Sergio .... the question is what SD speeds does the Intel Edison module support? What is the fastest speed that the Edison Arduino shield will support?
In particular I'm designing a custom shield, and would like to support the fastest SD card that the Intel Edison module will support.
From Wikipedia: Secure Digital - Wikipedia, the free encyclopedia
Bus interface Card logo Bus logo Bus speed Spec version Default Speed — 12.5 MByte/s 1.01 High Speed 25 MByte/s 2.00 UHS-I 12.5 MByte/s (SDR12)
25 MByte/s (SDR25)
50 MByte/s (SDR50, DDR50)
104 MByte/s (SDR104)
3.01 UHS-II 156 MByte/s (FD156)
312 MByte/s (HD312)
High Speed is SD 2.0 .... UHS-1 is SD 3.0
Falling pack to high speed is a relatively trivial and straight forward exercise using one of the many level shifters solutions.
I'm still struggling with how to properly support the SD Spec 3.0 features that the Edison Mobile Hardware Guide section 4.2 says this device supports, which says:
4.2 SD card interface
An SD 3.0 compliant interface is available on pins 44, 58, 60, 62, 64, 66, 68, and 70.
SD memory key features:
• Host clock up to 50 MHz
• Supports card detection (insertion/removal) with dedicated card detection signal only.
• Meets SD Host Controller Standard Specification version 3.0.
• Only supports SD memory
• Requires external level shifter for support of 2.85 V devices
Could you be more specific about what is not working with the SD Host controller? Have you checked that the product you are trying to control has all the required Host drivers installed? Also, how can you tell that the application is not working, what error are you getting?