The development board not detect SD card
That SBC is almost 10 years old, designed for Windows CE 6.0. It most likely cannot support SDHC (Secure Digital High Capacity) cards, or does not support fat32, or both. SDSC (Standard Capacity) and FAT16 were originally designed for 2GB max partition/capacity, later patched to 4GB if your device supported it. SDHC and FAT32 support up to 32GB. SDHC is not backwards compatible with SDSC.