is there a pcb layout recommendation for manufacturer who wants make an ESP8266 SDHC Module ,
or adapt an SDHC holder interface
example without a spi flash ic, only use sdhc card -
example with combine a spi flash ic - with 'hardware' boot choice by solder pad.
are there general recommendation for manufacturer from espressif using sdhc ?
txs
best wishes
rudi

my found for test sdhc & esp8266ex module was
adapter: http://www.ebay.de/itm/171168414356
just in time, there is a german manufacturer who build new module for me -
i will use this in a new ESP8266 Module with SDHC ( 32 GB )
holder: http://www.ebay.de/itm/171738462758
@AI Thinker Team
Are you planning to bring out a module with SDHC?
example SDHC in (H) SPI Mode...
Credit for (H) SPI goes
costaud
metalphreak
example
Found HSPI Overlap Mode by 'costaud'
viewtopic.php?f=15&t=56
Found (H)SPI driver by 'metalphreak'
Have a look to the MCP23S17 Portextender ( 2x8GPIO )
viewtopic.php?f=15&t=422
The FAT32 credit goes to elm chan

http://elm-chan.org/fsw/ff/00index_e.html
and the rest all was not difficult to bring together
Example code for LUNA
ESP8266 Module with a SDHC 32GB you will found here:
http://www.mikrocontroller.net/topic/370665#4222927
File: http://www.mikrocontroller.net/attachme ... _fat32.zip
SDHC 32 GB in (H)SPI example:
MOSI.. GPIO 13
MISO.. GPIO 12
CLK... GPIO 14
CS.... GPIO 15 !