PWM_IC.h File Reference

PWM Input Capture handling. More...

#include "sarmfsw.h"

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Data Structures
struct	PWM_IC
	PWM input capture structure. More...

Functions
GPIO_PinState	PWM_IC_get_Pin_State_Callback (const uint8_t idx)
	PWM Input Capture get Pin state (in case of timeout, or at startup)
FctERR	init_PWM_IC (PWM_IC *const pPWM_IC, TIM_HandleTypeDef *const pTim, const uint32_t Direct_Channel, const uint32_t Indirect_Channel, const uint32_t Scale)
	Init PWM Input Capture channel.
uint32_t	get_PWM_IC_Freq (PWM_IC *const pPWM_IC)
	Get current PWM Input Capture frequency.
uint32_t	get_PWM_IC_DutyCycle (PWM_IC *const pPWM_IC)
	Get current PWM Input Capture duty cycle.
void	PWM_IC_handler (void)
	PWM Input Capture handler.

Variables
PWM_IC	PWMin [1]

Detailed Description

PWM Input Capture handling.

Author

SMFSW

Copyright

MIT (c) 2017-2026, SMFSW

PWM_IC input configuration: TIM with multiple channels with slave mode capability shall be used

Slave Mode: Reset Mode Trigger: TI1FP1/TI2FP2 (depending physical MCU pin used tied to channel 1 or 2) Channel tied to pin: Input Capture direct mode Channel (2nd one): Input Capture indirect mode

Prescaler & CLK div: 0, No CLK div Counter Period: max possible value Counter Mode: Up Auto-Reload Preload: Disabled Trigger Output parameters: Disabled Input Capture Channel tied to pin: Rising Edge, Direct, No CLK div Input Capture Channel (2nd one): Falling Edge, Indirect, No CLK div

Instead, CubeMX Combined channels capture may be configured to PWM input capture, avoiding manual timer configuration

GPIO configuration: Alternate Function Push Pull ; Pull Up (if needed) ; High Speed may be recommended

NVIC configuration: Enable interrupt(s) if PWM_IC_NO_IT is not defined at project level

Note

Define NB_PWM_IC symbol with number of inputs at project level to use PWM_IC functionalities

Define PWM_IC_NO_IT symbol at project level to disable TIM interrupts driven capture

Warning

Input Capture limitation:

• Lower/Higher frequency/duty cycle measurable totally depends on TIM configuration and clocks used.
• Continuous signal (pin held low or high) is detected automatically after timeout:
  • automatically when using interrupts driven PWM input capture
  • by calling PWM_IC_get_Pin_State_Callback without interrupts
• !!Please note there can be up to 1 second with startup timeout during which low to high continuous signal may be misinterpreted before retrieving values!!
• If PWM signal to capture can never become continuous, it may save some time of servicing interrupts to disable them (with PWM_IC_NO_IT symbol)

Function Documentation

get_PWM_IC_DutyCycle()

uint32_t get_PWM_IC_DutyCycle

(

PWM_IC *const

pPWM_IC

)

Get current PWM Input Capture duty cycle.

Parameters

[in]

pPWM_IC

- pointer to PWM_IC instance

Returns

Measured duty cycle

get_PWM_IC_Freq()

uint32_t get_PWM_IC_Freq

(

PWM_IC *const

pPWM_IC

)

Get current PWM Input Capture frequency.

Parameters

[in]

pPWM_IC

- pointer to PWM_IC instance

Returns

Measured frequency

init_PWM_IC()

FctERR init_PWM_IC	(	PWM_IC *const	pPWM_IC,
		TIM_HandleTypeDef *const	pTim,
		const uint32_t	Direct_Channel,
		const uint32_t	Indirect_Channel,
		const uint32_t	Scale )

Init PWM Input Capture channel.

Parameters

[in,out]	pPWM_IC	- pointer to PWM input capture instance
[in,out]	pTim	- pointer to TIM instance
[in]	Direct_Channel	- Direct Channel used for PWM input capture
[in]	Indirect_Channel	- Indirect Channel used for PWM input capture
[in]	Scale	- PWM input capture duty cycle output scale

Returns

FctERR - Error code

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PWM_IC_get_Pin_State_Callback()

GPIO_PinState PWM_IC_get_Pin_State_Callback

(

const uint8_t

idx

)

PWM Input Capture get Pin state (in case of timeout, or at startup)

Weak Functions

Function declared as weak, needs to be customly implemented in user code, otherwise returns RESET state

Parameters

[in]

idx

- PWM_IC instance index

Returns

Pin state

GPIO_TypeDef *  GPIOx;
uint16_t        GPIO_Pin;
 
... Set proper GPIOx and GPIO_Pin according to PWMin idx
 
return HAL_GPIO_ReadPin(GPIOx, GPIO_Pin);

PWM_IC_handler()

void PWM_IC_handler

(

void

)

PWM Input Capture handler.

Note

Shall to be called periodically if PWM_IC_NO_IT is defined

When interrupts are used, handler can be called periodically (but not required), results getters will perform the conversion when required

Variable Documentation

PWMin

PWM_IC PWMin[1]

extern