---
tag: m0021
title: Init SD card
brief: Attempt to detect an SD card in the slot.
author: thinkyhead

group: sdcard
requires: SDSUPPORT

codes: [ M21 ]
related: [ M22 ]

examples:

- pre: Init card with success
  code:
  - "> M21"
  - SD card ok
  - ok

- pre: Init card with failure
  code:
  - "> M21"
  - No SD card
  - ok

---

Use this command to mount the last-selected SD card or thumb drive.
