Arduino Forum

Using Arduino => Installation & Troubleshooting => Topic started by: projectstowork1 on Dec 15, 2012, 06:10 am

Title: GND on Arduino Uno R3
Post by: projectstowork1 on Dec 15, 2012, 06:10 am
Hello:
    As I was trying out my new Arduino Uno R3 board, I found 3 pins that didn't have any white words beside it.
    Those 3 pins are located on the right of the reset button, on the left of the GND pin, and AREF is right beside it.
    Can anyone tell me what those 3 pins are?
    Thanks a lot.
   
Title: Re: GND on Arduino Uno R3
Post by: johnwasser on Dec 15, 2012, 06:15 am
There are six pins to the right of the reset button (two rows of three).  That's the ICSP header used for burning a new bootloader.
Title: Re: GND on Arduino Uno R3
Post by: projectstowork1 on Dec 15, 2012, 07:06 am
Thanks for your reply. But we have a slightly different Uno board.

My reset button is beside the USB port.

So are those 3 pins GND?
Title: Re: GND on Arduino Uno R3
Post by: retrolefty on Dec 15, 2012, 08:39 am

Thanks for your reply. But we have a slightly different Uno board.

My reset button is beside the USB port.

So are those 3 pins GND?


You have the Rev3 Uno board. http://arduino.cc/en/Main/ArduinoBoardUno
Those six pins (2x3) are the ICSP pins associated with the 16U2 AVR chip used to perform the basic USB serial converter function for the board. The pins are used if it's ever necessary to re-burn the firmware that the chip uses.

Lefty
Title: Re: GND on Arduino Uno R3
Post by: cmiyc on Dec 15, 2012, 05:07 pm

Thanks for your reply. But we have a slightly different Uno board.

Picture?
Title: Re: GND on Arduino Uno R3
Post by: retrolefty on Dec 15, 2012, 05:12 pm


Thanks for your reply. But we have a slightly different Uno board.

Picture?


This picture from the product page shows the reset switch location on the original Uno, Uno SMD, rev2, and current rev3.

http://arduino.cc/en/Main/ArduinoBoardUno

Lefty

Title: Re: GND on Arduino Uno R3
Post by: cmiyc on Dec 15, 2012, 05:16 pm
People have said "my board looks exactly like the Uno R3" and when they finally post a picture it is a Mega.


This picture from the product page shows the reset switch location on the original Uno, Uno SMD, rev2, and current rev3.

I asked for a picture because it seems to make more sense to see the actual board the OP is asking about.
Title: Re: GND on Arduino Uno R3
Post by: retrolefty on Dec 15, 2012, 05:18 pm

People have said "my board looks exactly like the Uno R3" and when they finally post a picture it is a Mega.


This picture from the product page shows the reset switch location on the original Uno, Uno SMD, rev2, and current rev3.

I asked for a picture because it seems to make more sense to see the actual board the OP is asking about.



Cool, I thought maybe you didn't know they did move the reset switch in the current Uno R3 board.
Title: Re: GND on Arduino Uno R3
Post by: johnwasser on Dec 15, 2012, 07:51 pm

Thanks for your reply. But we have a slightly different Uno board.

My reset button is beside the USB port.

So are those 3 pins GND?

http://www.arduino.cc/en/Main/arduinoBoardUno
"Revision 3 of the board has the following new features:

"1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible both with the board that use the AVR, which operate with 5V and with the Arduino Due that operate with 3.3V. The second one is a not connected pin, that is reserved for future purposes."

So the four pins nearest the reset button on the Arduino UNO R3 are:

SCL
SDA
AREF
GND

SCL and SDA are labeled on the bottom of the board.  AREF and GND are labeled on the top.
Title: Re: GND on Arduino Uno R3
Post by: projectstowork1 on Dec 16, 2012, 05:07 am
Thank you guys for answering my question!!

:P