Is it possible to use an Arduino UNO as a USB to TTL converter for unbricking a Seagate Barracuda 7200.11 Hard Drive
And if it is possible : how to program it?
The Arduino UNO has no FTDI chip.
In this video, they have done it with a Arduino clone with a FTDI chip : http://adaptorforrs232cserial.blogspot.com/2012/02/seagate-720011-hd-unbricking-with-mac.html
I just did yesterday that job of using Arduino Uno as a TTL to USB converter. Just put Arduino in Tristate mode and you don't need any sketch on it. The ATMega8U2 did the hard work!. Just follow these instructions: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1258845741
Thery're for Arduino Mega, but the logic is the same: put to ground the Reset Pin with a wire and the ATMega 328 will go in Tristate mode, so you can use directly its serial pins to communicate with your hard disk.
Only check accurately the ground and Vcc connection. I had a hard work to investigate why characters on the console arrived very dirt. The solution was to disconnect the AC adapter on my notebook and go only with battery. Perhaps the adapter did some intereference on ground between the pc and arduino.
On the Uno, the ATMega8U2 does the job of the FTDI. It converts USB serial to TTY level serial. Your hard disk apparently has a serial console, so connect the output of the 8U2 to the hard disk.
Make sure both devices are running at the correct voltage levels or that your have appropriate conversion.
Consult the Arduino Uno schematic for the pins to tap. Taking the ATMega328 out of the socket is probably the easiest solution.
