How to program a Uno with another Uno (New to Arduino)

Other Hardware 3rd Party Boards
1

I fried one of my 16U2 on one of my Uno.
And now Im trying to learn how to program Uno using another Uno or Mega (I have both).
I have been looking around on the internet looking for solutions.
I found some one had similar problem before, here are some links that I use to try to solve the problem:

But after I try to do it myself I kept running into problems says

avrdude: stk500_getsync(): not in sync: resp=0x00

I saw something like I have to put a capacitor between reset and 5V.
I tried and it still gives me nothing.

Using above posts and now I am a bit confused. I do not know what I am doing or where I did wrong.
I followed every step and I still dont know how to do it.
I am completely lost.

2

To use USB interface of good arduino to download a program into another bootloaded Arduino:
Connect 5V to 5V, Gnd to Gnd, Tx to Tx, Rx to Rx.
On good arduino, connect Reset to Gnd.
Star the download - when IDE shows "compiled xxx of 32xxx bytes" press Reset on the 2nd arduino.
Have verbose outputs turned on under File:Preferences" can make it easier to get the reset timing correct.

3

CrossRoads:
To use USB interface of good arduino to download a program into another bootloaded Arduino:
Connect 5V to 5V, Gnd to Gnd, Tx to Tx, Rx to Rx.
On good arduino, connect Reset to Gnd.
Star the download - when IDE shows "compiled xxx of 32xxx bytes" press Reset on the 2nd arduino.
Have verbose outputs turned on under File:Preferences" can make it easier to get the reset timing correct.

So on the good arduino I just need to put a jump wire from Reset to Gnd? no capacitor needed?

4

I used these instructions without any problems.

...R

5

No capacitor needed. It will be the same as if you took the chip out of the board.

6

antonio6510:
I fried one of my 16U2 on one of my Uno.

Are you sure you have not simply scrambled it? Using the ISP (ICSP) header adjacent to "J2" and the 16U2, you may be able to re-flash it using the other UNO as ISP.

If it really is fried, then go get a proper USB to TTL adapter and use that instead of another UNO. You will still need the 0.1µF capacitor from DTR of the adapter to Reset.

7

Robin2:
I used these instructions without any problems.

...R

I tried this one too... But still didnt work....

8

CrossRoads:
No capacitor needed. It will be the same as if you took the chip out of the board.

Im still trying to figure out where i did wrong because Im still getting the error :
avrdude: stk500_getsync(): not in sync: resp=0x00

9

[/quote]

Are you sure you have not simply scrambled it?

[/quote]

Yea.... unfortunately I tried to reset the 16U2 and didnt work out... found out I actually fried it

10

Could be the dead one is dragging down the lines. You could isolate it by removing RN4, which is the little 8-pin package next to the ICSP header; need to add a 1K resistor from the inside leg of the ON LED to +5 to show power is on. Or remove the 16U2 if you decide it really is bad (i.e. programming it doesn't work).