Removing inline resistor on Mini

Forum 2005-2010 (read only) Hardware Troubleshooting
1

Hi All,

I have a project using a mini for which I have had some issues. I have tracked the issue down to pin 13, and would assume that the inline 1k resistor is to blame.

My query is as follows:

can I simply remove the resistor and bridge the pads?
would this then make pin 13 act EXACTLY the same as other I/O pins?
is there any code in the Arduino bootloader which makes pin 13 act in any different way than the other I/O pins?

Thanks for the help. Before it is suggested, I can't relocate away from pin 13 as my PCBs are already manufactured and all I/O pins are used. I realise that the boot sequence has pin 13 raised high three times on start, but this should not effect me.

cheers!

2

can I simply remove the resistor and bridge the pads?

Yes I would remove it and bridge the pads. Does anyone know why it is there, it's not serving any function when it is operating. I think it is something to do with programming the boot loader. Make sure it is placed in any boot loader programming header you have.

3

probably so you can stick an LED on that pin without needing an external resistor.

It isn't needed for ICSP programming.

-j

4

Thanks guys.

Can anyone familiar with the Arduino bootloader confirm whether pin 13 is treated any differently than the other I/O lines besides the inline resistor?

5

The bootloader blinks pin 13, so I think it's left as an output (I think the default for the other pins in an input).

6

I'm pretty sure it's just there because traditionally pin 13 is the LED pin.