Pulse Width Modulation

Collaboration diagram for Pulse Width Modulation:

Detailed Description

Allows control of 2 independent PWM channels. A limited subset of GPIO pins can be connected to one of these 2 channels, allowing PWM control of GPIO pins. You have to set the desired pin into a particular Alt Fun to PWM output. See the PWM documentation on the Main Page.

Functions
void	bcm2835_pwm_set_clock (uint32_t divisor)
void	bcm2835_pwm_set_mode (uint8_t channel, uint8_t markspace, uint8_t enabled)
void	bcm2835_pwm_set_range (uint8_t channel, uint32_t range)
void	bcm2835_pwm_set_data (uint8_t channel, uint32_t data)

Function Documentation

void bcm2835_pwm_set_clock

(

uint32_t

divisor

)

Sets the PWM clock divisor, to control the basic PWM pulse widths.

Parameters

[in]

divisor

Divides the basic 19.2MHz PWM clock. You can use one of the common values BCM2835_PWM_CLOCK_DIVIDER_* in bcm2835PWMClockDivider

void bcm2835_pwm_set_data	(	uint8_t	channel,
		uint32_t	data
	)

Sets the PWM pulse ratio to emit to DATA/RANGE, where RANGE is set by bcm2835_pwm_set_range().

Parameters

[in]	channel	The PWM channel. 0 or 1.
[in]	data	Controls the PWM output ratio as a fraction of the range. Can vary from 0 to RANGE.

void bcm2835_pwm_set_mode	(	uint8_t	channel,
		uint8_t	markspace,
		uint8_t	enabled
	)

Sets the mode of the given PWM channel, allowing you to control the PWM mode and enable/disable that channel

Parameters

[in]	channel	The PWM channel. 0 or 1.
[in]	markspace	Set true if you want Mark-Space mode. 0 for Balanced mode.
[in]	enabled	Set true to enable this channel and produce PWM pulses.

void bcm2835_pwm_set_range	(	uint8_t	channel,
		uint32_t	range
	)

Sets the maximum range of the PWM output. The data value can vary between 0 and this range to control PWM output

Parameters

[in]	channel	The PWM channel. 0 or 1.
[in]	range	The maximum value permitted for DATA.