RTC and Data Logger for WiFi Rev 2?

I'm still new to the Arduino world. I'm working on a garage door position monitor using a cheap Chinese incremental optical rotary encoder, a couple of non-blocking state machines for the door state and the encoder, and Blynk. Things are working rather well on the bench so far.

I'd like to have a Real Time Clock and a Data Logger. Unfortunately, the Adafruit Data Logging Shield (1141) does not work with the ATMEGA4809 MCU and Adafruit tells me they have no plans to make it compatible.

  • Are there any other alternatives to the Adafruit data logger / RTC for the Uno WiFi Rev 2?
  • Should I change to a different platform (e.g., a regular Uno) and use a WiFi shield with a Data Logger shield?
  • Should I just upload data to Blynk servers and forget about local storage? I would still need a good RTC, though.

The Adafruit Data Logger shield does appear to work with the WiFi Rev 2 but you have to reconfigure the Chip Select for the SD card.

Cut the SD card Chip Select (CS) link on the back and strap it to another digital output. The board has been designed to facilitate this. I used pin 4 so it's compatible with the Ethernet 2 shield. Mine is now working a treat.

The problem with the Adafruit configuration of using Pin 10 for CS appears to be that, for some reason I have yet to identify, when you try to access the SD card, the pin pulses low for around seven microseconds then that's it. If you scope the CS line when it's connected to pin 4 it toggles away for the duration of the transaction as you may expect.

If anyone out there knows why this is I'd love to know.