For encrypting some online transactions, I am using a PC connected USB key. A transaction never takes more than a minute or so, and for security reasons, this USB key then needs to be removed once transaction completed, or hackers could perform transactions if they have control over my PC, especially when I am not in front of the PC.
That continuous having to plug and unplug the USB key is bothering me, and I would like to make a small box in which this USB key is plugged in. It has a button, and when pressed on this button, the USB key (data bus) will be activated for approx. 2 minutes, and then automatically disable the USB data bus again. So the only thing I need to do just before performing the transaction, is single press the button, and forget about it.
As I lack the time to build it myself, I am looking for a freelancer who can design the schematic and PCB layout. Both schematic and layout MUST be natively drawn in ALTIUM or CIRCUITSTUDIO, and please advise both application and version you will be using while bidding. Converted files from other packages will not be accepted. Simulation could also be performed with LTSpice.
Functional description: A monostable multivibrator, build with MC74VHC1G132 (SOT353) smith trigger NAND gate (as I have those in stock), will be triggered by a single press of a button, this will activate a 2x2 USB SWITCH (a FSUSB30MUX, also already in stock). The state should remain active for a good 2 minutes, the time needed to approve an online transaction. All this will be powered from USB, which will be hard-wired to the device and permanently connected to my PC. Being able to provide a simulation model of the monostable multivibrator section would be a plus.
I assume you have sufficient knowledge to connect and select/add the remaining components to make it to a working schematic. I would like to review and approve schematic and simulation model prior to start of layout.
This is not an urgent project, but I care about good craftsmanship and attention to (functional) detail. Un-careful component placement or sloppy routing will be returned to sender…
MC74VHC1G132 => [login to view URL]
FSUSB30MUX => [login to view URL]
17 фрилансеров(-а) готовы выполнить эту работу в среднем за $279
Hi, I have almost 15 years of experience. I have read the details and have a few questions. Please get back to me to discuss it further. Thanks
I have more than 9 years experience in embedded hardware design with eagle and altium design software with lt spice simulation also . So I can do your job within a time limit with your satisfaction.