Can I use an USB pendrive as MMC card for a digital camera?

A pile of flash drives I gathered inspired me to ask this question. I know you can connect an MMC card to USB socket using a simple adapter. But is it possible to make an "inverted" adapter, that would allow me to use a flash drive as MMC card for my camera? I guess it wouldn't be as simple as etching a MMC-shaped PCB and wiring it to an USB socket, and almost certainly it would require some advanced electronics... The next issue I worry about is writing speed of a pendrive. Would it be sufficient for a camcorder? I was unable to find any ready solution of this problem and I find it strange that nobody has tried it before...

frollard4 years ago
Simply put, no.

USB is an electrical and software protocol, universal serial bus, a language with which to 'speak' between peripherals. It's like how sound can be used to transmit english and german and french speech, usb can be used to transmit LOTS of data packets that conform to many protocols.

MMC uses its own protocol (SDIO or SPI) to talk to the camera directly. It so happens that MMC cards are ALSO able to 'talk' USB in order to easily connect with computers -- but that does not mean usb speaks SDIO or SPI protocol.

If your camera attempts to connect to a usb thumbdrive with SPIO or SPI it will simply not work or potentially damage each other.