Suggestion for SD card reader/write and RTC

heikkij · January 8, 2020, 3:51pm

Any suggestions to use for RTC and SD cards ?
I have previously used the below (when using adafruit featherwing arduinos) but since the pinout is different for the wifi lora 32 (V2) you can’t stack them (also have not yet tried importing the libraries and if they even work).

So any suggestions of what to use ? I would need both battery backed up RTC and a lot of data to be saved when device is not capable of sending.

Supporter · January 9, 2020, 2:20pm

Here is an example for SD card:

heikkij · January 9, 2020, 4:17pm

Thanks! That worked on the SD above!

Update: changing gpio22 to gpio2 (to allow SDA&SCL to be used) also worked.
(when not the SDA&SCL pins are connected)

However, when I wire SDA and SCL the SD reader fails, and the I2C scanner also fails:

gist.github.com

https://gist.github.com/tfeldmann/5411375

i2c_scanner.ino

// --------------------------------------
// i2c_scanner
//
// Version 1
//    This program (or code that looks like it)
//    can be found in many places.
//    For example on the Arduino.cc forum.
//    The original author is not known.
// Version 2, Juni 2012, Using Arduino 1.0.1
//     Adapted to be as simple as possible by Arduino.cc user Krodal

This file has been truncated. show original

So what are the default pins/gpio for using I2C ?
(I also tried the OLED_SCL & OLED_SDA but that didn’t work either)

heikkij · January 10, 2020, 6:27am

Never mind, found the ESP32/I2C_Scanner/I2C_Scanner.ino example
(oddly enough the File->Examples you have in the Arduino IDE is different from the github, I thought the examples also get updated if there are some esp32 updates ?)

Everything works now when hooking up to OLED_SDA and OLED_SCL

tikard · November 27, 2021, 4:20am

Glad I found this. Was struggling to get other peripherals working on the LORA board.

Now on to the RTC…

zupayruna2021 · April 19, 2022, 4:28pm

I have problems with this example in my Wireless Stick Lite, the board always are rebooting with your code SD_Time.ino