as5600.c File Reference

The AS5600 codec and driver. More...

#include "as5600.h"

Functions
uint16_t	as5600_u12 (const uint8_t *b)
	A 12-bit register pair, most significant byte first: RAW ANGLE, ANGLE or MAGNITUDE.
bool	as5600_status_possible (uint8_t status)
	Whether status is one an AS5600 can give: not ML and MH together.
bool	as5600_md (uint8_t status)
	The magnet bits of status.
bool	as5600_ml (uint8_t status)
	Read the ML bit of a STATUS value.
bool	as5600_mh (uint8_t status)
	Read the MH bit of a STATUS value.
int16_t	as5600_delta (uint16_t a, uint16_t b)
	a minus b on the circle, -2048 to 2047 counts: the shortest way from b to a.
int32_t	as5600_cdeg (int32_t counts)
	counts in hundredths of a degree, rounded to the nearest, halves away from zero.
void	as5600_init (as5600_t *d, sense_bus_t *bus)
	A part on bus at AS5600_ADDR, not yet probed.
static sense_state_t	probe (as5600_t *d)
	Probe the part: read STATUS and classify the answer.
bool	as5600_step (as5600_t *d, uint32_t now_ms)
	Every tick: probes the part when it is due – at the first call, and SENSE_RETRY_MS after it was found absent, wrong or offline.
sense_state_t	as5600_state (const as5600_t *d)
	The part's state as of the last probe.
sense_err_t	as5600_read_status (as5600_t *d, uint8_t *status)
	STATUS: 1 byte from 0x0B.
sense_err_t	as5600_read_raw (as5600_t *d, uint16_t *raw)
	RAW ANGLE: 2 bytes from 0x0C, 0 to 4095; the same rule.
sense_err_t	as5600_read_agc (as5600_t *d, uint8_t *agc)
	AGC: 1 byte from 0x1A; the same rule.
sense_err_t	as5600_read_mag (as5600_t *d, uint16_t *magnitude)
	MAGNITUDE: 2 bytes from 0x1B, 0 to 4095; the same rule.
sense_err_t	as5600_read_angle (as5600_t *d, uint8_t *status, uint16_t *raw)
	STATUS, then RAW ANGLE: two transactions.
sense_err_t	as5600_read_magnitude (as5600_t *d, uint8_t *agc, uint16_t *magnitude)
	AGC, then MAGNITUDE: two transactions; the same rule.

Detailed Description

The AS5600 codec and driver.

See as5600.h.

SPDX-License-Identifier: MIT

Function Documentation

as5600_cdeg()

int32_t as5600_cdeg

(

int32_t

counts

)

counts in hundredths of a degree, rounded to the nearest, halves away from zero.

Any int32_t is accepted. Above |counts| 244,335,917 the result saturates at +-2,147,483,647.

Parameters

counts

Angle in counts; 4096 counts make a turn.

Returns

The angle in hundredths of a degree.

as5600_delta()

int16_t as5600_delta	(	uint16_t	a,
		uint16_t	b )

a minus b on the circle, -2048 to 2047 counts: the shortest way from b to a.

Both are taken modulo 4096.

Parameters

a	An angle, in counts.
b	An angle, in counts.

Returns

a - b in counts, -2048 to 2047.

as5600_init()

void as5600_init	(	as5600_t *	d,
		sense_bus_t *	bus )

A part on bus at AS5600_ADDR, not yet probed.

Parameters

d	The driver.
bus	The sensor bus the part sits on.

as5600_md()

bool as5600_md

(

uint8_t

status

)

The magnet bits of status.

RAW ANGLE is a position only with MD.

Parameters

status

The STATUS byte.

Returns

true when MD (magnet detected) is set.

as5600_mh()

bool as5600_mh

(

uint8_t

status

)

Read the MH bit of a STATUS value.

Parameters

status

The STATUS byte.

Returns

true when MH (magnet too strong) is set.

as5600_ml()

bool as5600_ml

(

uint8_t

status

)

Read the ML bit of a STATUS value.

Parameters

status

The STATUS byte.

Returns

true when ML (magnet too weak) is set.

as5600_read_agc()

sense_err_t as5600_read_agc	(	as5600_t *	d,
		uint8_t *	agc )

AGC: 1 byte from 0x1A; the same rule.

Parameters

d	The driver.
agc	Receives the AGC byte.

Returns

SENSE_OK, or the bus error.

as5600_read_angle()

sense_err_t as5600_read_angle	(	as5600_t *	d,
		uint8_t *	status,
		uint16_t *	raw )

STATUS, then RAW ANGLE: two transactions.

On anything but SENSE_OK both are left as they were.

Parameters

d	The driver.
status	Receives the STATUS byte.
raw	Receives the angle, 0 to 4095.

Returns

SENSE_OK, or the bus error.

as5600_read_mag()

sense_err_t as5600_read_mag	(	as5600_t *	d,
		uint16_t *	magnitude )

MAGNITUDE: 2 bytes from 0x1B, 0 to 4095; the same rule.

Parameters

d	The driver.
magnitude	Receives the magnitude, 0 to 4095.

Returns

SENSE_OK, or the bus error.

as5600_read_magnitude()

sense_err_t as5600_read_magnitude	(	as5600_t *	d,
		uint8_t *	agc,
		uint16_t *	magnitude )

AGC, then MAGNITUDE: two transactions; the same rule.

Parameters

d	The driver.
agc	Receives the AGC byte.
magnitude	Receives the magnitude, 0 to 4095.

Returns

SENSE_OK, or the bus error.

as5600_read_raw()

sense_err_t as5600_read_raw	(	as5600_t *	d,
		uint16_t *	raw )

RAW ANGLE: 2 bytes from 0x0C, 0 to 4095; the same rule.

Parameters

d	The driver.
raw	Receives the angle, 0 to 4095.

Returns

SENSE_OK, or the bus error.

as5600_read_status()

sense_err_t as5600_read_status	(	as5600_t *	d,
		uint8_t *	status )

STATUS: 1 byte from 0x0B.

On anything but SENSE_OK status is left as it was.

Parameters

d	The driver.
status	Receives the STATUS byte.

Returns

SENSE_OK, or the bus error.

as5600_state()

sense_state_t as5600_state

(

const as5600_t *

d

)

The part's state as of the last probe.

Parameters

d	The driver.

Returns

The sense_state_t of the part.

as5600_status_possible()

bool as5600_status_possible

(

uint8_t

status

)

Whether status is one an AS5600 can give: not ML and MH together.

Bits 7, 6, 2, 1 and 0 are not looked at.

Parameters

status

The STATUS byte.

Returns

false when ML and MH are both set, else true.

as5600_step()

bool as5600_step	(	as5600_t *	d,
		uint32_t	now_ms )

Every tick: probes the part when it is due – at the first call, and SENSE_RETRY_MS after it was found absent, wrong or offline.

Returns whether it is online.

Parameters

d	The driver.
now_ms	The current time, in ms.

Returns

true when the part is online.

as5600_u12()

uint16_t as5600_u12

(

const uint8_t *

b

)

A 12-bit register pair, most significant byte first: RAW ANGLE, ANGLE or MAGNITUDE.

0 to 4095.

Parameters

b	The two bytes, high byte first.

Returns

The 12-bit value, 0 to 4095.

probe()

sense_state_t probe ( as5600_t * d )

static

Probe the part: read STATUS and classify the answer.

Parameters

d	The driver.

Returns

SENSE_PART_ABSENT when the read fails, SENSE_PART_WRONG_ID when ML and MH are both set, else SENSE_PART_ONLINE.