RealTimeClock inaccurate

[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…