An0 as output oscillating

NETMF & Gadgeteer
1

I have a 5x5 keypad matrix that is scanned by setting the Columns high and then reading the Rows.

My problem is that on everything connected to Col 1 (An0) oscillates when it is read on any of the rows.

Is An0 different to the other pins when used as an output in some way?

I use the An pins as outputs because using An4 as digital input gives and argument exception when set as an InputPort.


        OutputPort _C1 = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.An0, false);
        OutputPort _C2 = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.An1, false);
        OutputPort _C3 = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.An2, false);
        OutputPort _C4 = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.An3, false);
        OutputPort _C5 = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.An4, false);

        InputPort _R1 = new InputPort((Cpu.Pin)FEZ_Pin.Digital.UEXT6, true, Port.ResistorMode.PullDown);
        InputPort _R2 = new InputPort((Cpu.Pin)FEZ_Pin.Digital.UEXT5, true, Port.ResistorMode.PullDown);
        InputPort _R3 = new InputPort((Cpu.Pin)FEZ_Pin.Digital.UEXT7, true, Port.ResistorMode.PullDown);
        InputPort _R4 = new InputPort((Cpu.Pin)FEZ_Pin.Digital.UEXT9, true, Port.ResistorMode.PullDown);
        InputPort _R5 = new InputPort((Cpu.Pin)FEZ_Pin.Digital.UEXT10, true, Port.ResistorMode.PullDown);

Any ideas?

2

An0 is same as any other pin