gistfile1.cpp

/*
 * main.cpp
 *
 *  Created on: 08.12.2012
 *      Author: sk
 */

#include <iostream>
#include <windows.h>

using namespace std;

LPCSTR PORTNAME = "COM3";
const int n = 17-2; // -2 for removing sync0 bytes from struct

struct modeeg_packet
{
#if 0
        // These will be searched for in code
	uint8_t		sync0;		// = 0xA5
	uint8_t		sync1;		// = 0x5A
#endif
	uint8_t		version;	// = 2
	uint8_t		count;		// packet counter. Increases by 1 each packet
	uint16_t	data[6];	// 10-bit sample (= 0 - 1023) in big endian (Motorola) format
	uint8_t		switches;	// State of PD5 to PD2, in bits 3 to 0
};

HANDLE initSerial() {
	HANDLE hSerial = CreateFile(PORTNAME, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);

	if (hSerial == INVALID_HANDLE_VALUE) {
		cerr <<
				"Failed to read from port" << endl <<
				GetLastError() << endl;
	}

	DCB dcbSerialParams = {0};
	dcbSerialParams.DCBlength=sizeof(dcbSerialParams);
	if (!GetCommState(hSerial, &dcbSerialParams)) {
		 cerr << "Couldn't set COM port state" << endl;
	}
	dcbSerialParams.BaudRate=CBR_57600; // Firmware states 57600 baud
	dcbSerialParams.ByteSize=8;
	dcbSerialParams.StopBits=ONESTOPBIT;
	dcbSerialParams.Parity=NOPARITY;
	if(!SetCommState(hSerial, &dcbSerialParams)){
		cerr << "Analyzing error" << endl;
	}

	COMMTIMEOUTS timeouts={0};
	timeouts.ReadIntervalTimeout=50;
	timeouts.ReadTotalTimeoutConstant=50;
	timeouts.ReadTotalTimeoutMultiplier=10;
	timeouts.WriteTotalTimeoutConstant=50;
	timeouts.WriteTotalTimeoutMultiplier=10;
	if(!SetCommTimeouts(hSerial, &timeouts)){
		cerr << "Setting timeout error" << endl;
	}
	return hSerial;
}

void closeSerialPort(HANDLE hSerial) {
	CloseHandle(hSerial);
}

int main() {
	cout << "reading from " << PORTNAME << endl;
	HANDLE handler = initSerial();

	int i = 0;
	while (1) {
                char sync0;
                char sync1;
                struct modeeg_packet msg;

		DWORD dwBytesRead = 0;

                // Find first 0xa5 marker
                do {
			if (!ReadFile(handler, &sync0, 1, &dwBytesRead, NULL)) {
				cerr << "Reading error" << endl;
			}
                } while (sync0 != 0xa5);

		// Read and check second byte for 0x5a
		if (!ReadFile(handler, &sync1, 1, &dwBytesRead, NULL)) {
			cerr << "Reading error" << endl;
		}

		if (sync1 == 0x5a) {
			if (!ReadFile(handler, &msg, n, &dwBytesRead, NULL)) {
				cerr << "Reading error" << endl;
			}

			cout << msg.count << endl;
		}
	}

	closeSerialPort(handler);

	return 0;
}