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Fix cadence calculation: use 32-bit delta, correct wrap-around and floating-point division #4905

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Merged
cagnulein merged 3 commits into from
Aug 11, 2026
+64 −21
Merged

Fix cadence calculation: use 32-bit delta, correct wrap-around and floating-point division #4905

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4ffc94e
Fix Stages cadence calculation
cagnulein Aug 10, 2026
c1c2521
Propagate power sensor cadence to CSC bikes
cagnulein Aug 10, 2026
5b3fa40
Parse cycling power cadence in CSC sensors
cagnulein Aug 10, 2026
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78 changes: 60 additions & 18 deletions src/devices/cscbike/cscbike.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -293,14 +293,47 @@ void cscbike::characteristicChanged(const QLowEnergyCharacteristic &characterist
return;
}

if (characteristic.uuid() != QBluetoothUuid((quint16)0x2A5B)) {
bool cyclingPowerMeasurement = characteristic.uuid() == QBluetoothUuid::CyclingPowerMeasurement;
if (characteristic.uuid() != QBluetoothUuid((quint16)0x2A5B) && !cyclingPowerMeasurement) {
return;
}

lastPacket = newValue;

bool CrankPresent = (newValue.at(0) & 0x02) == 0x02;
bool WheelPresent = (newValue.at(0) & 0x01) == 0x01;
bool CrankPresent = false;
bool WheelPresent = false;
if (cyclingPowerMeasurement) {
if (newValue.length() < 4) {
return;
}

uint16_t flags = (((uint16_t)((uint8_t)newValue.at(1)) << 8) | (uint16_t)((uint8_t)newValue.at(0)));
CrankPresent = (flags & 0x20) == 0x20;
if (!CrankPresent) {
return;
}

uint8_t index = 4;
if ((flags & 0x01) == 0x01) {
index += 1; // pedal power balance
}
if ((flags & 0x04) == 0x04) {
index += 2; // accumulated torque
}
if ((flags & 0x10) == 0x10) {
index += 6; // wheel revolutions and wheel event time
}
if (newValue.length() < index + 4) {
return;
}

_CrankRevs = (((uint16_t)((uint8_t)newValue.at(index + 1)) << 8) | (uint16_t)((uint8_t)newValue.at(index)));
_LastCrankEventTime =
(((uint16_t)((uint8_t)newValue.at(index + 3)) << 8) | (uint16_t)((uint8_t)newValue.at(index + 2)));
} else {
CrankPresent = (newValue.at(0) & 0x02) == 0x02;
WheelPresent = (newValue.at(0) & 0x01) == 0x01;
}
qDebug() << QStringLiteral("CrankPresent: ") << CrankPresent;
qDebug() << QStringLiteral("WheelPresent: ") << WheelPresent;

Expand All @@ -318,14 +351,18 @@ void cscbike::characteristicChanged(const QLowEnergyCharacteristic &characterist
emit debug(QStringLiteral("Current Wheel Event Time: ") + QString::number(_LastWheelEventTime));
index += 2;
}
if (CrankPresent) {
if (CrankPresent && !cyclingPowerMeasurement) {
_CrankRevs = (((uint16_t)((uint8_t)newValue.at(index + 1)) << 8) | (uint16_t)((uint8_t)newValue.at(index)));
emit debug(QStringLiteral("Current Crank Revs: ") + QString::number(_CrankRevs));
index += 2;
_LastCrankEventTime =
(((uint16_t)((uint8_t)newValue.at(index + 1)) << 8) | (uint16_t)((uint8_t)newValue.at(index)));
emit debug(QStringLiteral("Current Crank Event Time: ") + QString::number(_LastCrankEventTime));
}
if (cyclingPowerMeasurement) {
emit debug(QStringLiteral("Current Crank Revs: ") + QString::number(_CrankRevs));
emit debug(QStringLiteral("Current Crank Event Time: ") + QString::number(_LastCrankEventTime));
}

// CSC Combo Sensor Fallback Logic
//
Expand All @@ -351,9 +388,9 @@ void cscbike::characteristicChanged(const QLowEnergyCharacteristic &characterist
LastCrankEventTime = _LastCrankEventTime;
}

int16_t deltaT = LastCrankEventTime - oldLastCrankEventTime;
int32_t deltaT = LastCrankEventTime - oldLastCrankEventTime;
if (deltaT < 0) {
deltaT = LastCrankEventTime + 65535 - oldLastCrankEventTime;
deltaT = LastCrankEventTime + 65536 - oldLastCrankEventTime;
}

if (CrankRevs != oldCrankRevs && deltaT) {
Expand Down Expand Up @@ -474,13 +511,14 @@ void cscbike::stateChanged(QLowEnergyService::ServiceState state) {
emit debug(QStringLiteral("BTLE stateChanged ") + QString::fromLocal8Bit(metaEnum.valueToKey(state)));

QBluetoothUuid CyclingSpeedAndCadence(QBluetoothUuid::CyclingSpeedAndCadence);
QBluetoothUuid CyclingPower(QBluetoothUuid::CyclingPower);
QBluetoothUuid Battery(QBluetoothUuid::BatteryService);
for (QLowEnergyService *s : qAsConst(gattCommunicationChannelService)) {
qDebug() << QStringLiteral("stateChanged") << s->serviceUuid() << s->state();
#ifdef Q_OS_WINDOWS
qDebug() << "windows workaround, check only CyclingSpeedAndCadence ftms service"
<< (s->serviceUuid() == CyclingSpeedAndCadence);
if (s->serviceUuid() == CyclingSpeedAndCadence)
qDebug() << "windows workaround, check only cycling sensor services"
<< (s->serviceUuid() == CyclingSpeedAndCadence || s->serviceUuid() == CyclingPower);
if (s->serviceUuid() == CyclingSpeedAndCadence || s->serviceUuid() == CyclingPower)
#endif
{
if (s->state() != QLowEnergyService::ServiceDiscovered && s->state() != QLowEnergyService::InvalidService) {
Expand All @@ -495,13 +533,15 @@ void cscbike::stateChanged(QLowEnergyService::ServiceState state) {
for (QLowEnergyService *s : qAsConst(gattCommunicationChannelService)) {
if (s->state() == QLowEnergyService::ServiceDiscovered) {

if(s->serviceUuid() == CyclingSpeedAndCadence) {
qDebug() << "CyclingSpeedAndCadence found";
if (s->serviceUuid() == CyclingSpeedAndCadence || s->serviceUuid() == CyclingPower) {
qDebug() << "Cycling cadence service found" << s->serviceUuid();
cadenceService = s;
}

if(s->serviceUuid() != CyclingSpeedAndCadence && s->serviceUuid() != Battery) {
// No data from sensors and avatar won’t move in Zwift (even when data showed on first try) (Issue #2178)
if (s->serviceUuid() != CyclingSpeedAndCadence && s->serviceUuid() != CyclingPower &&
s->serviceUuid() != Battery) {
// No data from sensors and avatar won’t move in Zwift (even when data showed on first try) (Issue
// #2178)
qDebug() << "avoid unwaned service";
continue;
}
Expand All @@ -520,8 +560,9 @@ void cscbike::stateChanged(QLowEnergyService::ServiceState state) {

auto characteristics_list = s->characteristics();
for (const QLowEnergyCharacteristic &c : qAsConst(characteristics_list)) {
if(c.uuid() == QBluetoothUuid((quint16)0x2A5B)) {
qDebug() << "CyclingSpeedAndCadence char found";
if (c.uuid() == QBluetoothUuid((quint16)0x2A5B) ||
c.uuid() == QBluetoothUuid::CyclingPowerMeasurement) {
qDebug() << "Cycling cadence characteristic found" << c.uuid();
cadenceChar = c;
}
qDebug() << QStringLiteral("char uuid") << c.uuid() << QStringLiteral("handle") << c.handle() << QStringLiteral("properties") << c.properties();
Expand Down Expand Up @@ -647,9 +688,10 @@ void cscbike::serviceScanDone(void) {
for (const QBluetoothUuid &s : qAsConst(services_list)) {
#ifdef Q_OS_WINDOWS
QBluetoothUuid CyclingSpeedAndCadence(QBluetoothUuid::CyclingSpeedAndCadence);
qDebug() << "windows workaround, check only the CyclingSpeedAndCadence service" << s << CyclingSpeedAndCadence
<< (s == CyclingSpeedAndCadence);
if (s == CyclingSpeedAndCadence)
QBluetoothUuid CyclingPower(QBluetoothUuid::CyclingPower);
qDebug() << "windows workaround, check only cycling sensor services" << s << CyclingSpeedAndCadence
<< CyclingPower << (s == CyclingSpeedAndCadence || s == CyclingPower);
if (s == CyclingSpeedAndCadence || s == CyclingPower)
#endif
{
gattCommunicationChannelService.append(m_control->createServiceObject(s));
Expand Down
7 changes: 4 additions & 3 deletions src/devices/stagesbike/stagesbike.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -311,16 +311,17 @@ void stagesbike::characteristicChanged(const QLowEnergyCharacteristic &character
index += 2;
}

int16_t deltaT = LastCrankEventTime - oldLastCrankEventTime;
int32_t deltaT = LastCrankEventTime - oldLastCrankEventTime;
if (deltaT < 0) {
deltaT = LastCrankEventTime + time_division - oldLastCrankEventTime;
deltaT = LastCrankEventTime + 65536 - oldLastCrankEventTime;
}

if (settings.value(QZSettings::cadence_sensor_name, QZSettings::default_cadence_sensor_name)
.toString()
.startsWith(QStringLiteral("Disabled"))) {
if (CrankRevs != oldCrankRevs && deltaT) {
double cadence = ((CrankRevs - oldCrankRevs) / deltaT) * time_division * 60;
double cadence = (static_cast<double>(CrankRevs - oldCrankRevs) / static_cast<double>(deltaT)) *
time_division * 60.0;
if (!crank_rev_present)
cadence =
cadence /
Expand Down
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