiFi. After that I shut down the WiFi and move to BT to expose the values for diagnostic.
After many tries without your library, my time was decaying and getting more and more late. With your library I have totally opposite experience. The time still desynchronize, in that case into the future. At beginning the minutes, hours, days in the future from real time.
Do you have any idea what can cause such behavior? I set time once, and after I read it only.