Hardware muxed SD Cards

While working on a customer project to do safe Raspberry Pi remote updates (in software), I got curious about the potential of doing this in hardware.

Here, I’m multiplexing two SD cards into a single Raspberry Pi using a ts3a27518e, http://www.ti.com.cn/cn/lit/ds/symlink/ts3a27518e.pdf

Of course, fast SD card signals aren’t happy with breadboards and long dangly wires. But, it does actually work at low speeds.