/********************************************************************/ /* */ /* Uarttst.cpp: Sample UART Loopback Test Program */ /* */ /* This program sends a stream of data to COM1 at regular time */ /* intervals specified by the value of the constant TIME_INTERVAL. */ /* Refer to the comments throughout the program for more details. */ /* */ /* (c)Copyright Sealevel Systems, Inc., 2001 */ /* */ /* SEALEVEL SYSTEMS INCORPORATED. */ /* 155 Technology Place */ /* P.O. Box 830 */ /* Liberty, SC 29657 USA */ /* (864) 843-4343 */ /* (864) 843-3067 FAX */ /* */ /********************************************************************/ #include #include #include #define STR_TO_DISP 6 // Number of test strings to use #define TIMEOUT_CONSTANT 5 #define ESC 27 #define STR_LENGTH 49 #define TIME_INTERVAL 50 // This is the counter that determines // the time interval between the outputs // of the test string. If you are // receiving hacked up data, you will // either need to increase this value or // the data rate (or both). See below for // more information. HANDLE WinStdOut = NULL; // Console Handle ////////////////////////////////////cursor()//////////////////////////////////// void cursor(int x_pos, int y_pos) { // Moves the cursor to the position specified by _curpos; COORD Newcurpos; Newcurpos.X = x_pos; Newcurpos.Y = y_pos; SetConsoleCursorPosition(WinStdOut, Newcurpos); }// cursor() ////////////////////////////////Erase_Screen()//////////////////////////////////// void Erase_Screen(void) { // Fills the section of the screen that prints received data with spaces. int c; char erasestr[81]; for (c = 0; c < 81; c++) erasestr[c] = ' '; // space erasestr[80] = '\0'; cursor(0, 8); for (c = 8; c < 24; c++) printf(erasestr); }// Erase_Screen() ////////////////////////////////////main()///////////////////////////////////// int main(void) { int cur_str = 0; // Current test string to send int timer = TIME_INTERVAL; int key_pressed = 0; char teststring[6][STR_LENGTH]; char rec_str[STR_LENGTH]; bool bStatus; int x_pos = 0, y_pos = 8; DWORD bytes_written = 0; // Number of bytes written to port DWORD bytes_read = 0; // Number of bytes read from port HANDLE comport = NULL; // Handle for COM port DCB comSettings; // Contains various port settings COMMTIMEOUTS tempComTimeouts; // Our temporary time-outs for COM1 COMMTIMEOUTS savedComTimeouts; // Stores the original time-outs CONSOLE_SCREEN_BUFFER_INFO consoleInfo; // Used to get cursor position. strcpy(teststring[0], "The quick brown fox jumped over the lazy dog. \n\r\0"); strcpy(teststring[1], "(c)Copyright Sealevel Systems Inc., 1999. \n\r\0"); strcpy(teststring[2], "abcdefghijklmnopqrstuvwxyz1234567890()+;.,-/< \n\r\0"); strcpy(teststring[3], "This program created with Microsoft Visual C++\n\r\0"); strcpy(teststring[4], "On an Intel Pentium with 32 megs of RAM. \n\r\0"); strcpy(teststring[5], "rig rIg riG rIG Rig RIg RIG RiG \n\r\0"); printf("Sample UART Loopback Test Program.\n"); printf("(c)Copyright Sealevel Systems, Inc., 1999.\n\n"); // Open COM port if ((comport = CreateFile("\\\\.\\COM1", GENERIC_READ | GENERIC_WRITE, // for reading and writing 0, // exclusive access NULL, // no security attributes OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) { printf("Unable to open COM1.\n\n"); printf("Press any key to exit."); getch(); return(1); } printf("COM1 opened.\n\n"); WinStdOut = GetStdHandle(STD_OUTPUT_HANDLE); // Save time-out parameters for COM1 bStatus = GetCommTimeouts(comport,&savedComTimeouts); if (bStatus == 0) { printf("GetCommTimeouts failure.\n\n"); printf("Press any key to exit."); getch(); return(1); } // Set our time-outs. // When ReadIntervalTimeout and ReadTotalTimeoutMultiplier are // set to MAXDWORD and ReadTotalTimeoutConstant is a value // greater than 0 and less than MAXWORD, the following occurs // when ReadFile() is called: // // - If there are any characters in the input buffer, ReadFile() // returns immediately with the characters in the buffer, instead // of waiting until the end of the transmission. // // - If there are no characters in the input buffer, ReadFile() // waits until a character arrives and then returns immediately. // (Again without waiting until the end of the transmission.) // // - If no character arrives within the time specified by // ReadTotalTimeoutConstant, ReadFile times out. // // Information obtained from the "COMMTIMEOUTS" section of the // MSDN Library. tempComTimeouts.ReadIntervalTimeout = MAXDWORD; tempComTimeouts.ReadTotalTimeoutMultiplier = MAXDWORD; tempComTimeouts.ReadTotalTimeoutConstant = TIMEOUT_CONSTANT; tempComTimeouts.WriteTotalTimeoutMultiplier = TIMEOUT_CONSTANT; tempComTimeouts.WriteTotalTimeoutConstant = TIMEOUT_CONSTANT; bStatus = SetCommTimeouts(comport,&tempComTimeouts); if (bStatus == 0) { printf("SetCommTimeouts failure.\n\n"); printf("Press any key to exit."); getch(); return(1); } // Set Port parameters. // We make a call to GetCommState() first in order to fill // the comSettings structure with all the necessary values. // Then we change the ones we want and call SetCommState(). bStatus = GetCommState(comport, &comSettings); if (bStatus == 0) { printf("GetCommState failure.\n\n"); printf("Press any key to exit."); getch(); return(1); } comSettings.BaudRate = CBR_9600; comSettings.StopBits = ONESTOPBIT; comSettings.ByteSize = 8; comSettings.Parity = NOPARITY; comSettings.fParity = FALSE; bStatus = SetCommState(comport, &comSettings); if (bStatus == 0) { printf("GetCommTimeouts failure.\n\n"); printf("Press any key to exit."); getch(); return(1); } printf("Sending string: "); printf("\n\nReceived: "); while(key_pressed != ESC) { if (kbhit()) key_pressed = getch(); //Send data. if succesful, WriteFile() returns non-zero if ((timer == TIME_INTERVAL)) { cursor(16,5); printf(teststring[cur_str]); WriteFile(comport, // Handle &teststring[cur_str], // Outgoing data STR_LENGTH, // Number of bytes to write &bytes_written, // Number of bytes written NULL); if (cur_str++ == (STR_TO_DISP - 1)) cur_str = 0; timer = 0; } // Read data. // Because of the way the time-outs are set (see above), // Readfile() will actually never read the whole string in // one call. Rather, it receives the data in chunks which // is then printed to the console. If TIME_INTERVAL is too // small or the data rate too slow, Readfile() will not have // time to read all the data before more is sent. // If succesful, ReadFile() returns non-zero ReadFile(comport, // Handle &rec_str, // Incoming data STR_LENGTH, // Number of bytes to read &bytes_read, // Number of bytes read NULL); if (bytes_read >= 1) { rec_str[bytes_read] = 0; if (y_pos == 24) { y_pos = 8; Erase_Screen(); } cursor(x_pos, y_pos); printf("%s", rec_str); GetConsoleScreenBufferInfo(WinStdOut, &consoleInfo); x_pos = consoleInfo.dwCursorPosition.X; y_pos = consoleInfo.dwCursorPosition.Y; } timer++; } // Restore time-out parameters SetCommTimeouts(comport,&savedComTimeouts); CloseHandle(comport); cursor(0, y_pos + 2); return(0); }// main()