Data Structures
struct	_ENC_Obj_
	Defines the encoder object. More...

Macros
#define	ENC_SPEED_SCALING_FACTOR 16777216.0

#define	ENC_ZERO_OFFSET 3813071.0

#define	ENC_SPEED_CUTOFF_FREQ 100.0

#define	ENC_SPEED_COEFF_Q 6

#define	ENC_SPEED_COEFF_SCALING (1<<ENC_SPEED_COEFF_Q)

#define	ENC_2PI (2.0*3.14159)

#define	ENC_LOG_LEN 256

#define	ENC_RPM_Q1 8

#define	ENC_RPM_Q2 16

#define	ENC_LOG_DELTA_TRIGGER_THRES 400

Typedefs
typedef struct _ENC_Obj_	ENC_Obj
	Defines the encoder object. More...

typedef struct _ENC_Obj_ *	ENC_Handle
	Defines the encoder handle. More...

Enumerations
enum	ENC_LOG_State_e { ENC_LOG_STATE_IDLE =0, ENC_LOG_STATE_FREERUN, ENC_LOG_STATE_ACQUIRE }
	Enumeration for the encoder log states. More...

Functions
void	ENC_calcElecAngle (ENC_Handle encHandle, uint32_t posnCounts)
	Reads encoder and returns the electrical degrees in Q24 format. More...

_iq	ENC_getElecAngle (ENC_Handle encHandle)
	Returns the electrical angle. More...

_iq	ENC_getMagneticAngle (ENC_Handle encHandle)
	Returns the magnetic angle. More...

_iq	ENC_getFilteredSpeed (ENC_Handle encHandle)
	Returns the low-pass filtered speed output. More...

int16_t	ENC_getSpeedRPM (ENC_Handle encHandle)
	Returns the filtered speed in RPM. More...

ENC_Handle	ENC_init (void *pMemory, const size_t numBytes)
	Initializes the encoder object. More...

void	ENC_run (ENC_Handle encHandle, uint32_t posnCounts, uint16_t indextFlag, uint16_t dirFlag, int16_t log_flag)
	Based on the encoder reading, computes the electrical angle and the electrical "speed". More...

void	ENC_setIncrementalSlip (ENC_Handle encHandle, _iq incrementalSlip)
	Set the amount of incremental slip. More...

void	ENC_setRunFlag (ENC_Handle encHandle)
	Start logging encoder data. More...

void	ENC_setZeroOffset (ENC_Handle encHandle, uint32_t zeroOffset)
	Sets the value for the encoder object zero offset. More...

void	ENC_setup (ENC_Handle encHandle, const int16_t sample_period, const uint16_t num_pole_pairs, const uint16_t num_enc_slots, const uint32_t enc_zero_offset, const float_t full_scale_freq, const float_t speed_update_freq, const float_t speed_cutoff)
	Initializes encoder object parameters. More...

Detailed Description

Data Structure Documentation

struct _ENC_Obj_

Defines the encoder object.

Definition at line 86 of file enc.h.

Data Fields
int32_t	delta_enc	encoder count delta
int32_t	enc_elec_angle	encoder current electrical angle
int32_t	enc_magnetic_angle	encoder current magnetic angle (compensated for slip)
int32_t	enc_slip_angle	amount of total slip
uint32_t	enc_zero_offset	encoder zero offset in counts
float_t	full_scale_freq	full scale frequency
int32_t	incremental_slip	incremental amount of slip
int16_t	log[ENC_LOG_LEN]	encoder log length
int32_t	log_idx	encoder log index
ENC_LOG_State_e	log_state	encoder log state
_iq	mech_angle_gain	gain which converts the encoder counts to Q24 mechanical degrees
uint16_t	num_enc_slots	number of encoder slots
uint16_t	num_pole_pairs	number of pole pairs in motor
int16_t	post_trigger_cnt	encoder log post trigger counter
int16_t	post_trigger_len	encoder log post trigger length
int32_t	prev_enc	previous encoder reading
int32_t	rpm_gain	gain which converts the Q24 normalized electrical freq to RPM
int16_t	run_flag	encoder log free run flag
int16_t	sample_count	when it reaches the sample period, collect & process encoder data
int16_t	sample_period	sample period of encoder processing
float_t	speed_cutoff	speed cutoff frequency in Hz
int32_t	speed_gain	gain which converts a difference in encoder counts to Q24 normalized electrical freq
int32_t	speed_lpf_cx	speed input coefficient
int32_t	speed_lpf_cy	speed output coefficient
int32_t	speed_lpf_out	speed lpf output
int16_t	trigger_delta	calculated delta when trigger happened
int16_t	trigger_idx	index where trigger event happened

Macro Definition Documentation

#define ENC_2PI (2.0*3.14159)

Definition at line 65 of file enc.h.

Referenced by ENC_setup().

#define ENC_LOG_DELTA_TRIGGER_THRES 400

Definition at line 69 of file enc.h.

Referenced by ENC_run().

#define ENC_LOG_LEN 256

Definition at line 66 of file enc.h.

Referenced by ENC_run(), and ENC_setup().

#define ENC_RPM_Q1 8

Definition at line 67 of file enc.h.

Referenced by ENC_getSpeedRPM().

#define ENC_RPM_Q2 16

Definition at line 68 of file enc.h.

Referenced by ENC_getSpeedRPM().

#define ENC_SPEED_COEFF_Q 6

Definition at line 63 of file enc.h.

Referenced by ENC_run().

#define ENC_SPEED_COEFF_SCALING (1<<ENC_SPEED_COEFF_Q)

Definition at line 64 of file enc.h.

Referenced by ENC_setup().

#define ENC_SPEED_CUTOFF_FREQ 100.0

Definition at line 62 of file enc.h.

#define ENC_SPEED_SCALING_FACTOR 16777216.0

Definition at line 60 of file enc.h.

Referenced by ENC_setup().

#define ENC_ZERO_OFFSET 3813071.0

Definition at line 61 of file enc.h.

Typedef Documentation

typedef struct _ENC_Obj_* ENC_Handle

Defines the encoder handle.

Definition at line 120 of file enc.h.

typedef struct _ENC_Obj_ ENC_Obj

Defines the encoder object.

Enumeration Type Documentation

enum ENC_LOG_State_e

Enumeration for the encoder log states.

Enumerator
ENC_LOG_STATE_IDLE	idle state
ENC_LOG_STATE_FREERUN	freerun state
ENC_LOG_STATE_ACQUIRE	acquire state

Definition at line 77 of file enc.h.

Function Documentation

void ENC_calcElecAngle	(	ENC_Handle	encHandle,
		uint32_t	posnCounts
	)

Reads encoder and returns the electrical degrees in Q24 format.

Parameters

[in]	encHandle	Handle to the ENC object
[in]	posnCounts	Current position counts from encoder

Returns: Nothing

Definition at line 129 of file enc.c.

References _ENC_Obj_::enc_elec_angle, _ENC_Obj_::enc_magnetic_angle, _ENC_Obj_::enc_slip_angle, _ENC_Obj_::enc_zero_offset, _ENC_Obj_::incremental_slip, _ENC_Obj_::mech_angle_gain, and _ENC_Obj_::num_pole_pairs.

_iq ENC_getElecAngle ( ENC_Handle encHandle )

inline

Returns the electrical angle.

Parameters

[in] encHandle Handle to the ENC object

Returns: Electrical angle in Q24

Definition at line 136 of file enc.h.

References _ENC_Obj_::enc_elec_angle.

_iq ENC_getFilteredSpeed ( ENC_Handle encHandle )

inline

Returns the low-pass filtered speed output.

Parameters

[in] encHandle Handle to the ENC object

Returns: LPF speed output in Q24

Definition at line 156 of file enc.h.

References _ENC_Obj_::speed_lpf_out.

_iq ENC_getMagneticAngle ( ENC_Handle encHandle )

inline

Returns the magnetic angle.

Parameters

[in] encHandle Handle to the ENC object

Returns: Magnetic angle in Q24

Definition at line 146 of file enc.h.

References _ENC_Obj_::enc_magnetic_angle.

int16_t ENC_getSpeedRPM ( ENC_Handle encHandle )

Returns the filtered speed in RPM.

Parameters

[in] encHandle Handle to the ENC object

Returns: RPM in Q0

Definition at line 300 of file enc.c.

References ENC_RPM_Q1, ENC_RPM_Q2, _ENC_Obj_::rpm_gain, and _ENC_Obj_::speed_lpf_out.

ENC_Handle ENC_init	(	void *	pMemory,
		const size_t	numBytes
	)

Initializes the encoder object.

Parameters

[in]	pMemory	Memory pointer to object
[in]	numBytes	Object size

Returns: Object handle

Definition at line 55 of file enc.c.

void ENC_run	(	ENC_Handle	encHandle,
		uint32_t	posnCounts,
		uint16_t	indextFlag,
		uint16_t	dirFlag,
		int16_t	log_flag
	)

Based on the encoder reading, computes the electrical angle and the electrical "speed".

Parameters

[in]	encHandle	Handle to the ENC object
[in]	posnCounts	Current position counts from encoder
[in]	indextFlag	If set, there was an index
[in]	dirFlag	Indicates direction of rotation
[in]	log_flag	If set, logs the encoder data

Returns: Nothing

Definition at line 163 of file enc.c.

References _ENC_Obj_::delta_enc, _ENC_Obj_::enc_elec_angle, ENC_LOG_DELTA_TRIGGER_THRES, ENC_LOG_LEN, ENC_LOG_STATE_ACQUIRE, ENC_LOG_STATE_FREERUN, ENC_LOG_STATE_IDLE, ENC_SPEED_COEFF_Q, _ENC_Obj_::enc_zero_offset, _ENC_Obj_::log, _ENC_Obj_::log_idx, _ENC_Obj_::log_state, _ENC_Obj_::mech_angle_gain, _ENC_Obj_::num_enc_slots, _ENC_Obj_::num_pole_pairs, _ENC_Obj_::post_trigger_cnt, _ENC_Obj_::post_trigger_len, _ENC_Obj_::prev_enc, _ENC_Obj_::run_flag, _ENC_Obj_::sample_count, _ENC_Obj_::sample_period, _ENC_Obj_::speed_gain, _ENC_Obj_::speed_lpf_cx, _ENC_Obj_::speed_lpf_cy, _ENC_Obj_::speed_lpf_out, _ENC_Obj_::trigger_delta, and _ENC_Obj_::trigger_idx.

void ENC_setIncrementalSlip	(	ENC_Handle	encHandle,
		_iq	incrementalSlip
	)

inline

Set the amount of incremental slip.

Parameters

[in]	encHandle	Handle to the ENC object
[in]	incrementalSlip	Amount of incremental slip in Electrical Angle

Definition at line 189 of file enc.h.

References _ENC_Obj_::incremental_slip.

void ENC_setRunFlag ( ENC_Handle encHandle )

inline

Start logging encoder data.

Parameters

[in] encHandle Handle to the ENC object

Definition at line 201 of file enc.h.

References _ENC_Obj_::run_flag.

void ENC_setup	(	ENC_Handle	encHandle,
		const int16_t	sample_period,
		const uint16_t	num_pole_pairs,
		const uint16_t	num_enc_slots,
		const uint32_t	enc_zero_offset,
		const float_t	full_scale_freq,
		const float_t	speed_update_freq,
		const float_t	speed_cutoff
	)

Initializes encoder object parameters.

Parameters

[in]	encHandle	Handle to the ENC object
[in]	sample_period	How often the encoder is read & processed
[in]	num_pole_pairs	Number of pole pairs in motor
[in]	num_enc_slots	Number of encoder slots
[in]	enc_zero_offset	Encoder zero offset in counts
[in]	full_scale_freq	Full scale speed for normalization
[in]	speed_update_freq	Update frequency in Hz for speed calculation
[in]	speed_cutoff	Speed calculation LPF cutoff frequency in Hz

Definition at line 68 of file enc.c.

References _ENC_Obj_::delta_enc, ENC_2PI, _ENC_Obj_::enc_elec_angle, ENC_LOG_LEN, ENC_LOG_STATE_IDLE, ENC_SPEED_COEFF_SCALING, ENC_SPEED_SCALING_FACTOR, _ENC_Obj_::enc_zero_offset, _ENC_Obj_::full_scale_freq, _ENC_Obj_::log, _ENC_Obj_::log_idx, _ENC_Obj_::log_state, _ENC_Obj_::mech_angle_gain, _ENC_Obj_::num_enc_slots, _ENC_Obj_::num_pole_pairs, _ENC_Obj_::post_trigger_cnt, _ENC_Obj_::post_trigger_len, _ENC_Obj_::prev_enc, _ENC_Obj_::rpm_gain, _ENC_Obj_::run_flag, _ENC_Obj_::sample_count, _ENC_Obj_::sample_period, _ENC_Obj_::speed_cutoff, _ENC_Obj_::speed_gain, _ENC_Obj_::speed_lpf_cx, _ENC_Obj_::speed_lpf_cy, _ENC_Obj_::speed_lpf_out, _ENC_Obj_::trigger_delta, and _ENC_Obj_::trigger_idx.

void ENC_setZeroOffset	(	ENC_Handle	encHandle,
		uint32_t	zeroOffset
	)

inline

Sets the value for the encoder object zero offset.

Parameters

[in]	encHandle	Handle to the ENC object
[in]	zeroOffset	New zero offset

Definition at line 214 of file enc.h.

References _ENC_Obj_::enc_zero_offset, and _ENC_Obj_::mech_angle_gain.

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Data Structure Documentation

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation