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Fixed and cleaned up the conversion between Dshot and external PWM values.

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This commit is contained in:
Michael Keller 2017-09-21 11:14:21 +12:00 • committed by mikeller
parent b3008b7c8c
commit 8b0d848ce9
1 changed files with 40 additions and 27 deletions
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67
src/main/flight/mixer.c
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@ -104,12 +104,7 @@ void pgResetFn_motorConfig(motorConfig_t *motorConfig)
PG_REGISTER_ARRAY(motorMixer_t, MAX_SUPPORTED_MOTORS, customMotorMixer, PG_MOTOR_MIXER, 0); PG_REGISTER_ARRAY(motorMixer_t, MAX_SUPPORTED_MOTORS, customMotorMixer, PG_MOTOR_MIXER, 0);
#define EXTERNAL_DSHOT_CONVERSION_FACTOR 2 #define PWM_RANGE_MID 1500
// (minimum output value(1001) - (minimum input value(48) / conversion factor(2))
#define EXTERNAL_DSHOT_CONVERSION_OFFSET 977
#define EXTERNAL_CONVERSION_MIN_VALUE 1000
#define EXTERNAL_CONVERSION_MAX_VALUE 2000
#define EXTERNAL_CONVERSION_3D_MID_VALUE 1500
#define TRICOPTER_ERROR_RATE_YAW_SATURATED 75 // rate at which tricopter yaw axis becomes saturated, determined experimentally by TriFlight #define TRICOPTER_ERROR_RATE_YAW_SATURATED 75 // rate at which tricopter yaw axis becomes saturated, determined experimentally by TriFlight
@ -743,44 +738,62 @@ void mixTable(uint8_t vbatPidCompensation)
float convertExternalToMotor(uint16_t externalValue) float convertExternalToMotor(uint16_t externalValue)
{ {
uint16_t motorValue = externalValue; uint16_t motorValue;
switch ((int)isMotorProtocolDshot()) {
#ifdef USE_DSHOT #ifdef USE_DSHOT
if (isMotorProtocolDshot()) { case true:
// Add 1 to the value, otherwise throttle tops out at 2046 externalValue = constrain(externalValue, PWM_RANGE_MIN, PWM_RANGE_MAX);
motorValue = externalValue <= EXTERNAL_CONVERSION_MIN_VALUE ? DSHOT_DISARM_COMMAND : constrain((externalValue - EXTERNAL_DSHOT_CONVERSION_OFFSET) * EXTERNAL_DSHOT_CONVERSION_FACTOR + 1, DSHOT_MIN_THROTTLE, DSHOT_MAX_THROTTLE);
if (feature(FEATURE_3D)) { if (feature(FEATURE_3D)) {
if (externalValue == EXTERNAL_CONVERSION_3D_MID_VALUE) { if (externalValue == PWM_RANGE_MID) {
motorValue = DSHOT_DISARM_COMMAND; motorValue = DSHOT_DISARM_COMMAND;
} else if (motorValue >= DSHOT_MIN_THROTTLE && motorValue <= DSHOT_3D_DEADBAND_LOW) { } else if (externalValue < PWM_RANGE_MID) {
// Add 1 to the value, otherwise throttle tops out at 2046 motorValue = scaleRange(externalValue, PWM_RANGE_MIN, PWM_RANGE_MID - 1, DSHOT_3D_DEADBAND_LOW, DSHOT_MIN_THROTTLE);
motorValue = DSHOT_MIN_THROTTLE + (DSHOT_3D_DEADBAND_LOW - motorValue) + 1; } else {
} motorValue = scaleRange(externalValue, PWM_RANGE_MID + 1, PWM_RANGE_MAX, DSHOT_3D_DEADBAND_HIGH, DSHOT_MAX_THROTTLE);
} }
} else {
motorValue = (externalValue == PWM_RANGE_MIN) ? DSHOT_DISARM_COMMAND : scaleRange(externalValue, PWM_RANGE_MIN + 1, PWM_RANGE_MAX, DSHOT_MIN_THROTTLE, DSHOT_MAX_THROTTLE);
} }
break;
case false:
#endif #endif
default:
motorValue = externalValue;
break;
}
return (float)motorValue; return (float)motorValue;
} }
uint16_t convertMotorToExternal(float motorValue) uint16_t convertMotorToExternal(float motorValue)
{ {
uint16_t externalValue = lrintf(motorValue); uint16_t externalValue;
switch ((int)isMotorProtocolDshot()) {
#ifdef USE_DSHOT #ifdef USE_DSHOT
if (isMotorProtocolDshot()) { case true:
if (feature(FEATURE_3D) && motorValue >= DSHOT_MIN_THROTTLE && motorValue <= DSHOT_3D_DEADBAND_LOW) { if (feature(FEATURE_3D)) {
// Subtract 1 to compensate for imbalance introduced in convertExternalToMotor() if (motorValue == DSHOT_DISARM_COMMAND || motorValue < DSHOT_MIN_THROTTLE) {
motorValue = DSHOT_MIN_THROTTLE + (DSHOT_3D_DEADBAND_LOW - motorValue) - 1; externalValue = PWM_RANGE_MID;
} else if (motorValue <= DSHOT_3D_DEADBAND_LOW) {
externalValue = scaleRange(motorValue, DSHOT_MIN_THROTTLE, DSHOT_3D_DEADBAND_LOW, PWM_RANGE_MID - 1, PWM_RANGE_MIN);
} else {
externalValue = scaleRange(motorValue, DSHOT_3D_DEADBAND_HIGH, DSHOT_MAX_THROTTLE, PWM_RANGE_MID + 1, PWM_RANGE_MAX);
}
} else {
externalValue = (motorValue < DSHOT_MIN_THROTTLE) ? PWM_RANGE_MIN : scaleRange(motorValue, DSHOT_MIN_THROTTLE, DSHOT_MAX_THROTTLE, PWM_RANGE_MIN + 1, PWM_RANGE_MAX);
} }
// Subtract 1 to compensate for imbalance introduced in convertExternalToMotor() break;
externalValue = motorValue < DSHOT_MIN_THROTTLE ? EXTERNAL_CONVERSION_MIN_VALUE : constrain(((motorValue - 1)/ EXTERNAL_DSHOT_CONVERSION_FACTOR) + EXTERNAL_DSHOT_CONVERSION_OFFSET, EXTERNAL_CONVERSION_MIN_VALUE + 1, EXTERNAL_CONVERSION_MAX_VALUE); case false:
if (feature(FEATURE_3D) && motorValue == DSHOT_DISARM_COMMAND) {
externalValue = EXTERNAL_CONVERSION_3D_MID_VALUE;
}
}
#endif #endif
default:
externalValue = motorValue;
break;
}
return externalValue; return externalValue;
} }