RealTimeClock inaccurate

[realolman]

I got a Uno R4 wifi hoping to use it as a wireless datalogger... tracking the state of the digital inputs with a timestamp.
It appears to me that the RTC is so inaccurate that it is not going to be useful
I just read the topic "Can we fix the RTC?" there didn't seem to be a fix at that point.
Has there been any fixes since that thread?

I would be interested in connecting some sort of RTC on a chip to the R4, but I haven't been able to find anything that specifically shows how to do that... I really am not interested in any programming to try to make up for the clock's accuracy.
thank you
Realolman

[UKHeliBob]

Can you connect your data logger to the Internet ?

[jremington]

The DS3231 modules typically keep time accurate to around +/- 1 minute per year.

[Grumpy_Mike]

@realolman

Can we fix the RTC?" there didn't seem to be a fix at that point.
Has there been any fixes since that thread?

No.
This is because the Uno R4 has a free running clock so you can't fix it as it stands.

However, you can get other boards based on the same processor that has crystals fitted to get round this problem.

See.

Waveform synthesis on the R4

Note that the EK-RA4M1 devboard has a Segger debug chip on it as well, so it is easy to pop on the Arduino Minima bootloader and run code on the board from the Arduino IDE. This then gives one the full debug capability of using a Segger device, the main difference is that under e2studio the registers are fully named, whereas running the Segger Jlink software separately the registers are generic. https://www.renesas.com/en/products/microcontrollers-microprocessors/ra-cortex-m-mcus/ek-ra4m1-eval…

[gpb01]

@Grumpy_Mike

However, you can get other boards based on the same processor that has crystals fitted to get round this problem.

I used THIS one ... it has both the quartz for the main MCU clock and the quartz for the RTC at a very affordable cost. I loaded the Arduino UNO R4 MINIMA bootloader onto it and, with just a few instructions, activated the two clocks with their respective crystals.

It is also quite easy to write a 'variant' to use all the pins it provides.

Guglielmo

[realolman]

I'm disappointed to see that there is no fix... It's not like I spent much money on it, but not being able to keep reasonably accurate time on a microprocessor is not something I saw coming... I could get NTP time I guess, but I didn't want to.

I bought it strictly for the wifi. I'd a traded the LED matrix for RTC.

Thank you all for your posts
Realolman

[gpb01]

@realolman:

If you search here on the forum, this topic has been discussed many times and some solutions have been proposed to improve the accuracy.

Try reading HERE.

Guglielmo

[realolman]

Thank you for your reply
I read this before i posted.

Realolman

[gpb01]

@realolman

I read this before i posted.

Unfortunately, there are no other solutions without quartz ...

Guglielmo