currently I try to sent 720 bytes from Windows application to custom STM32 device (now for testing purposes I use Blue Pill - STM32F103xxx). Ah, I forgot to point that I am totally newbie into programming :). So on device side I have 1000 bytes buffers for receiving and sending (Thanks to STMCube for this). Testing device with terminal program ( packets < than 64 bytes) works. Then I rework one of Microsoft examples to be able to sent more data to device. Used device driver on Windows is "usbser.sys". In short my console program do following:
- Calculate SINE weave (360) samples - 16 bytes size
- Sent them to USB Device as 720 bytes (byte size protocol for COM port)
My problem is that no more than 64 bytes comes into device.
Somewhere I read that reason for this can be into built in Rx,Tx Windows buffers (64 bytes long by mention somewhere on internet) and for this into code below I insert:
- SetupComm(hCom,1000,1000) in hope that this will solve my troubles but nope. Below is "my" code, any ideas how I can fix this?
#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <math.h>
#define PI 3.14159265
void PrintCommState(DCB dcb)
{
// Print some of the DCB structure values
_tprintf(TEXT("\nBaudRate = %d, ByteSize = %d, Parity = %d, StopBits = %d\n"),
dcb.BaudRate,
dcb.ByteSize,
dcb.Parity,
dcb.StopBits);
}
int _tmain(int argc, TCHAR* argv[])
{
DCB dcb;
HANDLE hCom;
BOOL fSuccess;
const TCHAR* pcCommPort = TEXT("COM3"); // Most systems have a COM1 port
unsigned __int8 aOutputBuffer[720];// Data that will sent to device
unsigned __int16 aCalculatedWave[360];// Data that will sent to device
int iCnt; // temp counter to use everywhere
for (iCnt = 0; iCnt < 360; iCnt = iCnt + 1)
{
aCalculatedWave[iCnt] = (unsigned short)(0xFFFF * sin(iCnt * PI / 180));
if (iCnt > 180) aCalculatedWave[iCnt] = 0 - aCalculatedWave[iCnt];
}
// 16 bit aCalculatedWaveto to 8 bit aOutputBuffer
for (int i = 0, j = 0; i < 720; i += 2, ++j)
{
aOutputBuffer[i] = aCalculatedWave[j] >> 8; // Hi byte
aOutputBuffer[i + 1] = aCalculatedWave[j] & 0xFF; // Lo byte
}
// Open a handle to the specified com port.
hCom = CreateFile(pcCommPort,
GENERIC_READ | GENERIC_WRITE,
0, // must be opened with exclusive-access
NULL, // default security attributes
OPEN_EXISTING, // must use OPEN_EXISTING
0, // not overlapped I/O
NULL); // hTemplate must be NULL for comm devices
if (hCom == INVALID_HANDLE_VALUE)
{
// Handle the error.
printf("CreateFile failed with error %d.\n", GetLastError());
return (1);
}
if (SetupComm(hCom,1000,1000) !=0)
printf("Windows In/Out serial buffers changed to 1000 bytes\n");
else
printf("Buffers not changed with error %d.\n", GetLastError());
// Initialize the DCB structure.
SecureZeroMemory(&dcb, sizeof(DCB));
dcb.DCBlength = sizeof(DCB);
// Build on the current configuration by first retrieving all current
// settings.
fSuccess = GetCommState(hCom, &dcb);
if (!fSuccess)
{
// Handle the error.
printf("GetCommState failed with error %d.\n", GetLastError());
return (2);
}
PrintCommState(dcb); // Output to console
// Fill in some DCB values and set the com state:
// 57,600 bps, 8 data bits, no parity, and 1 stop bit.
dcb.BaudRate = CBR_9600; // baud rate
dcb.ByteSize = 8; // data size, xmit and rcv
dcb.Parity = NOPARITY; // parity bit
dcb.StopBits = ONESTOPBIT; // stop bit
fSuccess = SetCommState(hCom, &dcb);
if (!fSuccess)
{
// Handle the error.
printf("SetCommState failed with error %d.\n", GetLastError());
return (3);
}
// Get the comm config again.
fSuccess = GetCommState(hCom, &dcb);
if (!fSuccess)
{
// Handle the error.
printf("GetCommState failed with error %d.\n", GetLastError());
return (2);
}
PrintCommState(dcb); // Output to console
_tprintf(TEXT("Serial port %s successfully reconfigured.\n"), pcCommPort);
if (WriteFile(hCom, aOutputBuffer, 720, NULL, 0) != 0)
_tprintf(TEXT("720 bytes successfully writed to Serial port %s \n"), pcCommPort);
else
_tprintf(TEXT("Fail on write 720 bytes to Serial port %s \n"), pcCommPort);
return (0);
}
