accelerometer.cc

#include <fstream>
#include <iostream>
#include <unistd.h>
#include <math.h>
#include <sstream>

using namespace std;

struct XYZAxisStruct{
	int xAxis;
	int yAxis;
	int zAxis;
};

enum screenOrientation{normal, inverted, leftUp, rightUp, initialState};

void handleOrientation(XYZAxisStruct, bool, screenOrientation*);
void readAxis(bool, screenOrientation*);
int runCommand(string);

int runCommand(string command){
	FILE* pipe = popen(command.c_str(), "r");
	if(pipe)
		return 0;
	else{
		cerr << "Couldn't run command : \"" << command << "\"" << endl;
		return -1;
	}
}

void readAxis(bool verbose, screenOrientation* orientation){
	string xValue, yValue, zValue;
	XYZAxisStruct XYZAxis;

	ifstream xAxisPath ("/sys/bus/iio/devices/iio:device0/in_accel_x_raw");
	ifstream yAxisPath ("/sys/bus/iio/devices/iio:device0/in_accel_y_raw");
	ifstream zAxisPath ("/sys/bus/iio/devices/iio:device0/in_accel_z_raw");

  	
  	if(xAxisPath.is_open() && yAxisPath.is_open() && zAxisPath.is_open()){
    	while(getline(xAxisPath,xValue) && getline(yAxisPath, yValue) && getline(zAxisPath, zValue)){
      		if(verbose)
      		cout << "Raw X Value: " << xValue << " | Raw Y Value: " << yValue << " | Raw Z Value: " << zValue << endl;
      		stringstream(xValue) >> XYZAxis.xAxis;
      		stringstream(yValue) >> XYZAxis.yAxis;
      		stringstream(zValue) >> XYZAxis.zAxis;
      		XYZAxis.xAxis*=0.000598;
      		XYZAxis.yAxis*=0.000598; 
      		XYZAxis.zAxis*=0.000598;  
      		handleOrientation(XYZAxis, verbose, orientation);
    	}
  	}
  	else{
  		cerr << "Couldn't open device paths" << endl;
  	}
}

void handleOrientation(XYZAxisStruct XYZAxis, bool verbose, screenOrientation* orientation){
	string xrandrRotationCmd[4] = {"xrandr --orientation normal",
								"xrandr --orientation inverted",
								"xrandr --orientation left",
								"xrandr --orientation right"};

	string xinputRotationCmd[4] = {"xinput set-prop 'ATML1000:00 03EB:8C42' 'Coordinate Transformation Matrix' 1 0 0 0 1 0 0 0 1",
								   "xinput set-prop 'ATML1000:00 03EB:8C42' 'Coordinate Transformation Matrix' -1 0 1 0 -1 1 0 0 1",
								   "xinput set-prop 'ATML1000:00 03EB:8C42' 'Coordinate Transformation Matrix' 0 -1 1 1 0 0 0 0 1",
									"xinput set-prop 'ATML1000:00 03EB:8C42' 'Coordinate Transformation Matrix'  0 1 0 -1 0 1 0 0 1"};

	const char* startOnboardCmd = "onboard";
	const char* terminateOnboardCmd = "killall onboard >/dev/null 2>&1";

	if(verbose){
		cout << "X Axis g (approx.): " << XYZAxis.xAxis << endl;
		cout << "Y Axis g (approx.): " << XYZAxis.yAxis << endl;
		cout << "Z Axis g (approx.): " << XYZAxis.zAxis << endl;
		cout << "----------" << endl;
	}

	if(7 < abs(XYZAxis.xAxis) && 11 > abs(XYZAxis.xAxis) && XYZAxis.xAxis > 0 && *orientation != normal){
		if(verbose) cout << "Orientation is normal" << endl;
		*orientation = normal;
		runCommand(xrandrRotationCmd[0]);
		runCommand(terminateOnboardCmd);
		runCommand(xinputRotationCmd[0]);
	}else if(7 < abs(XYZAxis.xAxis) && 11 > abs(XYZAxis.xAxis) && XYZAxis.zAxis < -2 && *orientation != inverted){
		if(verbose) cout << "Orientation is inverted" << endl;
		*orientation = inverted;
		runCommand(xrandrRotationCmd[1]);
		runCommand(startOnboardCmd);
		runCommand(xinputRotationCmd[1]);
	}else if(-7 >= XYZAxis.yAxis && -11 <= XYZAxis.yAxis && *orientation != leftUp){
		if(verbose) cout << "Orientation is left up" << endl;
		*orientation = leftUp;
		runCommand(xrandrRotationCmd[2]);
		runCommand(startOnboardCmd);
		runCommand(xinputRotationCmd[2]);	
	}else if(11 > XYZAxis.yAxis && 7 < XYZAxis.yAxis && XYZAxis.xAxis == 0 && *orientation != rightUp){
		if(verbose) cout << "Orientation is rightUp" << endl;
		*orientation = rightUp;
		runCommand(xrandrRotationCmd[3]);
		runCommand(startOnboardCmd);
		runCommand(xinputRotationCmd[3]);
	}
	
}

int main(int argc, char* argv[]){
	bool verbose = false;
	screenOrientation orientation = initialState;
	
	if(argc > 1 && (string(argv[1]) == "-v" || string(argv[1]) == "--verbose"))
		verbose = true;
		
	cout << "Listening for orientation change..." << endl;
	while(true){
		readAxis(verbose, &orientation);
		usleep(100);
	}
	return 0;
}