A pulse-width modulation digital output. More...

#include <PwmOut.h>

Public Member Functions
	PwmOut (PinName pin)
	Create a PwmOut connected to the specified pin. More...

	PwmOut (const PinMap &pinmap)
	Create a PwmOut connected to the specified pin. More...

void	write (float value)
	Set the output duty-cycle, specified as a percentage (float) More...

float	read ()
	Return the current output duty-cycle setting, measured as a percentage (float) More...

void	period (float seconds)
	Set the PWM period, specified in seconds (float), keeping the duty cycle the same. More...

void	period_ms (int ms)
	Set the PWM period, specified in milliseconds (int), keeping the duty cycle the same. More...

void	period_us (int us)
	Set the PWM period, specified in microseconds (int), keeping the duty cycle the same. More...

int	read_period_us ()
	Read the PWM period. More...

void	pulsewidth (float seconds)
	Set the PWM pulsewidth, specified in seconds (float), keeping the period the same. More...

void	pulsewidth_ms (int ms)
	Set the PWM pulsewidth, specified in milliseconds (int), keeping the period the same. More...

void	pulsewidth_us (int us)
	Set the PWM pulsewidth, specified in microseconds (int), keeping the period the same. More...

int	read_pulsewitdth_us ()
	Read the PWM pulsewidth. More...

void	suspend ()
	Suspend PWM operation. More...

void	resume ()
	Resume PWM operation. More...

PwmOut &	operator= (float value)
	A operator shorthand for write() More...

PwmOut &	operator= (PwmOut &rhs)
	A operator shorthand for write() More...

	operator float ()
	An operator shorthand for read() More...

Detailed Description

A pulse-width modulation digital output.

Note: Synchronization level: Interrupt safe

Example

// Gradually change the intensity of the LED.
#include "mbed.h"
PwmOut led(LED1);
int main() {
    while(1) {
        led = led + 0.01;
        ThisThread::sleep_for(200);
        if(led == 1.0) {
            led = 0;
        }
    }
}

Definition at line 54 of file PwmOut.h.

Constructor & Destructor Documentation

PwmOut ( PinName pin )

Create a PwmOut connected to the specified pin.

Parameters

pin	PwmOut pin to connect to

PwmOut ( const PinMap & pinmap )

Create a PwmOut connected to the specified pin.

Parameters

pinmap reference to structure which holds static pinmap.

Member Function Documentation

operator float ( )

An operator shorthand for read()

See also: PwmOut::read()

Definition at line 181 of file PwmOut.h.

PwmOut& operator= ( float value )

A operator shorthand for write()

See also: PwmOut::write()

Definition at line 161 of file PwmOut.h.

PwmOut& operator= ( PwmOut & rhs )

A operator shorthand for write()

See also: PwmOut::write()

Definition at line 171 of file PwmOut.h.

void period ( float seconds )

Set the PWM period, specified in seconds (float), keeping the duty cycle the same.

Parameters

seconds Change the period of a PWM signal in seconds (float) without modifying the duty cycle

Note: The resolution is currently in microseconds; periods smaller than this will be set to zero.

void period_ms ( int ms )

Set the PWM period, specified in milliseconds (int), keeping the duty cycle the same.

Parameters

ms	Change the period of a PWM signal in milliseconds without modifying the duty cycle

void period_us ( int us )

Set the PWM period, specified in microseconds (int), keeping the duty cycle the same.

Parameters

us	Change the period of a PWM signal in microseconds without modifying the duty cycle

void pulsewidth ( float seconds )

Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.

Parameters

seconds Change the pulse width of a PWM signal specified in seconds (float)

void pulsewidth_ms ( int ms )

Set the PWM pulsewidth, specified in milliseconds (int), keeping the period the same.

Parameters

ms	Change the pulse width of a PWM signal specified in milliseconds

void pulsewidth_us ( int us )

Set the PWM pulsewidth, specified in microseconds (int), keeping the period the same.

Parameters

us	Change the pulse width of a PWM signal specified in microseconds

float read ( )

Return the current output duty-cycle setting, measured as a percentage (float)

Returns: A floating-point value representing the current duty-cycle being output on the pin, measured as a percentage. The returned value will lie between 0.0f (representing on 0%) and 1.0f (representing on 100%).

Note: This value may not match exactly the value set by a previous write().

int read_period_us ( )

Read the PWM period.

Returns: The PWM period, specified in microseconds (int)

int read_pulsewitdth_us ( )

Read the PWM pulsewidth.

Returns: The PWM pulsewith, specified in microseconds (int)

void resume ( )

Resume PWM operation.

Control the PWM state. This is primarily intended to resume PWM operations after a previous PwmOut::suspend call; This call restores the device state prior to suspension.

void suspend ( )

Suspend PWM operation.

Control the PWM state. This is primarily intended for temporary power-saving; This call can allow pwm to be temporarily disabled to permit power saving without losing device state. The subsequent function call must be PwmOut::resume for PWM to resume; any other calls prior to resuming are undefined behavior.

void write ( float value )

Set the output duty-cycle, specified as a percentage (float)

Parameters

value A floating-point value representing the output duty-cycle, specified as a percentage. The value should lie between 0.0f (representing on 0%) and 1.0f (representing on 100%). Values outside this range will be saturated to 0.0f or 1.0f.

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

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