Digital I/O Pin 4 Sinking to GND

The EtherTen combines an Uno-equivalent Arduino-compatible board and Wiznet-based Ethernet support, along with a microSD card slot and Power-over-Ethernet support. [Product page]
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Schoonerburger
Posts: 2
Joined: Tue Aug 14, 2012 3:55 am

Digital I/O Pin 4 Sinking to GND

Post by Schoonerburger » Tue Aug 14, 2012 4:09 am

Hi

I have a EtherTen Arduino board and I have noticed that PIN 4 when used as an INPUT drags down the supply to it when using a Pull Up Resistor setup.

as shown for example here

http://www.roguescience.org/wordpress/b ... xercise-6/

I have tried using this Joystick input shield

http://www.dfrobot.com/index.php?route= ... CnL4KOLsrN

and when testing the inputs I noted that button C (input 4) didn't work.

when I looked at the schematic I noticed that the setup in the shield is using pull up resistors

http://www.dfrobot.com/wiki/images/5/5a ... ld_Sch.png

instead of just plugging the shield into my etherten I jumpered over the 5v supply, GND, and the button inputs but moved input 4 to another input for example input 8 and tested and all buttons working fine.

My thinking was that this was an issue with my etherten board and spoke to the guys at Jaycar and they sorted me out with a new one, when I got it home and tested it it ... same problem, my thinking is that this is a common issue ?

Just wondering if this is known about ? and if there is a solution.

I understand that the input can be used if you setup a pull down resistor setup, and it works ok for an output

Thanks for your help in advance

Schoonerburger
Posts: 2
Joined: Tue Aug 14, 2012 3:55 am

Re: Digital I/O Pin 4 Sinking to GND

Post by Schoonerburger » Tue Aug 14, 2012 4:15 am

Just had a look at the schematic for the etherten and noted on page 3 that:

D4 used by microSD card Chip Select

just wondering if that has something to do with my issue ?

and on page 2 it looks like D4 is tied to ground via a 1K resistor (RN6D) and a 2.2K resistor (RN8A)

I'm thinking thats why I'm having issues ?

Thanks again for your help

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