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/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Motion sensor calibration code. */
#include "accelerometer.h"
#include "common.h"
#include "console.h"
#include "math_util.h"
#include "motion_sense.h"
#include "timer.h"
#include "task.h"
#include "util.h"
/*
* Threshold to capture a sample when performing auto-calibrate. The units are
* the same as the units of the accelerometer acceleration values.
*/
#define AUTO_CAL_DIR_THRESHOLD (ACCEL_G * 3 / 4)
#define AUTO_CAL_MAG_THRESHOLD (ACCEL_G / 20)
/*****************************************************************************/
/* Console commands */
/**
* Print all orientation calibration data.
*/
static int command_print_orientation(int argc, char **argv)
{
matrix_3x3_t (*R);
R = &acc_orient.rot_align;
ccprintf("Lid to base alignment R:\n%.2d\t%.2d\t%.2d\n%.2d\t%.2d\t%.2d"
"\n%.2d\t%.2d\t%.2d\n\n",
(int)((*R)[0][0]*100), (int)((*R)[0][1]*100), (int)((*R)[0][2]*100),
(int)((*R)[1][0]*100), (int)((*R)[1][1]*100), (int)((*R)[1][2]*100),
(int)((*R)[2][0]*100), (int)((*R)[2][1]*100), (int)((*R)[2][2]*100));
R = &acc_orient.rot_hinge_90;
ccprintf("Hinge rotation 90 R:\n%.2d\t%.2d\t%.2d\n%.2d\t%.2d\t%.2d\n"
"%.2d\t%.2d\t%.2d\n\n",
(int)((*R)[0][0]*100), (int)((*R)[0][1]*100), (int)((*R)[0][2]*100),
(int)((*R)[1][0]*100), (int)((*R)[1][1]*100), (int)((*R)[1][2]*100),
(int)((*R)[2][0]*100), (int)((*R)[2][1]*100), (int)((*R)[2][2]*100));
R = &acc_orient.rot_hinge_180;
ccprintf("Hinge rotation 180 R:\n%.2d\t%.2d\t%.2d\n%.2d\t%.2d\t%.2d\n"
"%.2d\t%.2d\t%.2d\n\n",
(int)((*R)[0][0]*100), (int)((*R)[0][1]*100), (int)((*R)[0][2]*100),
(int)((*R)[1][0]*100), (int)((*R)[1][1]*100), (int)((*R)[1][2]*100),
(int)((*R)[2][0]*100), (int)((*R)[2][1]*100), (int)((*R)[2][2]*100));
ccprintf("Hinge Axis:\t%d\t%d\t%d\n", acc_orient.hinge_axis[0],
acc_orient.hinge_axis[1],
acc_orient.hinge_axis[2]);
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(accelorient, command_print_orientation,
"",
"Print all orientation calibration data", NULL);
/**
* Calibrate the orientation and print results to console.
*
* @param type 0 is for calibrating lid to base alignment,
* 1 is for calibrating hinge 90 rotation
*/
static int calibrate_orientation(int type)
{
int mag, ret, i, j;
/* Captured flags. Set true when the corresponding axis is captured. */
int captured[3] = {0, 0, 0};
/* Current acceleration vectors. */
vector_3_t base, lid;
static matrix_3x3_t rec_base, rec_lid;
while (1) {
/* Capture the current acceleration vectors. */
motion_get_accel_lid(&lid, type);
motion_get_accel_base(&base);
/* Measure magnitude of base accelerometer. */
mag = vector_magnitude(base);
/*
* Only capture a sample if the magnitude of the acceleration
* is close to G, because this assures we won't calibrate with
* values biased by motion.
*/
if ((mag > ACCEL_G - AUTO_CAL_MAG_THRESHOLD) &&
(mag < ACCEL_G + AUTO_CAL_MAG_THRESHOLD)) {
/*
* Capture a sample when each axis exceeds some
* threshold. This guarantees linear independence.
*/
for (i = 0; i < 3; i++) {
if (!captured[i] &&
ABS(base[i]) > AUTO_CAL_DIR_THRESHOLD) {
for (j = 0; j < 3; j++) {
rec_base[i][j] = (float)base[j];
rec_lid[i][j] = (float)lid[j];
}
ccprintf("Captured axis %d\n", i);
captured[i] = 1;
}
}
/* If all axes are captured, we are done. */
if (captured[0] && captured[1] && captured[2])
break;
}
/* Wait until next reading. */
task_wait_event(50*MSEC);
}
/* Solve for the rotation matrix and display final rotation matrix. */
if (type == 0)
ret = solve_rotation_matrix(&rec_lid, &rec_base,
&acc_orient.rot_align);
else
ret = solve_rotation_matrix(&rec_base, &rec_lid,
&acc_orient.rot_hinge_90);
if (ret != EC_SUCCESS)
ccprintf("Failed to find rotation matrix.\n");
return ret;
}
/**
* Calibrate the hinge axis and hinge 180 rotation matrix.
*/
static int calibrate_hinge(void)
{
static matrix_3x3_t tmp;
float d;
int i, j;
vector_3_t base;
motion_get_accel_base(&base);
memcpy(&acc_orient.hinge_axis, &base, sizeof(vector_3_t));
/*
* Calculate a rotation matrix to rotate 180 degrees about hinge axis.
* The formula is:
*
* rot_hinge_180 = I + 2 * tmp^2 / d^2,
* where tmp is a matrix formed from the hinge axis, d is the sqrt
* of the hinge axis vector used in tmp, and I is the 3x3 identity
* matrix.
*
*/
tmp[0][0] = 0;
tmp[0][1] = base[2];
tmp[0][2] = -base[1];
tmp[1][0] = -base[2];
tmp[1][1] = 0;
tmp[1][2] = base[0];
tmp[2][0] = base[1];
tmp[2][1] = -base[0];
tmp[2][2] = 0;
matrix_multiply(&tmp, &tmp, &acc_orient.rot_hinge_180);
d = (float)(SQ(base[0]) + SQ(base[1]) + SQ(base[2]));
for (i = 0; i < 3; i++) {
for (j = 0; j < 3; j++) {
acc_orient.rot_hinge_180[i][j] *= 2.0F / d;
/* Add identity matrix. */
if (i == j)
acc_orient.rot_hinge_180[i][j] += 1;
}
}
return EC_SUCCESS;
}
static int command_auto_calibrate(int argc, char **argv)
{
char *e;
int type, ret;
static int last_type = -1;
if (argc != 2)
return EC_ERROR_PARAM_COUNT;
type = strtoi(argv[1], &e, 0);
if (*e)
return EC_ERROR_PARAM1;
/*
* First time this issued, just display instructions and return. If
* command is repeated, then perform calibration.
*/
if (type != last_type) {
/*
* type 0: calibrate the lid to base alignment rotation matrix.
* type 1: calibrate the hinge 90 rotation matrix.
* type 2: calibrate hinge axis and hinge 180 rotation matrix.
*/
switch (type) {
case 0:
ccprintf("To calibrate, close lid, issue this command "
"again, and rotate the machine in space until "
"all 3 directions are captured.\n");
break;
case 1:
ccprintf("To calibrate, open lid to 90 degrees, issue "
" this command again, and rotate in space "
"until all 3 directions are captured.\n");
break;
case 2:
ccprintf("To calibrate, align hinge with gravity, and "
"issue this command again.\n");
break;
default:
return EC_ERROR_PARAM1;
}
last_type = type;
return EC_SUCCESS;
}
/* Call appropriate calibration function. */
if (type == 0 || type == 1)
ret = calibrate_orientation(type);
else
ret = calibrate_hinge();
/* Print results of all calibration. */
if (ret == EC_SUCCESS)
command_print_orientation(0, NULL);
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(accelcalib, command_auto_calibrate,
"0 - Calibrate lid to base alignment rotation matrix\n1 - Calibrate "
"hinge positive 90 rotation matrix\n2 - Calibrate hinge axis and hinge "
"180 matrix",
"Auto calibrate the accelerometers", NULL);
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