Zwift + FTMS Server

[MarkusSchneider]

Sequence of FTMS-Server commands send from Zwift in ERG Mode:

1. "Control Request" (0x00)
2. "Reset" (0x01)
3. "Control Request" (0x00)
4. "Start Training" (0x07)
   5 ...) "Set Target Power" (0x05)
5. If you pause Training -> "Set Indoor Bike Simulation Parameter" (0x11) why is Zwift not sending "Stop or Pause" (0x08) ??
6. If you resume Training -> "Set Target Power" (0x05)
7. If workout is finished -> "Set Indoor Bike Simulation Parameter" (0x11)

Sequence of FTMS-Server commands send from Zwift in Sim Mode:

1. "Control Request" (0x00)
2. "Reset" (0x01)
3. "Control Request" (0x00)
4. "Start Training" (0x07)
   5..) "Set Indoor Bike Simulation Parameter" (0x11)

Even if Game is ended Zwift does not send "Stop or Pause"

[doudar]

It is a bit weird but I’m guessing it’s because Zwift is otherwise always in Sim mode.

You’re right, we should implement stop though.

[MarkusSchneider]

Create a new Branch and added Stop and Cadence Control Point.
Is WIP, not sure if everything is korrekt.
See

SmartSpin2k/src/BLE_Server.cpp

Lines 72 to 79 in 2d3b3db

	struct FitnessMachineFeature ftmsFeature = {
	FitnessMachineFeatureFlags::Types::CadenceSupported | FitnessMachineFeatureFlags::Types::HeartRateMeasurementSupported |
	FitnessMachineFeatureFlags::Types::PowerMeasurementSupported | FitnessMachineFeatureFlags::Types::InclinationSupported |
	FitnessMachineFeatureFlags::Types::ResistanceLevelSupported,
	FitnessMachineTargetFlags::PowerTargetSettingSupported | FitnessMachineTargetFlags::Types::InclinationTargetSettingSupported |
	FitnessMachineTargetFlags::Types::ResistanceTargetSettingSupported | FitnessMachineTargetFlags::Types::IndoorBikeSimulationParametersSupported |
	FitnessMachineTargetFlags::Types::SpinDownControlSupported | FitnessMachineTargetFlags::Types::TargetedCadenceConfigurationSupported};

and

SmartSpin2k/src/BLE_Server.cpp

Lines 422 to 433 in 2d3b3db

	case 0x08: // Stop or Pause
	returnValue[2] = FitnessMachineControlPointResultCode::Success; // 0x01;
	pCharacteristic->setValue(returnValue, 3);
	// rxValue[1] == 1 -> Stop, 2 -> Pause
	// TODO: Move stepper to Min Position
	logBufLength += snprintf(logBuf + logBufLength, kLogBufCapacity - logBufLength, "-> Stop Training");
	ftmsTrainingStatus[1] = FitnessMachineTrainingStatus::Other; // 0x00;
	fitnessMachineTrainingStatus->setValue(ftmsTrainingStatus, 2);
	fitnessMachineTrainingStatus->notify();
	break;

and

SmartSpin2k/src/BLE_Server.cpp

Lines 467 to 481 in 2d3b3db

	case 0x15: { // Set Targeted Cadence
	returnValue[2] = FitnessMachineControlPointResultCode::Success; // 0x01;
	pCharacteristic->setValue(returnValue, 3);
	int targetCadence = bytes_to_u16(rxValue[2], rxValue[1]);
	// rtConfig.setTargetWatts(targetWatts);
	logBufLength += snprintf(logBuf + logBufLength, kLogBufCapacity - logBufLength, "-> Target Cadence: %d ", targetCadence);
	uint8_t ERGStatus[3] = {0x08, (uint8_t)rxValue[1], 0x01};
	fitnessMachineStatusCharacteristic->setValue(ERGStatus, 3);
	ftmsTrainingStatus[1] = FitnessMachineTrainingStatus::Other; // 0x00;
	fitnessMachineTrainingStatus->setValue(ftmsTrainingStatus, 2);
	fitnessMachineTrainingStatus->notify();
	} break;

Don't know if line 475 is correct.
For what is the fitnessMachineStatusCharacteristic used? I can not find a description of this value in the FTMS specification.

[doudar]

It's on 4.17 (page66) and you'll see an example in Appendix 3 on the FTMS document for the spin down procedure.

Then there's "training status" on page 46.

It's a very confusing document

[doudar]

And it looks like training status could use some (re)work for each mode (case) as well.

I The first byte gets initialized to 0x08 on line 85 (which I don't think is correct) and never gets changed. 0x08 means "fitness test" if it was in byte 1 but nothing in byte 0.

Edit: I see some of those case statements are correct. We just need to change the initialization to 0x00, 0x00

[doudar]

I just noticed another small thing that should be fixed.

SmartSpin2k/src/BLE_Server.cpp

Line 83 in ceefb34

uint8_t ftmsPowerRange[6] = {0x00, 0x01, 0xA0, 0x0F, 0x01, 0x00}; // 1:4000 watts increment 1

Shouldn't be hardcoded and should instead reference:

SmartSpin2k/include/settings.h

Line 82 in ceefb34

#define MIN_WATTS 50

and

SmartSpin2k/include/SmartSpin_parameters.h

Line 130 in ceefb34

int getMaxWatts() { return maxWatts; }

[MarkusSchneider]

According FitnessMachineTrainingStatus. Since SS2k is not controlling the training it's maybe not necessary to notify training status.
See FTMS Chapter 4.10.1

[doudar]

Maybe you should use it for the btsimulator.html 😝

[MarkusSchneider]

uint8_t cadenceStatus[3] = {0x15, (uint8_t)rxValue[2], (uint8_t)rxValue[1]};
fitnessMachineStatusCharacteristic->setValue(ERGStatus, 3);

Should be correct, needs to be fixed for power value as well.

See FTMS Chapter 4.17Fitness Machine Status

OpCode -> 0x15: Target Cadence Changed
Parameter -> Target Cadence as read from Client