Files
GoldenCheetah/src/PowerTapUtil.cpp
Sean Rhea 6e56b8652f rename PowerTap.(h|cpp) to PowerTapUtil.(h|cpp)
...in preparation for separating out a PowerTapDevice class.
2009-08-09 15:33:02 -07:00

426 lines
12 KiB
C++

/*
* Copyright (c) 2008 Sean C. Rhea (srhea@srhea.net)
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "PowerTapUtil.h"
#include <math.h>
#define PT_DEBUG false
static bool
hasNewline(const char *buf, int len)
{
static char newline[] = { 0x0d, 0x0a };
if (len < 2)
return false;
for (int i = 0; i < len; ++i) {
bool success = true;
for (int j = 0; j < 2; ++j) {
if (buf[i+j] != newline[j]) {
success = false;
break;
}
}
if (success)
return true;
}
return false;
}
static QString
cEscape(const char *buf, int len)
{
char *result = new char[4 * len + 1];
char *tmp = result;
for (int i = 0; i < len; ++i) {
if (buf[i] == '"')
tmp += sprintf(tmp, "\\\"");
else if (isprint(buf[i]))
*(tmp++) = buf[i];
else
tmp += sprintf(tmp, "\\x%02x", 0xff & (unsigned) buf[i]);
}
return result;
}
static bool
doWrite(CommPortPtr dev, char c, bool hwecho, QString &err)
{
if (PT_DEBUG) printf("writing '%c' to device\n", c);
int n = dev->write(&c, 1, err);
if (n != 1) {
if (n < 0)
err = QString("failed to write %1 to device: %2").arg(c).arg(err);
else
err = QString("timeout writing %1 to device").arg(c);
return false;
}
if (hwecho) {
char c;
int n = dev->read(&c, 1, err);
if (n != 1) {
if (n < 0)
err = QString("failed to read back hardware echo: %2").arg(err);
else
err = "timeout reading back hardware echo";
return false;
}
}
return true;
}
static int
readUntilNewline(CommPortPtr dev, char *buf, int len, QString &err)
{
int sofar = 0;
while (!hasNewline(buf, sofar)) {
assert(sofar < len);
// Read one byte at a time to avoid waiting for timeout.
int n = dev->read(buf + sofar, 1, err);
if (n <= 0) {
err = (n < 0) ? ("read error: " + err) : "read timeout";
err += QString(", read %1 bytes so far: \"%2\"")
.arg(sofar).arg(cEscape(buf, sofar));
return -1;
}
sofar += n;
}
return sofar;
}
bool
PowerTap::download(CommPortPtr dev, QByteArray &version,
QVector<unsigned char> &records,
StatusCallback statusCallback, QString &err)
{
if (!dev->open(err)) {
err = "ERROR: open failed: " + err;
return false;
}
if (!doWrite(dev, 0x56, false, err)) // 'V'
return false;
if (!statusCallback(STATE_READING_VERSION)) {
err = "download cancelled";
return false;
}
char vbuf[256];
int version_len = readUntilNewline(dev, vbuf, sizeof(vbuf), err);
if (version_len < 0) {
err = "Error reading version: " + err;
return false;
}
if (PT_DEBUG) {
printf("read version \"%s\"\n",
cEscape(vbuf, version_len).toAscii().constData());
}
version = QByteArray(vbuf, version_len);
// We expect the version string to be something like
// "VER 02.21 PRO...", so if we see two V's, it's probably
// because there's a hardware echo going on.
int veridx = version.indexOf("VER");
if (veridx < 0) {
err = QString("Unrecognized version \"%1\"")
.arg(cEscape(vbuf, version_len));
return false;
}
bool hwecho = version.indexOf('V') < veridx;
if (PT_DEBUG) printf("hwecho=%s\n", hwecho ? "true" : "false");
if (!statusCallback(STATE_READING_HEADER)) {
err = "download cancelled";
return false;
}
if (!doWrite(dev, 0x44, hwecho, err)) // 'D'
return false;
unsigned char header[6];
int header_len = dev->read(header, sizeof(header), err);
if (header_len != 6) {
if (header_len < 0)
err = "ERROR: reading header: " + err;
else
err = "ERROR: timeout reading header";
return false;
}
if (PT_DEBUG) {
printf("read header \"%s\"\n",
cEscape((char*) header,
sizeof(header)).toAscii().constData());
}
for (size_t i = 0; i < sizeof(header); ++i)
records.append(header[i]);
if (!statusCallback(STATE_READING_DATA)) {
err = "download cancelled";
return false;
}
fflush(stdout);
while (true) {
if (PT_DEBUG) printf("reading block\n");
unsigned char buf[256 * 6 + 1];
int n = dev->read(buf, 2, err);
if (n < 2) {
if (n < 0)
err = "ERROR: reading first two: " + err;
else
err = "ERROR: timeout reading first two";
return false;
}
if (PT_DEBUG) {
printf("read 2 bytes: \"%s\"\n",
cEscape((char*) buf, 2).toAscii().constData());
}
if (hasNewline((char*) buf, 2))
break;
unsigned count = 2;
while (count < sizeof(buf)) {
n = dev->read(buf + count, sizeof(buf) - count, err);
if (n < 0) {
err = "ERROR: reading block: " + err;
return false;
}
if (n == 0) {
err = "ERROR: timeout reading block";
return false;
}
if (PT_DEBUG) {
printf("read %d bytes: \"%s\"\n", n,
cEscape((char*) buf + count, n).toAscii().constData());
}
count += n;
}
unsigned csum = 0;
for (int i = 0; i < ((int) sizeof(buf)) - 1; ++i)
csum += buf[i];
if ((csum % 256) != buf[sizeof(buf) - 1]) {
err = "ERROR: bad checksum";
return false;
}
if (PT_DEBUG) printf("good checksum\n");
for (size_t i = 0; i < sizeof(buf) - 1; ++i)
records.append(buf[i]);
if (!statusCallback(STATE_DATA_AVAILABLE)) {
err = "download cancelled";
return false;
}
if (!doWrite(dev, 0x71, hwecho, err)) // 'q'
return false;
}
return true;
}
bool
PowerTap::is_ignore_record(unsigned char *buf, bool bVer81)
{
if (bVer81)
return buf[0]==0 && buf[1]==0 && buf[2]==0;
else
return buf[0]==0;
}
bool
PowerTap::is_Ver81(unsigned char *buf)
{
return buf[3] == 0x81;
}
int
PowerTap::is_time(unsigned char *buf, bool bVer81)
{
return (bVer81 && buf[0] == 0x10) || (!bVer81 && buf[0] == 0x60);
}
time_t
PowerTap::unpack_time(unsigned char *buf, struct tm *time, bool bVer81)
{
(void) bVer81; // unused
memset(time, 0, sizeof(*time));
time->tm_year = 2000 + buf[1] - 1900;
time->tm_mon = buf[2] - 1;
time->tm_mday = buf[3] & 0x1f;
time->tm_hour = buf[4] & 0x1f;
time->tm_min = buf[5] & 0x3f;
time->tm_sec = ((buf[3] >> 5) << 3) | (buf[4] >> 5);
time->tm_isdst = -1;
return mktime(time);
}
int
PowerTap::is_config(unsigned char *buf, bool bVer81)
{
return (bVer81 && buf[0] == 0x00) || (!bVer81 && buf[0] == 0x40);
}
const double TIME_UNIT_SEC = 0.021*60.0;
const double TIME_UNIT_SEC_V81 = 0.01;
int
PowerTap::unpack_config(unsigned char *buf, unsigned *interval,
unsigned *last_interval, double *rec_int_secs,
unsigned *wheel_sz_mm, bool bVer81)
{
*wheel_sz_mm = (buf[1] << 8) | buf[2];
/* Data from device wraps interval after 9... */
if (buf[3] != *last_interval) {
*last_interval = buf[3];
++*interval;
}
*rec_int_secs = buf[4];
if (bVer81)
{
*rec_int_secs *= TIME_UNIT_SEC_V81;
}
else
{
*rec_int_secs += 1;
*rec_int_secs *= TIME_UNIT_SEC;
}
return 0;
}
int
PowerTap::is_data(unsigned char *buf, bool bVer81)
{
if (bVer81)
return (buf[0] & 0x40) == 0x40;
else
return (buf[0] & 0x80) == 0x80;
}
static double
my_round(double x)
{
int i = (int) x;
double z = x - i;
/* For some unknown reason, the PowerTap software rounds 196.5 down... */
if ((z > 0.5) || ((z == 0.5) && (i != 196)))
++i;
return i;
}
#define MAGIC_CONSTANT 147375.0
#define PI M_PI
#define LBFIN_TO_NM 0.11298483
#define KM_TO_MI 0.62137119
#define BAD_LBFIN_TO_NM_1 0.112984
#define BAD_LBFIN_TO_NM_2 0.1129824
#define BAD_KM_TO_MI 0.62
void
PowerTap::unpack_data(unsigned char *buf, int compat, double rec_int_secs,
unsigned wheel_sz_mm, double *time_secs,
double *torque_Nm, double *mph, double *watts,
double *dist_m, unsigned *cad, unsigned *hr, bool bVer81)
{
if (bVer81)
{
const double CLOCK_TICK_TIME = 0.000512;
const double METERS_PER_SEC_TO_MPH = 2.23693629;
*time_secs += rec_int_secs;
int rotations = buf[0] & 0x0f;
int ticks_for_1_rotation = (buf[1]<<4) | (buf[2]>>4);
if (ticks_for_1_rotation==0xff0 || ticks_for_1_rotation==0)
{
*watts = 0;
*cad = 0;
*mph = 0;
*torque_Nm = 0;
}
else
{
*watts = ((buf[2] & 0x0f) << 8) | buf[3];
*cad = buf[4];
if (*cad == 0xff)
*cad = 0;
double wheel_sz_meters = wheel_sz_mm / 1000.0;
*dist_m += rotations * wheel_sz_meters;
double seconds_for_1_rotation = ticks_for_1_rotation * CLOCK_TICK_TIME;
double meters_per_sec = wheel_sz_meters / seconds_for_1_rotation;
*mph = meters_per_sec * METERS_PER_SEC_TO_MPH;
*torque_Nm = (*watts * seconds_for_1_rotation)/(2.0*PI);
}
*hr = buf[5];
if (*hr == 0xff)
*hr = 0;
}
else
{
double kph10;
unsigned speed;
unsigned torque_inlbs;
*time_secs += rec_int_secs;
torque_inlbs = ((buf[1] & 0xf0) << 4) | buf[2];
if (torque_inlbs == 0xfff)
torque_inlbs = 0;
speed = ((buf[1] & 0x0f) << 8) | buf[3];
if ((speed < 100) || (speed == 0xfff)) {
if ((speed != 0) && (speed < 1000)) {
fprintf(stderr, "possible error: speed=%.1f; ignoring it\n",
MAGIC_CONSTANT / speed / 10.0);
}
*mph = -1.0;
*watts = -1.0;
}
else {
if (compat)
*torque_Nm = torque_inlbs * BAD_LBFIN_TO_NM_2;
else
*torque_Nm = torque_inlbs * LBFIN_TO_NM;
kph10 = MAGIC_CONSTANT / speed;
if (compat)
*mph = my_round(kph10) / 10.0 * BAD_KM_TO_MI;
else
*mph = kph10 / 10.0 * KM_TO_MI;
// from http://en.wikipedia.org/wiki/Torque#Conversion_to_other_units
double dMetersPerMinute = (kph10 / 10.0) * 1000.0 / 60.0;
double dWheelSizeMeters = wheel_sz_mm / 1000.0;
double rpm = dMetersPerMinute/dWheelSizeMeters;
*watts = *torque_Nm * rpm * 2.0 * PI /60.0;
if (compat)
*watts = my_round(*watts);
else
*watts = round(*watts);
}
if (compat)
*torque_Nm = torque_inlbs * BAD_LBFIN_TO_NM_1;
*dist_m += (buf[0] & 0x7f) * wheel_sz_mm / 1000.0;
*cad = buf[4];
if (*cad == 0xff)
*cad = 0;
*hr = buf[5];
if (*hr == 0xff)
*hr = 0;
}
}