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Supported in ReprapFirmware 1.21 and later.

Parameters

• Pn SD slot number, default 0
• Sn Response format. S0 returns a plain text response, S2 returns a response in JSON format.

Examples:

• M39 ; report information for SD card 0 in plain text format
• M39 P1 S2 ; report information for SD card 1 in JSON format

This command returns information about the SD card in the specified slot in the requested format. At least the following is returned:

• Whether or not a usable card is present in the slot
• The capacity of the card in bytes (if a card is present)
• The amount of free space on the card in bytes (if a card is present)

The JSON response has the following format (this is provisional):

{"SDinfo":{"slot":0,"present":1,"capacity":4294967296,"free":2147485184,"speed":20971520}}

The capacity and free space are in bytes and the interface speed is in bytes/second.