Encoders

Defines
#define	LEFT   0
	Left wheel.
#define	RIGHT   1
	Right wheel.
#define	ENCODER_MAX   1024
	Max value of valid encoder reading.
#define	ENCODER_MAGNET_FAILURE   1025
	Magnet misaligned - likely distance from encoder problem.
#define	ENCODER_MISALIGNED   1027
	Encoder misaligned - likely on XY plane.
#define	ENCODER_DATA_NOT_READY   1026
	Not enough time has passed - encoders not initialized in hardware.
#define	ENCODER_DELAY   20
	delay_ms argument after a full read is complete
#define	OCF   _BV(4)
#define	COF   _BV(3)
#define	LIN   _BV(2)
#define	MagINCn   _BV(1)
#define	MagDECn   _BV(0)
#define	BUFFER_SIZE   46
	Buffer size.
#define	ERR_VEL   1024
Functions
void	encoders_init (void)
	Initialize encoders.
int	encoder_read (char encoder)
	Read instantaneous encoder value.
int	encoder_get_x (char encoder)
	Get total distance traveled.
int	encoder_get_v (char encoder)
	Get instantaneous velocity.
int	encoder_get_dx (char encoder)
	Get total distance traveled.
void	encoder_rst_dx (char encoder)
	Reset distance counter.
int	encoder_get_tc (void)
	Get time count: The number of encoder reads that have occurred.
void	encoder_rst_tc (void)
	Reset the time count.
void	encoder_wait (int nReadings)
	Waits for the next n encoder reading, then returns.

---

Function Documentation

int encoder_get_dx

(

char

encoder

)

Get total distance traveled.

Gets the total distance covered by the specified encoder (in encoder clicks)

Parameters:

encoder

the encoder that you want to read, use LEFT or RIGHT

Returns:

The distance covered by the specified encoder.

Definition at line 114 of file encoders.c.

References LEFT, and RIGHT.

Referenced by encoder_get_x().

int encoder_get_tc

(

void

)

Get time count: The number of encoder reads that have occurred.

Get time count: The number of encoder reads that have occurred.

Returns:

The time count.

Definition at line 165 of file encoders.c.

int encoder_get_v

(

char

encoder

)

Get instantaneous velocity.

Get instantaneous velocity.

Parameters:

encoder

RIGHT or LEFT - the wheel you want the velocity for.

Returns:

The instantaneous velocity for the given wheel or twice the ERR_VEL if an error occurs (1024 * 2 = 2048)

Bug:

This uses hard coded values and results are inconsistent. Use at your own risk.

Definition at line 133 of file encoders.c.

int encoder_get_x

(

char

encoder

)

Get total distance traveled.

Note:

Simply calls encoder_get_dx.

Get total distance traveled.

Parameters:

encoder

the encoder that you want to read, either LEFT or RIGHT

Returns:

The distance covered by the specified encoder.

Note:

Simply calls encoder_get_dx.

Definition at line 103 of file encoders.c.

References encoder_get_dx().

int encoder_read

(

char

encoder

)

Read instantaneous encoder value.

Read instantaneous encoder value.

Parameters:

encoder

this is the encoder that you want to read. Valid arguments are LEFT and RIGHT

Returns:

the value of the specified encoder. -1 usually means low battery. values above ENCODER_MAX usually means phyiscal problems with the encoder.

Definition at line 87 of file encoders.c.

References LEFT, and RIGHT.

Referenced by odometry_reset().

void encoder_rst_dx

(

char

encoder

)

Reset distance counter.

Resets the distance accumulator for the specified encoder.

Parameters:

encoder

the encoder that you want to reset distance for

Definition at line 154 of file encoders.c.

References LEFT, and RIGHT.

void encoder_wait

(

int

n

)

Waits for the next n encoder reading, then returns.

Waits for the next n encoder reading, then returns.

Parameters:

n

Definition at line 182 of file encoders.c.