Blower Class Reference

Controls a blower. More...

#include <blower.h>

Public Member Functions
	Blower ()
	Default constructor. More...
	Blower (HardwareTimer *p_hardwareTimer, uint16_t p_timerChannel, uint16_t p_blowerPin)
	Parameterized constructor. More...
void	setup ()
	Initialize the hardware timer used to control the blower. More...
void	runSpeedWithRampUp (uint16_t p_targetSpeed)
	Run the blower to a given speed applying a ramp-up to prevent high current drain. More...
void	runSpeed (uint16_t p_runSpeed)
	Run the blower to a given speed. More...
void	execute ()
void	stop ()
	Stops the blower. More...
uint16_t	getSpeed () const
	Get speed value. More...
uint16_t	getTargetSpeed () const
	Get target speed value. More...
int32_t	getBlowerPressure (int32_t p_flow)
	Given a flow in mL/min, return an estimated pressure just at the output of the blower. More...

Private Attributes
HardwareTimer *	actuator
	Hardware timer used to control the blower. More...
uint16_t	timerChannel
	Channel of the hardware timer used to control the blower. More...
uint16_t	blowerPin
	Pin of the blower. More...
uint16_t	m_speed
	Current speed. More...
uint16_t	m_targetSpeed
	target speed More...
bool	m_stopped
	Current state. More...
uint32_t	m_lastCallDate

Detailed Description

Controls a blower.

Definition at line 27 of file blower.h.

Constructor & Destructor Documentation

Blower() [1/2]

Blower::Blower

(

)

Default constructor.

Definition at line 24 of file blower.cpp.

{}

Blower() [2/2]

Blower::Blower	(	HardwareTimer *	p_hardwareTimer,
		uint16_t	p_timerChannel,
		uint16_t	p_blowerPin
	)

Parameterized constructor.

Parameters

p_hardwareTimer	Hardware time for the blower
p_timerChannel	TIM channel for this blower
p_blowerPin	Data pin for this blower

Definition at line 26 of file blower.cpp.

                                                                                            {
    actuator = p_hardwareTimer;
    timerChannel = p_timerChannel;
    blowerPin = p_blowerPin;
    m_stopped = true;
    m_speed = 0;
    m_targetSpeed = 0;
    m_lastCallDate = millis();
}

Member Function Documentation

execute()

void Blower::execute

(

)

Definition at line 55 of file blower.cpp.

                     {
    // apply ramp-up
    // Max acceleration is one unit per ms. This means full ramp-up in 1.8s
    uint32_t currentDate = micros();
    uint16_t runSpeed = 0;
    if (m_targetSpeed > m_speed) {
        runSpeed = min(m_targetSpeed, uint16_t(m_speed + (currentDate - m_lastCallDate) / 1000u));
    } else {
        runSpeed = m_targetSpeed;
    }
    m_lastCallDate = currentDate;
    this->runSpeed(runSpeed);
}

getBlowerPressure()

int32_t Blower::getBlowerPressure

(

int32_t

p_flow

)

Given a flow in mL/min, return an estimated pressure just at the output of the blower.

This pressure has been determined using the pressure-flow characteristic of the blower

Parameters

p_flow

inspiratory flow in mL/min

Definition at line 85 of file blower.cpp.

                                                {
    int32_t returnValue;
    // For now the blower has only been characterize at max speed
    if (m_speed == MAX_BLOWER_SPEED) {
        // This order 2 characteruzation has been made experimentally
        returnValue =
            703 - (281 * (p_flow / 100000)) - 832 * (p_flow / 200) * (p_flow / 500) / 100000;
    } else {
        // todo better characterization
        returnValue = 703 * static_cast<int32_t>(m_speed) / static_cast<int32_t>(MAX_BLOWER_SPEED)
                      - (281 * (p_flow / 100000)) - 832 * (p_flow / 200) * (p_flow / 500) / 100000;
    }
 
    return min(int32_t(703), max(returnValue, int32_t(0)));
}

getSpeed()

uint16_t Blower::getSpeed

(

)

const

Get speed value.

Definition at line 101 of file blower.cpp.

{ return m_speed; }

getTargetSpeed()

uint16_t Blower::getTargetSpeed

(

)

const

Get target speed value.

Definition at line 103 of file blower.cpp.

{ return m_targetSpeed; }

runSpeed()

void Blower::runSpeed

(

uint16_t

p_runSpeed

)

Run the blower to a given speed.

Parameters

p_runSpeed

Speed between MIN_BLOWER_SPEED and MAX_BLOWER_SPEED

Definition at line 69 of file blower.cpp.

                                         {
    // cppcheck-suppress unsignedPositive ; MIN_BLOWER_SPEED might not be equal to 0
    if ((p_runSpeed >= MIN_BLOWER_SPEED) && (p_runSpeed <= MAX_BLOWER_SPEED)) {
        // do not forcefully set the capture compare again and again if speed do not change
        if (m_stopped || (m_speed != p_runSpeed)) {
            actuator->setCaptureCompare(timerChannel, BlowerSpeed2MicroSeconds(p_runSpeed),
                                        MICROSEC_COMPARE_FORMAT);
            m_speed = p_runSpeed;
            m_stopped = false;
        }
    } else {
        DBG_DO(Serial.print("Blower value is wrong: "));
        DBG_DO(Serial.println(p_runSpeed));
    }
}

runSpeedWithRampUp()

void Blower::runSpeedWithRampUp

(

uint16_t

p_targetSpeed

)

Run the blower to a given speed applying a ramp-up to prevent high current drain.

Parameters

p_targetSpeed

Speed between MIN_BLOWER_SPEED and MAX_BLOWER_SPEED

Definition at line 44 of file blower.cpp.

                                                      {
    // cppcheck-suppress unsignedPositive ; MIN_BLOWER_SPEED might not be equal to 0
    if ((p_targetSpeed >= MIN_BLOWER_SPEED) && (p_targetSpeed <= MAX_BLOWER_SPEED)) {
        if (p_targetSpeed != m_targetSpeed) {  // first time with new target
            m_lastCallDate = micros();
            m_targetSpeed = p_targetSpeed;
            m_speed = max(m_speed, uint16_t(MIN_BLOWER_SPEED));
        }
    }
}

setup()

void Blower::setup

(

)

Initialize the hardware timer used to control the blower.

Definition at line 36 of file blower.cpp.

                   {
    actuator->setMode(timerChannel, TIMER_OUTPUT_COMPARE_PWM1, blowerPin);
 
    // Set PPM width to 1ms
    actuator->setCaptureCompare(timerChannel, BlowerSpeed2MicroSeconds(0), MICROSEC_COMPARE_FORMAT);
    actuator->resume();
}

stop()

void Blower::stop

(

)

Stops the blower.

Definition at line 105 of file blower.cpp.

                  {
    actuator->setCaptureCompare(timerChannel, BlowerSpeed2MicroSeconds(0), MICROSEC_COMPARE_FORMAT);
    m_stopped = true;
    m_speed = 0;
    m_targetSpeed = 0;
}

Member Data Documentation

actuator

HardwareTimer* Blower::actuator

private

Hardware timer used to control the blower.

Definition at line 78 of file blower.h.

blowerPin

uint16_t Blower::blowerPin

private

Pin of the blower.

Definition at line 84 of file blower.h.

m_lastCallDate

uint32_t Blower::m_lastCallDate

private

Definition at line 96 of file blower.h.

m_speed

uint16_t Blower::m_speed

private

Current speed.

Definition at line 87 of file blower.h.

m_stopped

bool Blower::m_stopped

private

Current state.

Definition at line 93 of file blower.h.

m_targetSpeed

uint16_t Blower::m_targetSpeed

private

target speed

Definition at line 90 of file blower.h.

timerChannel

uint16_t Blower::timerChannel

private

Channel of the hardware timer used to control the blower.

Definition at line 81 of file blower.h.

---

The documentation for this class was generated from the following files:

• includes/blower.h
• srcs/blower.cpp