rpi microSD slot

예전에 eMMC 어댑터를 이용해서 rpi에 연결했을때

깜박이지도 않았는데

SD.CARD.DET 핀 자체가 탐지되지 않으면 SD가 없는걸로 간주하고 배째는게 아닐까 싶은데

(그러니까 핀인식이 안되면 SD 읽을 시도조차 하지 않음?)

나중에 머라도 덧대서 한번 다시 시도는 해봐야 할 듯?

[링크 : https://www.raspberrypi.org/.../Raspberry-Pi-Rev-2.0-Model-AB-Schematics.pdf]

[링크 : http://electronics.stackexchange.com/.../how-can-i-hardware-protect-a-microsd-from-writing-to]

Check the ACT LED to determine if the Pi is booting The ACT LED is essential in determining if the Pi can actually read from the card. It indicates that it can read from the card by blinking, If the ACT LED doesn't blink quickly in an irregular pattern for at least twenty seconds, this indicates that the Pi cannot read from the SD card, and that booting is not taking place. By the way, It doesn't matter if the ACT LED initially starts on or off. It is only the blinking of the ACT LED that is significant. A dim ACT LED also has no significance beyond the fact that you are using a B. From the model B+ onwards, the LED is driven differently, and it wont be dim. With no SD card inserted, note how the ACT LED behaves (hint, it won't blink!). Now insert a programmed card and that behaviour should change. If it does not, this indicates that Pi cannot see the necessary files on the SD card. For a demonstration, watch this video of a model B: the ACT LED is the one on the left-hand side. Note that on later models the ACT LED will start on on power up, instead as off like the model B.  With working firmware, Meaning the PI can read files from the card, the ACT LED will flicker intermittently for 20-30 seconds. The LED is actually driven by the software read from the card using a dedicated GPIO pin turning it on whenever the card is read. It can also blink in a regular "Morse" pattern, which usually indicates an error condition. See the Additional Information section at the end of this post for details.

[링크 : https://www.raspberrypi.org/forums/viewtopic.php?t=58151]