Hi Pavel,
here is my (Delphi-)code. It is a thread, which waits for data from USB-VCP and, depending from the protocol, it tries to read more or less (aBufLen) data bytes.
Reading data is done by asynchronous file i/o (using overlapped struct) to let the thread sleep (WaitForSingleObject), when no data is received from device.
When enough bytes are received, the data protocol (CRC or else) will be checked and payload extracted.
The data istself is a properity protocol. I expect no issues with that. Just some bytes in an specific order.
The bluescreen comes without any user action. Just a (overnight) running process and sometimes in the morning bluescreen is presented.
But I also had the bluescreen, when running my program in debugger and just waiting for specific sensor data.
The program is a recording app, which receives and stores data, which comes from several sensors (STM32 board, O2 / CO2 sensors).
It maybe some packes per second but also some hundred packets per second. Each packet about 10 ... 150 Bytes.
Current bluescreens happens with only few packets per second.
As far i know, only the *.inf file is STM specific. The usbser.sys is Mircosoft.
Knut
function TCommO.CommReadA(var aBuf; aBufLen: Cardinal; aTimeOutMS: DWORD): Cardinal;
var
BytesInBuf: Cardinal;
begin
result := 0;
if Not CommIsOpen() then exit;
BytesInBuf := CommBytesInRxQueue(); // Windows Buffer
if (BytesInBuf = 0) then
aBufLen := 1 // if buffer empty, wait for the first char (continue reader thread does not make sense), but receive complete in next call
else
if BytesInBuf < aBufLen then aBufLen := BytesInBuf; // try to receive all, but consider buffer size
if Not ReadFile(m_CID, aBuf, aBufLen, result, @m_Ovl_Read) then
begin
if GetLastError() = ERROR_IO_PENDING then
begin
WaitForSingleObject(m_Ovl_Read.hEvent, aTimeOutMS);
GetOverlappedResult(m_CID, m_Ovl_Read, result, FALSE);
if result = 0 then
begin
if GetLastError() = ERROR_IO_INCOMPLETE then
CancelIo(m_CID);
end;
end
else
begin
CommError();
end;
end;
end;
function TCommO.CommBytesInRxQueue(): DWORD;
var
err: Cardinal;
MaxLoop: Cardinal;
stat: COMSTAT;
begin
result := 0;
If CommIsOpen() Then
begin
MaxLoop := 100;
repeat
ClearCommError(m_CID, err, @stat);
Dec(MaxLoop);
until (err = 0) OR (MaxLoop = 0);
if MaxLoop > 0 then
result := stat.cbInQue
else
Result := 0;
End;
End;
