API Reference

as5600

CircuitPython helper library for the AMS AS5600 12-bit on-axis magnetic rotary position sensor

  • Author(s): Noel Anderson

Implementation Notes

Hardware:

Software and Dependencies:

class as5600.AS5600(i2c, address=_AS5600_DEFAULT_I2C_ADDR)

Initialize the AS5600 chip at address on i2c_bus.

Parameters:

  • i2c (I2C) – The I2C bus object.

  • address (int) – The I2C address of the device. Default is 0x36.

FAST_FILTER_THRESHOLD_10LSB = 7

Fast Filter Threshold (FTH) 10 LSB

FAST_FILTER_THRESHOLD_18LSB = 4

Fast Filter Threshold (FTH) 18 LSB

FAST_FILTER_THRESHOLD_21LSB = 5

Fast Filter Threshold (FTH) 21 LSB

FAST_FILTER_THRESHOLD_24LSB = 6

Fast Filter Threshold (FTH) 24 LSB

FAST_FILTER_THRESHOLD_6LSB = 1

Fast Filter Threshold (FTH) 6 LSB

FAST_FILTER_THRESHOLD_7LSB = 2

Fast Filter Threshold (FTH) 7 LSB

FAST_FILTER_THRESHOLD_9LSB = 3

Fast Filter Threshold (FTH) 9 LSB

FAST_FILTER_THRESHOLD_SLOW = 0

Fast Filter off. Slow Filter only

HYSTERESIS_1LSB = 1

Hysteresis (HYST) 1 LSB

HYSTERESIS_2LSB = 2

Hysteresis (HYST) 2 LSB

HYSTERESIS_3LSB = 3

Hysteresis (HYST) 3 LSB

HYSTERESIS_OFF = 0

Hysteresis (HYST) off

OUTPUT_STAGE_ANALOG_FULL = 0

Output Stage (OUTS) full range analog output 0-100% GND to VDD

OUTPUT_STAGE_ANALOG_REDUCED = 1

Output Stage (OUTS) reduced range analog output 10-90% GND to VDD

OUTPUT_STAGE_DIGITAL_PWM = 2

Output Stage (OUTS) digital PWM output

POWER_MODE_LPM1 = 1

Low Power (LPM1) mode - 3.4mA, Polling Time = 5mS

POWER_MODE_LPM2 = 2

Low Power (LPM2) mode - 1.8mA, Polling Time = 20mS

POWER_MODE_LPM3 = 3

Low Power (LPM3) mode - 1.5mA, Polling Time = 100mS

POWER_MODE_NOM = 0

Always on (PM) mode - 6.5mA

PWM_FREQUENCY_115HZ = 0

PWM Frequency (PWMF) 115Hz

PWM_FREQUENCY_230HZ = 1

PWM Frequency (PWMF) 230Hz

PWM_FREQUENCY_460HZ = 2

PWM Frequency (PWMF) 460Hz

PWM_FREQUENCY_920HZ = 3

PWM Frequency (PWMF) 920Hz

SLOW_FILTER_16X = 0

Slow Filter (SF) 16x

SLOW_FILTER_2X = 3

Slow Filter (SF) 2x

SLOW_FILTER_4X = 2

Slow Filter (SF) 4x

SLOW_FILTER_8X = 1

Slow Filter (SF) 8x

property angle

Get the current 12-bit angle value (ANGLE).

If zero_position() and max_position(), or max_angle() has been set then this value is scaled to those limits. Else it is scaled to 0-360 degrees, with 4095 representing 360 degrees.

Returns:

The current angle value as an integer.

Return type:

int

burn_in_angle()

Perform a permanent writing of ZPOS and MPOS values to non-volatile memory. These are set by zero_position() and max_position().

burn_in_angle() can only be executed sucessfully up to 3 times due to device restrictions. burn_in_angle() can only be executed if is_magnet_detected = True.

zmco shows how many times ZPOS and MPOS have been permanently written.

burn_in_settings()

Perform a permanent writing of MANG and CONFIG to non-volatile memory.

MANG is set by max_angle().

MANG can be written only if ZPOS and MPOS have never been permanently written (zmco = 0).

CONFIG contains the combination of all values set by the configuration methods.

These are watch_dog, power_mode, hysteresis, output_stage, pwm_frequency, fast_filter & slow_filter.

burn_in_settings() can be performed only one time due to device restrictions, and should be performed before burn_in_angle().

property fast_filter: int

Get and set the Fast Filter Threshold (FTH) configuration.

Valid values: FAST_FILTER_THRESHOLD_SLOW, FAST_FILTER_THRESHOLD_6LSB, FAST_FILTER_THRESHOLD_7LSB,

Returns:

The fast filter threshold value as an integer.

Return type:

int

property gain: int

Get the 8-bit Automatic Gain Control value (AGC).

Returns:

The AGC value as an integer.

Return type:

int

property hysteresis: int

Get and set the Hysteresis (HYST) configuration. Set this to avoid toggling of the output when the magnet is not moving.

Valid values: HYSTERESIS_OFF, HYSTERESIS_1LSB, HYSTERESIS_2LSB & HYSTERESIS_3LSB

Returns:

The hysteresis value as an integer.

Return type:

int

property is_magnet_detected: bool

Test MD Status Bit.

Returns:

True if a magnet is detected, False otherwise.

Return type:

bool

property is_magnet_too_strong: bool

Test MH Status Bit. True if AGC minimum gain overflow, magnet too strong

Returns:

True if the magnet is too strong, False otherwise.

Return type:

bool

property is_magnet_too_weak: bool

Test ML Status Bit. True if AGC maximum gain overflow, magnet too weak

Returns:

True if the magnet is too weak, False otherwise.

Return type:

bool

property magnitude: int

Get the 12-bit CORDIC (Coordinate Rotation Digital Computer) magnitude (MAGNITUDE).

Returns:

The magnitude value as an integer.

Return type:

int

property max_angle: int

Get and set the maximum anglular range (MANG) in degrees.

For applications which do not use the full 0 to 360 degree angular range, the output resolution can be enhanced by programming the range which is actually used. In this case, the full resolution of the output is automatically scaled to the programmed angular range. The angular range must be greater than 18 degrees.

It can also be set by a combination of zero_position & max_position (ZPOS and MPOS).

Returns:

The maximum angle in degrees as an integer.

Return type:

int

property max_position: int

Get and set the 12-bit maximum position (MPOS).

For applications which do not use the full 0 to 360 degree angular range, the output resolution can be enhanced by programming the range which is actually used. In this case, the full resolution of the output is automatically scaled to the programmed angular range. The angular range must be greater than 18 degrees.

Set by a combination of zero_position & max_position (ZPOS and MPOS).

It can also be set by max_angle.

Returns:

The maximum position as an integer.

Return type:

int

property output_stage: int

Get and set the Output Stage configuration. This controls the output of pin 3 (OUT) as either an analog or PWM signal.

Valid values: OUTPUT_STAGE_ANALOG_FULL, OUTPUT_STAGE_ANALOG_REDUCED, OUTPUT_STAGE_DIGITAL_PWM

Returns:

The output stage value as an integer.

Return type:

int

property power_mode: int

Get and set the Power Mode (PM) configuration.

Valid values: POWER_MODE_NOM, POWER_MODE_LPM1, POWER_MODE_LPM2 & POWER_MODE_LPM3

Returns:

The power mode as an integer.

Return type:

int

property pwm_frequency: int

Get and set the PWM Frequency (PWMF) configuration. Sets the frequency of the PWM output.

Ignored if output_stage is set as Analog. Valid values: PWM_FREQUENCY_115HZ, PWM_FREQUENCY_230HZ, PWM_FREQUENCY_460HZ & PWM_FREQUENCY_920HZ

Returns:

The PWM frequency value as an integer.

Return type:

int

property raw_angle

Get the current unscaled and unmodified 12-bit angle (RAWANGLE).

Returns:

The current raw angle as an integer.

Return type:

int

property slow_filter: int

Get and set the Slow Filter (SF) configuration.

Valid values: SLOW_FILTER_16X, SLOW_FILTER_8X, SLOW_FILTER_4X & SLOW_FILTER_2X

Returns:

The slow filter value as an integer.

Return type:

int

property watch_dog: bool

Get and set the Watchdog (WD) configuration. True enables the watchdog.

The watchdog configuration saves power by switching into low power mode LMP3 if the angle stays within the watchdog threshold of 4 LSB for at least one minute.

Returns:

The watchdog value as an integer.

Return type:

int

property zero_position: int

Get and set the 12-bit zero position (ZPOS).

For applications which do not use the full 0 to 360 degree angular range, the output resolution can be enhanced by programming the range which is actually used. In this case, the full resolution of the output is automatically scaled to the programmed angular range. The angular range must be greater than 18 degrees.

Set by a combination of zero_position & max_position (ZPOS and MPOS).

It can also be set by max_angle.

Returns:

The zero position as an integer.

Return type:

int

property zmco: int

Get the 8-bit burn count (ZMCO).

Returns:

The burn count as an integer.

Return type:

int