Real time clock seems slow

[CarlKCarlK]

Greetings. It's working great and is even now useable. Here are some minor issues that I notice:

It gets its time from the real-time clock that tells how long the device has been running. That seems to be about 5 seconds per minute slow.

Thanks for your work on this project.

[matgla]

Hi,
What timer for a real-time clock is in use?
If RTC, then it is not implemented yet.

How do you measure time? If you compare it to host time, it is expected anyway. Those simulations are not real-time, so virtual time should be used.

[CarlKCarlK]

I understand. Thanks.

[matgla]

This is to be checked. If other timer than RTC is in use and simulation accuracy is set to enough precision, then virtual time should be reported correctly.

[CarlKCarlK]

I'm using https://docs.rs/embassy-time/latest/embassy_time/struct.Instant.html which apparently does NOT use the RTC.
It gives me milliseconds since power on. On real hardware, I see no noticeable drift even after a few days, but it is still not the RTC.

[matgla]

Hi, maybe you have a log or firmware with visible RTC slowness. It will be easier to debug :)

[CarlKCarlK]

I think this is unfixable because the simulation is not 1:1 time. So, feel free to close it as "won't fix".

p.s. If you want, I can give you the latest *.bin for my clock app with instructions how to set and display seconds and you can watch it drift. The emulation runs about 1/2 the speed of real time.