Use case: encoder mode

Sequence diagram

LPTIM encoder mode

  @startuml
  title: LPTIM Encoder mode

  participant "User Application" as appli
  participant "<font color=green><b>HAL LPTIM</b></font>" as LPTIM

  group#Bisque #Linen LPTIM operation

  == Prerequisite: initialization and configuration  ==
  appli->LPTIM: HAL_LPTIM_Init();\n
  LPTIM-->appli: <color #Green> HAL_OK

  == Process ==
  appli->LPTIM : HAL_LPTIM_Encoder_Start()\n
  LPTIM-->appli : <color #Green> HAL_OK
  appli->LPTIM : HAL_LPTIM_ReadCounter()
  appli->LPTIM : HAL_LPTIM_Encoder_Stop()
  LPTIM-->appli : <color #Green> HAL_OK

  == LPTIM Deinitialization ==
  appli->LPTIM : <b>HAL_LPTIM_DeInit</b>()
  LPTIM-->appli : <color #Green> HAL_OK
  end

  @enduml

Code snippet

HAL1

HAL2

LPTIM_HandleTypeDef             LptimHandle;

LptimHandle.Instance = LPTIM1;
LptimHandle.Init.CounterSource                 = LPTIM_COUNTERSOURCE_INTERNAL;
LptimHandle.Init.UpdateMode                    = LPTIM_UPDATE_IMMEDIATE;
LptimHandle.Init.OutputPolarity                = LPTIM_OUTPUTPOLARITY_HIGH;
LptimHandle.Init.Clock.Source                  = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
LptimHandle.Init.Clock.Prescaler               = LPTIM_PRESCALER_DIV1;
LptimHandle.Init.UltraLowPowerClock.Polarity   = LPTIM_CLOCKPOLARITY_RISING;
LptimHandle.Init.UltraLowPowerClock.SampleTime = LPTIM_CLOCKSAMPLETIME_DIRECTTRANSITION;
LptimHandle.Init.Trigger.Source                = LPTIM_TRIGSOURCE_SOFTWARE;
LptimHandle.Init.Trigger.ActiveEdge            = LPTIM_ACTIVEEDGE_RISING ;
LptimHandle.Init.Trigger.SampleTime            = LPTIM_TRIGSAMPLETIME_DIRECTTRANSITION;
LptimHandle.Init.Input1Source                  = LPTIM_INPUT1SOURCE_GPIO;
LptimHandle.Init.Input2Source                  = LPTIM_INPUT2SOURCE_GPIO;

/* Initialize and configure the LPTIM Instance */
HAL_LPTIM_Init(&LptimHandle);


/* Start LPTIM Encoder mode */
HAL_LPTIM_Encoder_Start(&LptimHandle, 5000);


/* Read the counter value */
uint32_t encoder_count = HAL_LPTIM_ReadCounter(&LptimHandle);

/* Stop Encoder mode when done and deinitialize the LPTIM instance */
HAL_LPTIM_Encoder_Stop(&LptimHandle)
HAL_LPTIM_DeInit(&LPTIM_Handle);
hal_lptim_handle_t LPTIM_Handle;
hal_lptim_config_t p_config;
hal_lptim_encoder_config_t p_encoder;

p_config.mode = HAL_LPTIM_CONTINUOUS;
p_config.prescaler = HAL_LPTIM_CLK_SRC_DIV1;
p_config.repetition_counter = 0;
p_config.period = 5000;
p_config.clock_source = HAL_LPTIM_CLK_ENCODER_SUBMODE_1;

/*Set the Encoder Configuration */
p_encoder.input1 = HAL_LPTIM_INPUT1_GPIO;
p_encoder.input2 = HAL_LPTIM_INPUT2_GPIO;
p_encoder.filter = HAL_LPTIM_FDIV1;


/* Initialize and configure the LPTIM Instance */
HAL_LPTIM_Init(&LPTIM_Handle, HAL_LPTIM1);
HAL_LPTIM_SetConfig(&LPTIM_Handle, &p_config);

/* Start LPTIM Encoder mode */
HAL_LPTIM_SetConfigEncoder(&LPTIM_Handle, &p_encoder);
HAL_LPTIM_Start(&LPTIM_Handle);

/* Read the counter value */
uint32_t encoder_count = HAL_LPTIM_GetCounter(&LPTIM_Handle);

/* Stop Encoder mode when done and deinitialize the LPTIM instance */
HAL_LPTIM_Stop(&LPTIM_Handle);
HAL_LPTIM_DeInit(&LPTIM_Handle);

Key changes

  1. HAL2 splits configuration from initialization using HAL_LPTIM_SetConfig().

  2. HAL2 configures encoder mode explicitly using HAL_LPTIM_SetConfigEncoder().

  3. HAL2 uses HAL_LPTIM_GetCounter() instead of HAL_LPTIM_ReadCounter().