Time accuracy of Nano 33 IOT

[Hasenradball]

Hi,

I want to know whats behind the function:

WiFi.gettime();

I have the following Questions:
1.) what is the timeserver used for this functionality
2.) can the time server changed?
3.) is the time queried from an RTC?

Because the 33IOT has also an internal RTC which can be used as:

RTCZero rtc;
int _seconds{rtc.getSeconds()};
int _minute{rtc.getMinutes()};
int _hour{rtc.getHours()};
dprintf("%14s%02d:%02d:%02d\n", "RTC-time: ", _hour, _minute, _seconds);
sprintf(buffer, "%02d:%02d:%02d (RTC)", _hour, _minute, _seconds);

As I could recognized the time accuracy of the RTC is worse compared the functionality of WiFi.getTime().
Does anyone have more information to this topic?

[Klaus_K]

hasenradball:
1.) what is the timeserver used for this functionality

You could use Wireshark to monitor the traffic from the module and find out.

hasenradball:
As I could recognized the time accuracy of the RTC is worse compared the functionality of WiFi.getTime().
Does anyone have more information to this topic?

There is a version with an accurate RTC. It is called MKR Wifi 1010. The Arduino Nano 33 IoT is a cost optimized version and does not have a 32kHz clock crystal on the PCB. Have a look at the schematics in the store under DOCUMENTATION.

Arduino MKR WiFi 1010

[Hasenradball]

Klaus_K:
You could use Wireshark to monitor the traffic from the module and find out.
There is a version with an accurate RTC. It is called MKR Wifi 1010. The Arduino Nano 33 IoT is a cost optimized version and does not have a 32kHz clock crystal on the PCB. Have a look at the schematics in the store under DOCUMENTATION.

Arduino MKR WiFi 1010 — Arduino Official Store

Hi,
ok that a new information to me, so the Nano 33 IOT has no accurate RTC, and the MKR Wifi 1010 has an accurate RTC available, right?

[Hasenradball]

Hi,
do you know something about the WiFi.getTime()?

Timeserver, ...

[Klaus_K]

hasenradball:
do you know something about the WiFi.getTime()?

I have done a little experiment with Wireshark and Arduino Nano 33 IoT. I can see the following sequence:

• DNS request for 0.pool.ntp.org
• DNS response with 4 IP addresses all owed by different companies (data center and network stuff)
• NTP Version 4, client request to the first IP address received before
• NTP Version 4, server response back

If you want to try this yourself:

https://www.wireshark.org/