My SD shield works nicely on 5v supply, but does not detect SD card on 3.3v. Could someone explain the possible reason behind this? Could you also provide a solution for this?
I've worked with it on Arduino Uno. Now I want to use SD card directly with ESP-12E to read its contents using SPI by doing something like this. Since ESP8266 operates olny on 3.3v, I need SD card to work on this voltage.
I've used two separate SD card shields without any luck! Photos of the two shields and micro-SD card are attached.