Repartitioning the miniSD

1. Clean up the card:

# dd if=/dev/zero of=/dev/sdx
(the 'no space left on device' error is ok)

2. Partition it:

# fdisk /dev/sdx
Create a new partition, leaving some room for EOL:
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
Partition number (1-4): 1
First cylinder (2-993, default 2): 10
Last cylinder or +size or +sizeM or +sizeK (10-993, default 993):
Using default value 993

Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 1
Changed system type of partition 1 to 1 (FAT12)

Command (m for help): p

Disk /dev/sdc: 14 MB, 14745600 bytes
1 heads, 29 sectors/track, 993 cylinders
Units = cylinders of 29 * 512 = 14848 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1              10         993       14268    1  FAT12

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
Syncing disks.

3. Format it:

$ mkfs.vfat -F 32 /dev/sdx1