Counter Functions

Functions
HAL_CounterHandle	HAL_InitializeCounter (int channel, HAL_Bool risingEdge, const char *allocationLocation, int32_t *status)
	Initializes a counter.
void	HAL_FreeCounter (HAL_CounterHandle counterHandle)
	Frees a counter.
void	HAL_SetCounterEdgeConfiguration (HAL_CounterHandle counterHandle, HAL_Bool risingEdge, int32_t *status)
	Sets the up source to either detect rising edges or falling edges.
void	HAL_ResetCounter (HAL_CounterHandle counterHandle, int32_t *status)
	Resets the Counter to zero.
int32_t	HAL_GetCounter (HAL_CounterHandle counterHandle, int32_t *status)
	Reads the current counter value.
double	HAL_GetCounterPeriod (HAL_CounterHandle counterHandle, int32_t *status)
	Gets the Period of the most recent count.
void	HAL_SetCounterMaxPeriod (HAL_CounterHandle counterHandle, double maxPeriod, int32_t *status)
	Sets the maximum period where the device is still considered "moving".
HAL_Bool	HAL_GetCounterStopped (HAL_CounterHandle counterHandle, int32_t *status)
	Determines if the clock is stopped.

Detailed Description

Function Documentation

HAL_FreeCounter()

void HAL_FreeCounter

(

HAL_CounterHandle

counterHandle

)

Frees a counter.

Parameters

[in]

counterHandle

the counter handle

HAL_GetCounter()

int32_t HAL_GetCounter	(	HAL_CounterHandle	counterHandle,
		int32_t *	status )

Reads the current counter value.

Reads the value at this instant. It may still be running, so it reflects the current value. Next time it is read, it might have a different value.

Parameters

[in]	counterHandle	the counter handle
[out]	status	Error status variable. 0 on success.

Returns

the current counter value

HAL_GetCounterPeriod()

double HAL_GetCounterPeriod	(	HAL_CounterHandle	counterHandle,
		int32_t *	status )

Gets the Period of the most recent count.

Returns the time interval of the most recent count. This can be used for velocity calculations to determine shaft speed.

Parameters

[in]	counterHandle	the counter handle
[out]	status	Error status variable. 0 on success.

Returns

the period of the last two pulses in units of seconds

HAL_GetCounterStopped()

HAL_Bool HAL_GetCounterStopped	(	HAL_CounterHandle	counterHandle,
		int32_t *	status )

Determines if the clock is stopped.

Determine if the clocked input is stopped based on the MaxPeriod value set using the SetMaxPeriod method. If the clock exceeds the MaxPeriod, then the device (and counter) are assumed to be stopped and it returns true.

Parameters

[in]	counterHandle	the counter handle
[out]	status	Error status variable. 0 on success.

Returns

true if the most recent counter period exceeds the MaxPeriod value set by SetMaxPeriod

HAL_InitializeCounter()

HAL_CounterHandle HAL_InitializeCounter	(	int	channel,
		HAL_Bool	risingEdge,
		const char *	allocationLocation,
		int32_t *	status )

Initializes a counter.

Parameters

[in]	channel	the dio channel
[in]	risingEdge	true to count on rising edge, false for falling
[in]	allocationLocation	the location where the allocation is occurring (can be null)
[out]	status	Error status variable. 0 on success.

Returns

the created handle

HAL_ResetCounter()

void HAL_ResetCounter	(	HAL_CounterHandle	counterHandle,
		int32_t *	status )

Resets the Counter to zero.

Sets the counter value to zero. This does not effect the running state of the counter, just sets the current value to zero.

Parameters

[in]	counterHandle	the counter handle
[out]	status	Error status variable. 0 on success.

HAL_SetCounterEdgeConfiguration()

void HAL_SetCounterEdgeConfiguration	(	HAL_CounterHandle	counterHandle,
		HAL_Bool	risingEdge,
		int32_t *	status )

Sets the up source to either detect rising edges or falling edges.

Note that both are allowed to be set true at the same time without issues.

Parameters

[in]	counterHandle	the counter handle
[in]	risingEdge	true to trigger on rising
[out]	status	Error status variable. 0 on success.

HAL_SetCounterMaxPeriod()

void HAL_SetCounterMaxPeriod	(	HAL_CounterHandle	counterHandle,
		double	maxPeriod,
		int32_t *	status )

Sets the maximum period where the device is still considered "moving".

Sets the maximum period where the device is considered moving. This value is used to determine the "stopped" state of the counter using the HAL_GetCounterStopped method.

Parameters

[in]	counterHandle	the counter handle
[in]	maxPeriod	the maximum period where the counted device is considered moving in seconds
[out]	status	Error status variable. 0 on success.