sd card emulation

Pleased to discover there are ready to use, non-emulation SD card mux devices available!

These are great for 99% of the use cases folks message me about.

https://wiki.tizen.org/SDWire

SD Wire

https://www.tindie.com/products/badgerdnl/sdwire-usb-c-sd-card-reader-sd-mux/ ~ $95

https://3mdeb.com/shop/open-source-hardware/sdwire/ ~ 89 €

USB-SD-Mux from Linux Automation GmbH ~ 100 €

https://shop.linux-automation.com/usb_sd_mux-D02-R01-V02-C00-en


Although utilizing SD emulation as this project does, provides benefits such as speed and durability, the related costs and complexity outweigh these advantages. It only makes sense to use SD emulation if the cost of not having these features is higher.

For ready-to-use applications check out the SD Card Wifi Adapter.

caveat: It uses SPI mode (low speed) so Its slow and sometimes glitch-y.

BOM

One goal of this project was to be accessible to lots of people. The total BOM cost using off the shelf components is < $100 (USD):

* (micro)SD card extender

* FPGA [ know of an open source FPGA that works here? Please share! ]

Here's a brief how to:

(1) Connect your (micro)SD card extender to your FPGA pins

(1) b. Map out your pins

(2) Load up the open source SD card emulator onto your FPGA

(3) A driver on the host machine that can do 3 things:

     Read

     Write

     lock / unlock the device

open source release coming soon

Fun fact: Consultants quoted this project between $25k and $250k and anywhere from 3 months - 18 months. No one could guarantee it would work..

Here is open-source code if you're interested in doing this yourself: https://github.com/enjoy-digital/litesdcard/blob/master/examples/arty.py#L109 (Thanks to Florent @ Enjoy-Digital + Ramtin and PO @ Lamda Digital for making this available)

Should work on any capable FPGA,  Altera and Xilinx are what we have here.

Detailed update to follow.