With ESP-32, Wi-Fi network credentials (SSID and password) stored in SD Card with CSV can be read from SD Card. But when I tried to use these two values to connect to local network, ESP-32 can not access to the network. I am new to the programming and can not figure out why. Could you please help me with few lines of codes? Any book or article to read?
Please check this tutorial: https://randomnerdtutorials.com/esp32-wi-fi-manager-asyncwebserver/
That tutorial uses SPIFFS. But, you can replace the SPIFFS functions with SD card functions, and it should work.
For read/write functions for the SD card, check this example: https://github.com/espressif/arduino-esp32/blob/master/libraries/SD/examples/SD_Test/SD_Test.ino
You’ll see it’s very similar with the SPIFFS functions.
I hope this helps.