Configuration

The settings a TMC9660 needs before it drives a motor, in the order to apply them, with the struct for each.

Most subsystems have a configureAuto(Config) call: required fields first, optional fields with defaults, values written in a safe order and verified. Use it for bring-up; the individual setters stay available for tuning. Every snippet here is compiled from tests/docs/configuration.cpp.

Order

Step	Call	Why this position
1	bootloaderInit(&cfg)	Clock, interfaces and feedback pins are bootloader settings (Bootloader)
2	gateDriver.configurePowerStageProtection(PowerStageProfile)	Timing and protection of the power stage, before any PWM
3	currentSensing.configureAuto(...), calibrateOffsets()	Offsets are measured with the motor off
4	motorConfig.configureAuto(MotorProfile)	Motor type, pole pairs, PWM, current limits
5	feedbackSense.configureAuto(HallConfig / AbnConfig / SpiEncoderConfig)	The sensor the loops will use
6	torqueFluxControl, velocityControl, positionControl .configureAuto(...)	Loop gains and scaling
7	protection	Voltage, temperature and current thresholds
8	motorConfig.setCommutationMode(...)	Last: the chip starts driving as soon as it is set

Current sensing

Driver::CurrentSensing::AutoConfig cs{};
cs.shuntResistance_mOhm = 3.0f;     // from the schematic
cs.expectedPeakCurrent_A = 6.0f;    // picks the amplifier gain
if (!driver.currentSensing.configureAuto(cs) ||
    !driver.currentSensing.calibrateOffsets(true, 2000)) {  // motor off, wait up to 2 s
  return false;
}

Field	Required	Meaning
shuntResistance_mOhm	yes	Nominal shunt value
expectedPeakCurrent_A	yes	Highest phase current you expect; sets the amplifier gain
usePeakScaling		Scale for peak rather than RMS current
actualShuntR_adc0_mOhm ... adc3		Measured shunt values per channel, if they differ from nominal

Motor

The API guide shows MotorProfile in context.

Field	Required	Default	Meaning
motorType	yes		BLDC_MOTOR, STEPPER_MOTOR or DC_MOTOR
polePairs	yes		BLDC: rotor pole pairs. Stepper: full steps per revolution / 4
pwmFrequency_Hz	yes		20 to 25 kHz is typical
maxPhaseCurrent_A	yes		Sets MAX_TORQUE and MAX_FLUX
direction		FORWARD	Swap to reverse without rewiring
pwmSwitchingScheme		SVPWM	Space-vector PWM for BLDC
maxFluxCurrent_A		20 % of the phase current	Flux limit
outputVoltageLimit		8000	FOC output voltage limit (internal units)
idlePwmBehavior		PWM off when idle
commutationMode		unchanged	Applied last, if set

Control loops

Driver::TorqueFluxControl::TorqueFluxConfig tf{};
tf.torqueP = 50;                    // unset gains keep the driver's defaults (50 / 100)
tf.torqueI = 100;
if (!driver.torqueFluxControl.configureAuto(tf)) {
  return false;
}

Driver::VelocityControl::VelocityConfig vel{};
vel.sensorSelection = tmcl::VelocitySensorSelection::DIGITAL_HALL;
vel.velocityP = 800;
vel.velocityI = 1;
if (!driver.velocityControl.configureAuto(vel)) {
  return false;
}

Gains are the chip's integer PI parameters. Start with the defaults, raise P until the response is fast without overshoot, then raise I to remove the steady-state error. Tune torque first, then velocity, then position.

Struct	Required	Notable optional fields
TorqueFluxConfig		torqueP, torqueI, separateTorqueFluxLoops, enableFieldWeakening
VelocityConfig	sensorSelection	velocityP, velocityI, pNormalization, iNormalization, scaling
PositionConfig	sensorSelection	positionP, positionI, normalisation

Protection

driver.protection.configureVoltage(/*over*/ 300, /*under*/ 100);  // 0.1 V units: 30.0 V, 10.0 V
driver.protection.configureTemperature(100.0f, 120.0f);          // warning, shutdown in degrees C
driver.protection.setOvercurrentEnabled(true);

The voltage thresholds are in 0.1 V. Set them around your supply's real range: a 24 V system might warn at 30 V and 18 V. protection.configureAuto(ProtectionConfig) sets all of them at once.

Where the defaults come from

Each field's default is in its struct in inc/tmc9660.hpp and in the API reference; the chip's own reset values are in the parameter-mode reference.