I use: "rtc_time_get() / rtc_clk_slow_freq_get_hz()" as second clock, which is accurate.
"gettimeofday(&tv, NULL)" is inaccurate

Hello All, I have found a problem which causes the deviation of the RTC clock. It seems be be in software somewhere. When I use the rtc_time_get() function the clock is accurate. When I use the gettimeofday() function the clock deviation is about 700ppm. The gettimeofday() is inaccurate both when I ...

Well the whole idea is to use an accurate 32khz crystal clock for the RTC. Normally these crystals are more accurate then the main clock. (I see that it actually is 10ppm, which is not bad...) Now I am testing without going to deep sleep, but later deep sleep is a must. So then we also need the 32kH...

Is there anybody who has implemented a 32kHz crystal clock at the ESP32-S3-WROOM-1U-N4R2?
If so, is your circuit accurate?
Can be please share your circuit with me? It would be very helpful...

Many thanks in advance!

The firmware does not goto sleep.
I reset the clock and 24hours later I check it.
In 24 hours the time drift is about a minute.
I retrieve the clock with the gettimeofday function.

Hi,

I checked if the external crystal is running normally at my application firmware and that is the case.
So the RTC does not run at the internal oscillators.
I checked it by short circuiting the crystal. Then I get a message in my debug output, the internal oscillator is taking over.

Hello All, I am using the ESP32-S3 (ESP32-S3-WROOM-1U-N4R2), and we need an accurate RTC. At the hardware I have connected a 32.378Hz crystal clock at pin 8 (IO15) and pin 9 (IO16). We use the ABS07-32.768KHZ-T crystal and have load capacitors of 15pF. The problem is that the clock is very inaccurat...