Pages: [1]   Go Down
Author Topic: Replacement FTDI IC (ATMEGA8U2)  (Read 1516 times)
0 Members and 1 Guest are viewing this topic.
0
Offline Offline
Newbie
*
Karma: 0
Posts: 11
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I would like to replace the FTDI IC the ATMEGA8U2.
I am almost sure that that is why my arduino isn't reconised by my computer.
I already resolderd the ic but that hasen't helped. So I want to replace it by a new one.
Is is possible to just buy the ATMEGA8U2, or need it to be programed?
Logged

Austin, TX
Offline Offline
Faraday Member
**
Karma: 71
Posts: 6146
Baldengineer
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

The ATmega8u2 is not a FTDI.  "FTDI" is a brand of serial to USB chips. The ATmega8u2 is a general purpose microcontroller that is programmed to work as a serial to USB device.
Logged

Capacitor Expert By Day, Enginerd by night.  ||  Personal Blog: www.baldengineer.com  || Electronics Tutorials for Beginners:  www.addohms.com

the land of sun+snow
Offline Offline
Faraday Member
**
Karma: 159
Posts: 2916
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I already resolderd the ic

You must be very good to re-solder such a small smt pitch chip. Did you ever have it
working correctly in the first place? There are sometimes installation problems with the
drivers. I'm not sure how someone can fry only that chip on a board.
Logged

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 361
Posts: 17293
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I already resolderd the ic

You must be very good to re-solder such a small smt pitch chip. Did you ever have it
working correctly in the first place? There are sometimes installation problems with the
drivers. I'm not sure how someone can fry only that chip on a board.

Yes, very easy to do in the older arduino boards that used a FTDI chip. The shield 3.3v pin was supplied by the FTDI chip but was limited to 50ma output current or less and if one attempted to draw more then that or accidental shorted the 3.3v pin to ground the FTDI could be destroyed without damaging anything else on the board.

Lefty
Logged

the land of sun+snow
Offline Offline
Faraday Member
**
Karma: 159
Posts: 2916
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
if one attempted to draw more then that or accidental shorted the 3.3v pin to ground the FTDI could be destroyed without damaging anything else on the board.

Ah so. What about on the newer boards that have their own 3.3V v.reg? How do you fry
just the 8U2 or 16U2 chip?
Logged

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 361
Posts: 17293
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
if one attempted to draw more then that or accidental shorted the 3.3v pin to ground the FTDI could be destroyed without damaging anything else on the board.

Ah so. What about on the newer boards that have their own 3.3V v.reg? How do you fry
just the 8U2 or 16U2 chip?

Not sure there is a clear cut and repeatable method of just destroying the 8U2 or 16U2 chips without also subjecting other components to damage. Perhaps if one placed high voltage onto the USB D+ and/or D- pins?

Lefty
Logged

the land of sun+snow
Offline Offline
Faraday Member
**
Karma: 159
Posts: 2916
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
Perhaps if one placed high voltage onto the USB D+ and/or D- pins?
That doesn't seem very likely, unless the PC USB port was putting out high voltage.
How often does a PC USB port do that? They're probably fairly bulletproof, given the
hazards a PC faces day to day. Otherwise, OP would have to be sticking live wires into
the USB connector. Also, the UNO boards have some protection on the D+,D- pins.

I'd bet OP has some "other" problem, and has possibly wrecked the bd in the meantime
by resoldering the USB chip. I'd not want to try an resolder such a tiny pitch part.
Logged

Pages: [1]   Go Up
Jump to: