[En-Nut-Discussion] Problem with Ethernut-Board: Pin 3 on PortB

[Harald Kipp]

Hi Roman,

Roman Walpuski wrote:
> I have a problem with pin 3 at PortB. Whenever i set pin 3 and pin 4 to high, 
> voltage on pin3 drops to ca 1 volts. when pin4 is not set to high, everything is fine. 

Please have a look to

http://www.ethernut.de/en/hardware/enut2/ports.html

PB1, PB2 and PB3 are used by SPI. PB4 is the positive chip select of the
only on-board SPI slave, the serial Dataflash chip. Setting PB4 to high
will select this chip and enable its output connected to PB3.

You should avoid to use PB1-PB3 for GPIO. If you need to, you must keep
PB4 low.

If you don't need the Dataflash at all, you may cut the trace coming
from the Via near IC11 pin 1. R7, a pull-down, will keep pins 1 and 2
low and you can use PB4 for GPIO too (schematic page 2).

Harald