gistfile1.cpp

// hubsan x4 tx frame decoder
// input: data.txt = saleae logic spi decoder exported output.
// output: dataout.txt = transmission data frames

#include <QtCore/QCoreApplication>
#include <qfile.h>
#include <qstringlist.h>
/*
Ex1: 20 00 00 00 80 00 7d 00 84 02 64 db 04 26 79 7b
Ex2: 20 00 00 00 80 00 7d 00 84 02 64 db 04 26 79 7b
     aa bb cc dd ee ff gg hh ii jj kk ll mm nn oo pp
cc : throttle observed range: 0x00 - 0xff (smaller is down)
ee : rudder observed range: 0x34 - 0xcc (smaller is right)
gg : elevator observed range: 0x3e - 0xbc (smaller is up)
ii : aileron observed range: 0x45 - 0xc3 (smaller is right)
llmmnnoo: Transmiter ID(?)
pp : checksum
Checksums:
The checksum is calculated as 256 - ((sum of the 1st 15 bytes) modulo 256)
*/

QString toHex(const char byte)
{
	QString hex;
	if( byte<16) hex = "0";
	hex += QString::number(byte,16);
	return hex;
}

int main(int argc, char *argv[])
{
	// 1st phase, convert text output to data binary file
	QFile in("E:\\Users\\goebish\\Desktop\\data.txt");
	QFile::remove("E:\\Users\\goebish\\Desktop\\data.bin");
	QFile out("E:\\Users\\goebish\\Desktop\\data.bin");

	in.open(QIODevice::ReadOnly);
	out.open(QIODevice::WriteOnly);
	QString line = in.readLine(); // skip first line
	while(!in.atEnd())
	{
		line = in.readLine();
		QString data = line.split("0x")[1].left(2);
		bool ok;
		unsigned char byte = data.toInt(&ok,16);
		out.write((const char*)&byte,1);
	}
	out.close();
	in.close();

	// 2nd phase, detect data transmission packets and dump them to text file
	out.open(QIODevice::ReadOnly);
	QByteArray buffer = out.readAll();
	out.close();
	QFile::remove("E:\\Users\\goebish\\Desktop\\dataout.txt");
	QFile out2("E:\\Users\\goebish\\Desktop\\dataout.txt");
	out2.open(QIODevice::WriteOnly);
	int pos=0;
	
	int line_size = 21; // 16
	int offset = 0;


	while(pos<buffer.size()-line_size)
	{
		
		/*if(pos%16==0) out2.write("\n    ");
			unsigned char data = buffer.at(pos);
			QString hex = QString::number(data,16)+' ';
			if(data < 16)
				out2.write("0");
			out2.write(hex.toAscii());*/
		
		if( buffer.at(pos)   == (char)0x05 // start of TX packet ? 
			/*||
			buffer.at(pos)   == (char)0x42  // start of RX packet ? */
		)
		{
			if(buffer.at(pos) == (char)0x05) // A0
			{
				offset = 1;
				//out2.write( toHex(buffer.at(pos+1)).toAscii()+' ');
				//out2.write( toHex(buffer.at(pos+2)).toAscii()+' ');
				//out2.write( toHex(buffer.at(pos+3)).toAscii()+'\n');
				out2.write("\nTx: ");
			}
			/*else if(buffer.at(pos) == (char)0x42) // 18
			{
				offset = 1;
				out2.write( toHex(buffer.at(pos+1)).toAscii()+' ');
				out2.write( toHex(buffer.at(pos+2)).toAscii()+'\n');
				out2.write("\nRx: ");
			}*/
			int pos2 = pos+offset; // start of data;
			int dumped=0;
			while(pos2 < buffer.size() && dumped < line_size)
			{
				unsigned char data = buffer.at(pos2);
				QString hex = QString::number(data,16)+' ';
				if(data < 16)
					out2.write("0");
				out2.write(hex.toUpper().toAscii());
				pos2++;
				dumped++;
				pos=pos2;
			}
		}
		
		pos++;
	}
	out2.close();
}