Digital I/O ReadFile throw NotSupportedException

korbai · May 19th 2009

Hi,

I tried to read digital input but I always got NotSupportedException
during ReadFile call (CreateFile / WriteFile works, I can set/clear digital outputs).
I set registry for input/output pins. (keyboard matrix works, dig. output works, pwm works)

Is it really not supported? Or I missed something?

Thanks,
Zoltan

kernel: NK10_CF2_090121.bin

Code

byte[] buffer = new byte[3];
uint num = 0;
IntPtr h = CreateFile("DIO1:", GENERIC_READ | GENERIC_WRITE, 0, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
int result = CEWriteFile(h, buffer, (uint)buffer.Length, ref num, IntPtr.Zero);
result = CEReadFile(h, ref buffer, (uint)buffer.Length, ref num, IntPtr.Zero);
//' Write File()
[DllImport("coredll.dll", EntryPoint = "WriteFile", SetLastError = true)]
static extern int CEWriteFile(
IntPtr hObject,
byte[] lpBuffe,
uint NumberOfBytesToWrite,
ref uint lpNumberOfBytesWritten,
IntPtr lpOverLapped);
//'Read File()
[DllImport("coredll.dll", EntryPoint = "ReadFile", SetLastError = true)]
static extern int CEReadFile(
IntPtr hObject,
ref byte[] lpBuffer,
uint NumberOfBytesToRead,
ref uint lpNumberOfBytesRead,
IntPtr lpOverLapped);

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fs-support_ZU · May 20th 2009

Hello, i suggest "read" is supported.
does following work?

Code

Byte[] Data = new Byte[1];
Int32[] Read = new Int32[1];
if (ReadFile(hPort, Data, 1, Read, IntPtr.Zero) > 0)
{
...
}
[DllImport("coredll.dll", EntryPoint = "ReadFile", SetLastError = true)]
public extern static uint ReadFile(IntPtr hObject, Byte[] lpBuffer, uint NumberOfBytesToRead, Int32[]
NumberOfBytes, IntPtr lpOverLapped);

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Are the "defines" correct?

Code

const UInt32 GENERIC_READ= 0x80000000;
const UInt32 GENERIC_WRITE = 0x40000000;

korbai · May 20th 2009

Thanks, it works. So my ReadFile signature was the reason.
BTW it will be helpful if the documentation contains ReadFile sample
like WriteFile sample in digital i/o section.

It is normal that I can read only 1 byte on each ReadFile call?
I tried to read all pins (3 bytes) but the return value and the
'Read[0]' variable is the same: 1.

fs-support_ZU · May 20th 2009

Quote

It is normal that I can read only 1 byte on each ReadFile call? ...

Yes, use "SetFilePionter()" for jump to an other port.

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