Bosch BMA222 3-axis accelerometer driver.

This file contains functions for initializing and reading data from a Bosch BMA222 3-axis accelerometer.

#include "bma222.h"
#include "bma_axis.inc.c"

Functions
static bool	bma222_device_id (sensor_hal_t hal, sensor_data_t data)
	Read BMA222 device ID and revision numbers. More...

static bool	bma222_event (sensor_t sensor, sensor_event_t sensor_event, sensor_event_callback_t callback, bool enable)
	Enable or disable BMA222 sensor events. More...

static bool	bma222_get_accel (sensor_hal_t hal, sensor_data_t data)
	Read BMA222 acceleration data. More...

static bool	bma222_get_temperature (sensor_hal_t hal, sensor_data_t data)
	Read BMA222 temperature data. More...

static bool	bma222_get_threshold (sensor_hal_t hal, sensor_threshold_desc_t threshold)
	Get event threshold value. More...

bool	bma222_init (sensor_t *sensor, int resvd)
	Bosch BMA222 accelerometer driver initialization. More...

static bool	bma222_ioctl (sensor_t sensor, sensor_command_t cmd, void arg)
	BMA222 ioctl control entry point. More...

static void	bma222_isr (volatile void *arg)
	Bosch BMA222 driver interrupt service routine. More...

static bool	bma222_read (sensor_t sensor, sensor_read_t type, sensor_data_t data)
	Read sensor data. More...

static bool	bma222_selftest (sensor_t sensor, int test_code, void *arg)
	Run BMA222 self-tests. More...

static bool	bma222_set_bandwidth (sensor_hal_t *hal, int16_t band)
	Set the BMA222 digital filter cut-off frequency. More...

static bool	bma222_set_range (sensor_hal_t *hal, int16_t range)
	Set the BMA222 full scale acceleration range. More...

static bool	bma222_set_state (sensor_t *sensor, sensor_state_t mode)
	Set the BMA222 execution mode. More...

static bool	bma222_set_tap (sensor_hal_t hal, sensor_tap_params_t params)
	BMA222 tap detection configuration. More...

static bool	bma222_set_threshold (sensor_hal_t hal, sensor_threshold_desc_t threshold)
	Set event threshold value. More...

static void	bma222_sleep_en (sensor_hal_t *hal, bool sleep)
	Enable or disable the BMA222 sleep mode. More...

Variables
static const sensor_map_t	band_table []
	Bosch BMA222 Bandwidth Table (hertz, register value) More...

static sensor_event_callback_t	event_cb [5]
	Sensor Event Callback Descriptors (data=0, motion=1, low-g=2, high-g=3, tap=4) More...

struct {
union {
uint8_t status_byte [4]
	Status bytes. More...

struct {
uint8_t d_tap_int: 1
	double-tap interrupt triggered More...

uint8_t data_int: 1
	New data interrupt triggered. More...

uint8_t flat: 1
	Orientation with respect to gravity. More...

uint8_t flat_int: 1
	< Status fields More...

uint8_t high_first_x: 1
	x-axis high-g interrupt More...

uint8_t high_first_y: 1
	y-axis high-g interrupt More...

uint8_t high_first_z: 1
	z-axis high-g interrupt More...

uint8_t high_int: 1
	High-g criteria triggered. More...

uint8_t high_sign: 1
	High-g interrupt sign. More...

uint8_t low_int: 1
	Low-g criteria triggered. More...

uint8_t orient: 3
	orientation with respect to gravity More...

uint8_t orient_int: 1
	Orientation interrupt triggered. More...

uint8_t reserved_09: 1

uint8_t reserved_0a: 7

uint8_t s_tap_int: 1
	Single-tap interrupt triggered. More...

uint8_t slope_first_x: 1
	x-axis any-motion interrupt More...

uint8_t slope_first_y: 1
	y-axis any-motion interrupt More...

uint8_t slope_first_z: 1
	z-axis any-motion interrupt More...

uint8_t slope_int: 1
	Slope criteria triggered. More...

uint8_t slope_sign: 1
	Axis motion direction. More...

uint8_t tap_first_x: 1
	x-axis tap interrupt More...

uint8_t tap_first_y: 1
	y-axis tap interrupt More...

uint8_t tap_first_z: 1
	z-axis tap interrupt More...

uint8_t tap_sign: 1
	Tap axis motion direction. More...

} status_field

}

bma_axis_t acc [3]
	Acceleration data. More...

int8_t temp
	Temperature data. More...

}	event_regs
	Sensor Event Registers. More...

static const sensor_map_t	range_table []
	Bosch BMA222 Range Table (milli-g, register value) More...

static bool bma222_device_id	(	sensor_hal_t *	hal,
		sensor_data_t *	data
	)

static

Read BMA222 device ID and revision numbers.

This function reads the accelerometer hardware identification registers and returns these values in the specified data structure.

Parameters

hal	Address of an initialized sensor hardware descriptor.
data	Address of sensor_data_t structure to return values.

Returns: bool true if the call succeeds, else false is returned.

References BMA222_CHIP_ID, sensor_hal::bus, sensor_data_t::device, sensor_bus_get, bus_desc_t::status, and STATUS_OK.

Referenced by bma222_read().

static bool bma222_event	(	sensor_t *	sensor,
		sensor_event_t	sensor_event,
		sensor_event_callback_t *	callback,
		bool	enable
	)

static

Enable or disable BMA222 sensor events.

Parameters

sensor	Address of an initialized sensor device descriptor
sensor_event	Specifies the sensor event type
callback	Application-defined event callback handler descriptor
enable	Enable flag: true = enable event, false = disable event

Returns: bool true if the call succeeds, else false is returned

References BMA222_16_INTR_EN, BMA222_17_INTR_EN, BMA222_D_TAP_EN, BMA222_DATA_EN, BMA222_HIGH_EN_X, BMA222_HIGH_EN_Y, BMA222_HIGH_EN_Z, BMA222_LOW_EN, BMA222_S_TAP_EN, BMA222_SLOPE_EN_X, BMA222_SLOPE_EN_Y, BMA222_SLOPE_EN_Z, sensor_desc::hal, sensor_bus_get, sensor_bus_put, SENSOR_EVENT_HIGH_G, SENSOR_EVENT_LOW_G, SENSOR_EVENT_MOTION, SENSOR_EVENT_NEW_DATA, SENSOR_EVENT_TAP, and status.

Referenced by bma222_init(), and bma222_ioctl().

static bool bma222_get_accel	(	sensor_hal_t *	hal,
		sensor_data_t *	data
	)

static

Read BMA222 acceleration data.

This function obtains accelerometer data for all three axes of the Bosch device. The data is read from three device registers using a multi-byte bus transfer.

Along with the actual sensor data, the LSB byte contains a "new" flag indicating if the data for this axis has been updated since the last time the axis data was read. Reading either LSB or MSB data will clear this flag.

Parameters

sensor	Address of an initialized sensor device descriptor.
data	The address of a vector storing sensor axis data.

Returns: bool true if the call succeeds, else false is returned.

References sensor_hal::burst_addr, event_regs, and sensor_bus_read.

Referenced by bma222_ioctl(), and bma222_read().

static bool bma222_get_temperature	(	sensor_hal_t *	hal,
		sensor_data_t *	data
	)

static

Read BMA222 temperature data.

This function reads temperature data, where center temperature 24 C corresponds to a value 0x00 read from the temperature register with temperature slope 0.5 C/LSB.

Parameters

hal	Address of an initialized sensor hardware descriptor.
data	The address where temperature samples are returned.

Returns: bool true if the call succeeds, else false is returned.

References BMA222_TEMP, BMA222_TEMP_OFFSET, sensor_hal::bus, sensor_data_t::scaled, sensor_bus_get, bus_desc_t::status, STATUS_OK, and sensor_data_t::temperature.

Referenced by bma222_read().

static bool bma222_get_threshold	(	sensor_hal_t *	hal,
		sensor_threshold_desc_t *	threshold
	)

static

Get event threshold value.

Parameters

hal	Address of an initialized sensor hardware descriptor.
threshold	Address of threshold descriptor.

Returns: bool true if the call succeeds, else false is returned.

References BMA222_HIGH_G_THRESHOLD, BMA222_LOW_G_THRESHOLD, BMA222_SLOPE_THRESHOLD, BMA222_TAP_CONFIG, BMA222_TAP_TH_FIELD, sensor_hal::bus, raw_to_scaled(), sensor_bus_get, sensor_reg_fieldget, SENSOR_THRESHOLD_HIGH_G, SENSOR_THRESHOLD_LOW_G, SENSOR_THRESHOLD_MOTION, SENSOR_THRESHOLD_TAP, bus_desc_t::status, STATUS_OK, sensor_threshold_desc_t::type, and sensor_threshold_desc_t::value.

Referenced by bma222_ioctl().

bool bma222_init	(	sensor_t *	sensor,
		int	resvd
	)

Bosch BMA222 accelerometer driver initialization.

This is the main initialization function for the BMA222 device.

Parameters

sensor	Address of a sensor device descriptor.
resvd	Reserved value.

Returns: bool true if the call succeeds, else false is returned.

References ARRAYSIZE, band_table, sensor_hal::bandwidth, BMA222_CHIP_ID, BMA222_DATA_RESOLUTION, bma222_event(), BMA222_ID_VAL, bma222_ioctl(), bma222_isr(), BMA222_NEW_DATA_X, bma222_read(), bma222_selftest(), bma222_set_state(), sensor_hal::burst_addr, sensor_hal::bus, sensor_desc::drv, sensor_device_t::func, sensor_desc::hal, sensor_hal::mcu_sigint, sensor_hal::range, range_table, sensor_funcs_t::read, sensor_hal::resolution, sensor_bus_get, SENSOR_CAPS_3_AXIS, SENSOR_CAPS_AUX_TEMP, SENSOR_CAPS_HI_G_EVENT, SENSOR_CAPS_LO_G_EVENT, SENSOR_CAPS_SELFTEST, SENSOR_CAPS_TAP_EVENT, SENSOR_CAPS_TILT_EVENT, sensor_irq_connect(), SENSOR_SCALE_milli, SENSOR_STATE_RESET, SENSOR_UNITS_g0, SENSOR_VENDOR_BOSCH, status, bus_desc_t::status, and STATUS_OK.

static bool bma222_ioctl	(	sensor_t *	sensor,
		sensor_command_t	cmd,
		void *	arg
	)

static

BMA222 ioctl control entry point.

Parameters

hal	Address of an initialized sensor hardware descriptor.
cmd	Command to execute
arg	Argument for command (varies)

Returns: bool true if the call succeeds, else false is returned.

References sensor_data_t::axis, bma222_event(), bma222_get_accel(), bma222_get_threshold(), bma222_set_bandwidth(), bma222_set_range(), bma222_set_state(), bma222_set_tap(), bma222_set_threshold(), sensor_desc::err, sensor_desc::hal, sensor_desc::mod, sensor_data_t::scaled, SENSOR_DISABLE_EVENT, SENSOR_ENABLE_EVENT, SENSOR_ERR_UNSUPPORTED, SENSOR_GET_THRESHOLD, SENSOR_READ_VECTOR, SENSOR_SET_BANDWIDTH, SENSOR_SET_RANGE, SENSOR_SET_STATE, SENSOR_SET_TAP, SENSOR_SET_THRESHOLD, SENSOR_STATE_NORMAL, SENSOR_STATE_RESET, vector3_t::x, vector3_t::y, and vector3_t::z.

Referenced by bma222_init().

static void bma222_isr ( volatile void * arg )

static

Bosch BMA222 driver interrupt service routine.

This is the common interrupt service routine for all enabled BMA222 interrupt events. Five different types of interrupts can be programmed. All interrupt criteria are combined and drive the interrupt pad with a Boolean OR condition.

Interrupt criteria are tested against values from the BMA222 digital filter output. All thresholds are scaled using the current device range. Timings for high and low acceleration are absolute values (1 LSB of HG_dur and LG_dur registers corresponds to 1 millisecond, +/- 10%). Timing for the any-motion interrupt and alert detection are proportional to the bandwidth setting.

This routine handles interrupts generated when low-g, high-g, any-motion, alert, and new data criteria are satisfied and the corresponding event notification is enabled in the device.

The BMA222 device does not provide any way to definitively identify an any-motion interrupt once it has occurred. So, if a handler has been installed for that event, it will always be called by this routine, and the SENSOR_EVENT_MOTION indicator will be set in the event type field.

Parameters

arg	The address of the driver sensor_hal_t descriptor.

Returns: Nothing.

References sensor_hal::burst_addr, sensor_hal::bus, sensor_event_data_t::data, sensor_event_data_t::event, event_regs, sensor_event_callback_t::handler, bus_desc_t::no_wait, sensor_data_t::scaled, sensor_bus_read, SENSOR_EVENT_D_TAP, SENSOR_EVENT_HIGH_G, SENSOR_EVENT_LOW_G, SENSOR_EVENT_MOTION, SENSOR_EVENT_NEW_DATA, SENSOR_EVENT_S_TAP, SENSOR_EVENT_UNKNOWN, sensor_timestamp(), bus_desc_t::status, STATUS_OK, and sensor_data_t::timestamp.

Referenced by bma222_init().

static bool bma222_read	(	sensor_t *	sensor,
		sensor_read_t	type,
		sensor_data_t *	data
	)

static

Read sensor data.

This routine calls the appropriate internal data function to obtain the specified type of data from the sensor device.

Parameters

sensor	Address of an initialized sensor device descriptor.
type	Type of sensor data to read.
data	The address where data values are returned.

Returns: bool true if the call succeeds, else false is returned.

References bma222_device_id(), bma222_get_accel(), bma222_get_temperature(), sensor_desc::err, sensor_desc::hal, SENSOR_ERR_FUNCTION, SENSOR_READ_ACCELERATION, SENSOR_READ_ID, and SENSOR_READ_TEMPERATURE.

Referenced by bma222_init().

static bool bma222_selftest	(	sensor_t *	sensor,
		int *	test_code,
		void *	arg
	)

static

Run BMA222 self-tests.

Parameters

sensor	Address of an initialized sensor device descriptor.
test_code	Address of a device-specific numeric test code.
arg	Device-specific self-test argument options.

Returns: bool true if the call succeeds, else false is returned.

References SENSOR_TEST_DEFLECTION.

Referenced by bma222_init().

static bool bma222_set_bandwidth	(	sensor_hal_t *	hal,
		int16_t	band
	)

static

Set the BMA222 digital filter cut-off frequency.

Parameters

hal	Address of an initialized sensor hardware descriptor.
band	The index of a driver-specific bandwidth table entry.

Returns: bool true if the call succeeds, else false is returned.

References BMA222_BANDWIDTH, sensor_hal::bus, sensor_bus_put, bus_desc_t::status, and STATUS_OK.

Referenced by bma222_ioctl().

static bool bma222_set_range	(	sensor_hal_t *	hal,
		int16_t	range
	)

static

Set the BMA222 full scale acceleration range.

Parameters

hal	Address of an initialized sensor hardware descriptor.
range	The index of a driver-specific range table entry.

Returns: bool true if the call succeeds, else false is returned.

References BMA222_G_RANGE, sensor_hal::bus, sensor_bus_put, bus_desc_t::status, and STATUS_OK.

Referenced by bma222_ioctl().

static bool bma222_set_state	(	sensor_t *	sensor,
		sensor_state_t	mode
	)

static

Set the BMA222 execution mode.

This routine sets a specified BMA222 execution state to one of the following:

SENSOR_STATE_SUSPEND or SENSOR_STATE_LOWEST_POWER The BMA222 can be put into a suspend mode to easily achieve a power consumption below 1uA. In this mode all analog modules except for power-on reset will be disabled. Only reads through the serial interface are supported during suspend.

SENSOR_STATE_SLEEP or SENSOR_STATE_LOW_POWER This option sets the BMA222 to a low-power mode. In this mode, the device periodically wakes up, evaluates acceleration data with respect to interrupt criteria defined by the user and goes back to sleep if no interrupt has occurred using the following procedure:

Wake-up
Enable analog front-end and convert acceleration data until the low-pass filters have settled.
Enable interrupt controller and evaluate interrupt conditions. Once interrupt conditions are evaluated and no interrupt has occurred, the chip goes back to sleep. If no interrupts are enabled, acceleration for all three axes are converted once before the chip goes back to sleep.
Sleep for the programmed duration. Available sleep durations are 2ms, 10ms, 25ms, 50ms, 100ms, 500ms, 1s, and 2s.

SENSOR_STATE_NORMAL or SENSOR_STATE_HIGHEST_POWER In normal mode the sensor IC data and status registers can be accessed without restriction. The device current consumption is typically 250 microamps in this state.

SENSOR_STATE_X_AXIS_STANDBY SENSOR_STATE_Y_AXIS_STANDBY SENSOR_STATE_Z_AXIS_STANDBY In order to optimize further power consumption of the BMA222, data evaluation of individual axes can be deactivated.

SENSOR_STATE_RESET This function resets the device and internal registers to the power-up default settings.

In the wake-up mode, the BMA222 automatically switches from sleep mode to normal mode after a delay defined by a programmable wake_up_pause value. After transitioning from sleep to normal mode, acceleration data acquisition and interrupt verification are performed. The sensor automatically returns to sleep mode again if no interrupt criteria are satisfied.

Parameters

sensor	Address of a sensor device descriptor.
mode	A specified sensor operational mode.

Returns: bool true if the call succeeds, else false is returned.

References BMA222_POWER_MODES, BMA222_RESET, bma222_sleep_en(), BMA222_SOFTRESET, BMA222_SUSPEND, sensor_desc::hal, sensor_desc::mod, sensor_bus_put, SENSOR_STATE_HIGHEST_POWER, SENSOR_STATE_LOW_POWER, SENSOR_STATE_LOWEST_POWER, SENSOR_STATE_NORMAL, SENSOR_STATE_RESET, SENSOR_STATE_SLEEP, and SENSOR_STATE_SUSPEND.

Referenced by bma222_init(), and bma222_ioctl().

static bool bma222_set_tap	(	sensor_hal_t *	hal,
		sensor_tap_params_t *	params
	)

static

BMA222 tap detection configuration.

Parameters

hal	Address of an initialized sensor hardware descriptor.
params	Address of an initialized tap parameter structure.

Returns: bool true if the call succeeds, else false is returned.

Referenced by bma222_ioctl().

static bool bma222_set_threshold	(	sensor_hal_t *	hal,
		sensor_threshold_desc_t *	threshold
	)

static

Set event threshold value.

Parameters

hal	Address of an initialized sensor hardware descriptor.
threshold	Address of threshold descriptor.

Returns: bool true if the call succeeds, else false is returned.

References BMA222_HIGH_G_THRESHOLD, BMA222_LOW_G_THRESHOLD, BMA222_SLOPE_THRESHOLD, BMA222_TAP_CONFIG, BMA222_TAP_TH_FIELD, sensor_hal::bus, scaled_to_raw(), sensor_bus_put, sensor_reg_fieldset, SENSOR_THRESHOLD_HIGH_G, SENSOR_THRESHOLD_LOW_G, SENSOR_THRESHOLD_MOTION, SENSOR_THRESHOLD_TAP, bus_desc_t::status, STATUS_OK, sensor_threshold_desc_t::type, and sensor_threshold_desc_t::value.

Referenced by bma222_ioctl().

static void bma222_sleep_en	(	sensor_hal_t *	hal,
		bool	sleep
	)

inlinestatic

Enable or disable the BMA222 sleep mode.

This routine enables or disables the BMA222 sleep mode depending upon the value of the parameter; a value enables sleep mode and a value disables sleep mode by setting or clearing the 'sleep_en' bit, respectively.

Parameters

hal	Address of an initialized sensor hardware descriptor.
sleep	Set flag to enable sleep mode.

Returns: Nothing

References BMA222_LOWPOWER_EN, BMA222_POWER_MODES, BMA222_SLEEP_DUR_1ms, and sensor_bus_put.

Referenced by bma222_set_state().

bma_axis_t acc[3]

Acceleration data.

const sensor_map_t band_table[]

static

Initial value:

= {
    {{   8}, BMA222_BANDWIDTH_8Hz  }, 
    {{  16}, BMA222_BANDWIDTH_16Hz }, 
    {{  31}, BMA222_BANDWIDTH_31Hz }, 
    {{  63}, BMA222_BANDWIDTH_63Hz }, 
    {{ 125}, BMA222_BANDWIDTH_125Hz}, 
    {{ 250}, BMA222_BANDWIDTH_250Hz}, 
    {{ 500}, BMA222_BANDWIDTH_500Hz}, 
    {{1000}, BMA222_BANDWIDTH_1000Hz} 
}

Bosch BMA222 Bandwidth Table (hertz, register value)

Referenced by bma222_init().

uint8_t d_tap_int

double-tap interrupt triggered

uint8_t data_int

New data interrupt triggered.

sensor_event_callback_t event_cb[5]

static

Initial value:

= {
    {.handler = default_event_handler},
    {.handler = default_event_handler},
    {.handler = default_event_handler},
    {.handler = default_event_handler},
    {.handler = default_event_handler}
}

Sensor Event Callback Descriptors (data=0, motion=1, low-g=2, high-g=3, tap=4)

struct { ... } event_regs

Sensor Event Registers.

Referenced by bma222_get_accel(), and bma222_isr().

uint8_t flat

Orientation with respect to gravity.

uint8_t flat_int

< Status fields

Flat interrupt triggered

uint8_t high_first_x

x-axis high-g interrupt

uint8_t high_first_y

y-axis high-g interrupt

uint8_t high_first_z

z-axis high-g interrupt

uint8_t high_int

High-g criteria triggered.

uint8_t high_sign

High-g interrupt sign.

uint8_t low_int

Low-g criteria triggered.

uint8_t orient

orientation with respect to gravity

uint8_t orient_int

Orientation interrupt triggered.

const sensor_map_t range_table[]

static

Initial value:

= {
    {{ 2000}, BMA222_RANGE_2G},
    {{ 4000}, BMA222_RANGE_4G},
    {{ 8000}, BMA222_RANGE_8G},
    {{16000}, BMA222_RANGE_16G}
}

Bosch BMA222 Range Table (milli-g, register value)

Referenced by bma222_init().

uint8_t reserved_09

uint8_t reserved_0a

uint8_t s_tap_int

Single-tap interrupt triggered.

uint8_t slope_first_x

x-axis any-motion interrupt

uint8_t slope_first_y

y-axis any-motion interrupt

uint8_t slope_first_z

z-axis any-motion interrupt

uint8_t slope_int

Slope criteria triggered.

uint8_t slope_sign

Axis motion direction.

uint8_t status_byte[4]

Status bytes.

struct { ... } status_field

uint8_t tap_first_x

x-axis tap interrupt

uint8_t tap_first_y

y-axis tap interrupt

uint8_t tap_first_z

z-axis tap interrupt

uint8_t tap_sign

Tap axis motion direction.

int8_t temp

Temperature data.

Microchip® Advanced Software Framework

Functions

Variables