I don't have any experience with arduinos so please excuse my ignorance, but I was hoping to get a little feedback on the feasibility of a project. I've done some googling but can't seem to come up with any projects along these lines...
I want to use an arduino micro to control access to data stored on a micro sd card (connected via a micro sd breakout board). The arduino would be connected to a computer via a micro usb to usb adapter.
The idea is that when the arduino device is inserted into any computer the user would have x seconds to input a specific key sequence. If the key sequence is not entered within x seconds, the arduino would overwrite the data on the micro sd card.
If the key sequence is entered within x seconds, the data stored on the sd card would be available to the user for read/write actions like a normal thumb drive would be.
I'd appreciate any input/constructive criticism.
Thanks in advance!
when the drive is inserted into the computer
What drive? Which computer?
jremington:
What drive? Which computer?
Sorry for the confusion. I've edited the original post. I meant when the arduino device was connected to the computer.
Are you familiar with what happens (what processes run, and what results are expected) on a PC or Mac when you plug a USB cable into the PC/Mac USB port?
Are you familiar with what the device on the other end of the USB cable has to do?
It could be done. You connect the Arduino, and it instantiates as a HID or Serial device and waits for a password to be sent. If the correct password is received, it switches to a storage device and lets windows bring it up as a disk. I don't particularly like the idea of erasing the data based on time, but you can certainly avoid "looking" like a disk...
I see two other problems:
- The 32u4 microcontroller is at best a "full speed" (12Mbps) device, so it's going to be quite slow compared to most USB disks that you're used to (480Mbps "High Speed", or better.) It's also not very well suited toward doing even "full speed" with much efficiency.
- Fitting all that code in 32k of program space might be difficult.
See Programming Arudino as USB mass storage device - Project Guidance - Arduino Forum
You might have problems using the SD card as a "raw" block device, which I think would be required?
An interesting strategy would be to have the arduino WITHOUT a correct password show different files than if you gave it a correct password...