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#include "n900accelerometer.h"
#include "../util/util.h"
#include <QFile>
#include <QDebug>
#include <stdio.h>

char const * const n900accelerometer::id("n900.accelerometer");
char const * const n900accelerometer::filename("/sys/class/i2c-adapter/i2c-3/3-001d/coord");
char const * const n900accelerometer::range("/sys/class/i2c-adapter/i2c-3/3-001d/scale");
char const * const n900accelerometer::rate("/sys/class/i2c-adapter/i2c-3/3-001d/rate");

extern bool portraitOrientation;

n900accelerometer::n900accelerometer(QSensor *sensor)
    : n900filebasedsensor(sensor)
{
    setReading<QAccelerometerReading>(&m_reading);
    // According to the kernel driver, this runs at 100 or 400Hz
    // but we can't change the rate because we don't run as root.
    // The hardware seems to run at 100Hz by default so report that.
    // Report 1-100Hz so the app can poll less frequently if it wants to.
    addDataRate(1, 100);
    // According to the kernel driver this reports +- 2G or +- 8G (with lower accuracy)
    // but we can't change the range because we don't run as root.
    // The hardware seems to run at +- 2G by default so report that.
    addOutputRange(-22.418, 22.418, 0.17651); // 2G
    setDescription(QLatin1String("lis302dl"));
}

void n900accelerometer::start()
{
    if (!QFile::exists(QLatin1String(filename)))
        goto error;

    n900filebasedsensor::start();
    return;

error:
    sensorStopped();
}

void n900accelerometer::poll()
{
    // Note that this is a rather inefficient way to generate this data.
    // Ideally the kernel would scale the hardware's values to m/s^2 for us
    // and give us a timestamp along with that data.

    FILE *fd = fopen(filename, "r");
    if (!fd) return;
    int x, y, z;
    int rs = fscanf(fd, "%i %i %i", &x, &y, &z);
    fclose(fd);
    if (rs != 3) return;

    // Convert from milli-Gs to meters per second per second
    // Using 1 G = 9.80665 m/s^2
    qreal ax = x * 0.00980665;
    qreal ay = y * -0.00980665;
    qreal az = z * -0.00980665;

    m_reading.setTimestamp(getTimestamp());
    if (portraitOrientation) {
        m_reading.setX(ay);
        m_reading.setY(-ax);
    } else {
        m_reading.setX(ax);
        m_reading.setY(ay);
    }
    m_reading.setZ(az);

    newReadingAvailable();
}