Atmel Software Framework

bma250.c File Reference

Bosch BMA250 3-axis accelerometer driver.

This file contains functions for initializing and reading data from a Bosch BMA250 3-axis accelerometer.

Copyright (c) 2014-2015 Atmel Corporation. All rights reserved.

#include "bma250.h"
#include "bma_axis.inc.c"

Functions

static bool bma250_device_id (sensor_hal_t *hal, sensor_data_t *data)
 Read BMA250 device ID and revision numbers. More...
 
static bool bma250_event (sensor_t *sensor, sensor_event_t sensor_event, sensor_event_callback_t *callback, bool enable)
 Enable or disable BMA250 sensor events. More...
 
static bool bma250_get_accel (sensor_hal_t *hal, sensor_data_t *data)
 Read BMA250 acceleration data. More...
 
static bool bma250_get_temperature (sensor_hal_t *hal, sensor_data_t *data)
 Read BMA250 temperature data. More...
 
static bool bma250_get_threshold (sensor_hal_t *hal, sensor_threshold_desc_t *threshold)
 Get event threshold value. More...
 
bool bma250_init (sensor_t *sensor, int resvd)
 Bosch BMA250 accelerometer driver initialization. More...
 
static bool bma250_ioctl (sensor_t *sensor, sensor_command_t cmd, void *arg)
 BMA250 ioctl control entry point. More...
 
static void bma250_isr (volatile void *arg)
 Bosch BMA250 driver interrupt service routine. More...
 
static bool bma250_read (sensor_t *sensor, sensor_read_t type, sensor_data_t *data)
 Read sensor data. More...
 
static bool bma250_selftest (sensor_t *sensor, int *test_code, void *arg)
 Run BMA250 self-tests. More...
 
static bool bma250_set_bandwidth (sensor_hal_t *hal, int16_t band)
 Set the BMA250 digital filter cut-off frequency. More...
 
static bool bma250_set_range (sensor_hal_t *hal, int16_t range)
 Set the BMA250 full scale acceleration range. More...
 
static bool bma250_set_state (sensor_t *sensor, sensor_state_t mode)
 Set the BMA250 execution mode. More...
 
static bool bma250_set_tap (sensor_hal_t *hal, sensor_tap_params_t *params)
 BMA250 tap detection configuration. More...
 
static bool bma250_set_threshold (sensor_hal_t *hal, sensor_threshold_desc_t *threshold)
 Set event threshold value. More...
 
static void bma250_sleep_en (sensor_hal_t *hal, bool sleep)
 Enable or disable the BMA250 sleep mode. More...
 

Variables

static const sensor_map_t band_table []
 Bosch BMA250 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 BMA250 Range Table (milli-g, register value) More...
 

static bool bma250_device_id ( sensor_hal_t hal,
sensor_data_t data 
)
static

Read BMA250 device ID and revision numbers.

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

Parameters
halAddress of an initialized sensor hardware descriptor.
dataAddress of sensor_data_t structure to return values.
Returns
bool true if the call succeeds, else false is returned.

References BMA250_CHIP_ID, sensor_hal::bus, sensor_data_t::device, sensor_bus_get, bus_desc_t::status, and STATUS_OK.

Referenced by bma250_read().

static bool bma250_event ( sensor_t sensor,
sensor_event_t  sensor_event,
sensor_event_callback_t callback,
bool  enable 
)
static

Enable or disable BMA250 sensor events.

Parameters
sensorAddress of an initialized sensor device descriptor
sensor_eventSpecifies the sensor event type
callbackApplication-defined event callback handler descriptor
enableEnable flag: true = enable event, false = disable event
Returns
bool true if the call succeeds, else false is returned

References BMA250_16_INTR_EN, BMA250_17_INTR_EN, BMA250_D_TAP_EN, BMA250_DATA_EN, BMA250_HIGH_EN_X, BMA250_HIGH_EN_Y, BMA250_HIGH_EN_Z, BMA250_LOW_EN, BMA250_S_TAP_EN, BMA250_SLOPE_EN_X, BMA250_SLOPE_EN_Y, BMA250_SLOPE_EN_Z, callback, 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 bma250_init(), and bma250_ioctl().

static bool bma250_get_accel ( sensor_hal_t hal,
sensor_data_t data 
)
static

Read BMA250 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
sensorAddress of an initialized sensor device descriptor.
dataThe 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 bma250_ioctl(), and bma250_read().

static bool bma250_get_temperature ( sensor_hal_t hal,
sensor_data_t data 
)
static

Read BMA250 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
halAddress of an initialized sensor hardware descriptor.
dataThe address where temperature samples are returned.
Returns
bool true if the call succeeds, else false is returned.

References BMA250_TEMP, BMA250_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 bma250_read().

static bool bma250_get_threshold ( sensor_hal_t hal,
sensor_threshold_desc_t threshold 
)
static

Get event threshold value.

Parameters
halAddress of an initialized sensor hardware descriptor.
thresholdAddress of threshold descriptor.
Returns
bool true if the call succeeds, else false is returned.

References BMA250_HIGH_G_THRESHOLD, BMA250_LOW_G_THRESHOLD, BMA250_SLOPE_THRESHOLD, BMA250_TAP_CONFIG, BMA250_TAP_TH_FIELD, raw_to_scaled(), sensor_bus_get, sensor_reg_fieldget, SENSOR_THRESHOLD_HIGH_G, SENSOR_THRESHOLD_LOW_G, SENSOR_THRESHOLD_MOTION, SENSOR_THRESHOLD_TAP, SENSOR_THRESHOLD_TILT, sensor_threshold_desc_t::type, and sensor_threshold_desc_t::value.

Referenced by bma250_ioctl().

static bool bma250_ioctl ( sensor_t sensor,
sensor_command_t  cmd,
void *  arg 
)
static
static void bma250_isr ( volatile void *  arg)
static

Bosch BMA250 driver interrupt service routine.

This is the common interrupt service routine for all enabled BMA250 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 BMA250 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 BMA250 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
argThe 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 bma250_init().

static bool bma250_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
sensorAddress of an initialized sensor device descriptor.
typeType of sensor data to read.
dataThe address where data values are returned.
Returns
bool true if the call succeeds, else false is returned.

References bma250_device_id(), bma250_get_accel(), bma250_get_temperature(), SENSOR_ERR_FUNCTION, SENSOR_READ_ACCELERATION, SENSOR_READ_ID, and SENSOR_READ_TEMPERATURE.

Referenced by bma250_init().

static bool bma250_selftest ( sensor_t sensor,
int *  test_code,
void *  arg 
)
static

Run BMA250 self-tests.

Parameters
sensorAddress of an initialized sensor device descriptor.
test_codeAddress of a device-specific numeric test code.
argDevice-specific self-test argument options.
Returns
bool true if the call succeeds, else false is returned.

References result, and SENSOR_TEST_DEFLECTION.

Referenced by bma250_init().

static bool bma250_set_bandwidth ( sensor_hal_t hal,
int16_t  band 
)
static

Set the BMA250 digital filter cut-off frequency.

Parameters
halAddress of an initialized sensor hardware descriptor.
bandThe index of a driver-specific bandwidth table entry.
Returns
bool true if the call succeeds, else false is returned.

References BMA250_BANDWIDTH, and sensor_bus_put.

Referenced by bma250_ioctl().

static bool bma250_set_range ( sensor_hal_t hal,
int16_t  range 
)
static

Set the BMA250 full scale acceleration range.

Parameters
halAddress of an initialized sensor hardware descriptor.
rangeThe index of a driver-specific range table entry.
Returns
bool true if the call succeeds, else false is returned.

References BMA250_G_RANGE, and sensor_bus_put.

Referenced by bma250_ioctl().

static bool bma250_set_state ( sensor_t sensor,
sensor_state_t  mode 
)
static

Set the BMA250 execution mode.

This routine sets a specified BMA250 execution state to one of the following:

SENSOR_STATE_SUSPEND or SENSOR_STATE_LOWEST_POWER The BMA250 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 BMA250 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:

  1. Wake-up
  2. Enable analog front-end and convert acceleration data until the low-pass filters have settled.
  3. 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.
  4. 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 BMA250, 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 BMA250 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
sensorAddress of a sensor device descriptor.
modeA specified sensor operational mode.
Returns
bool true if the call succeeds, else false is returned.

References BMA250_POWER_MODES, BMA250_RESET, bma250_sleep_en(), BMA250_SOFTRESET, BMA250_SUSPEND, 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 bma250_init(), and bma250_ioctl().

static bool bma250_set_tap ( sensor_hal_t hal,
sensor_tap_params_t params 
)
static

BMA250 tap detection configuration.

Parameters
halAddress of an initialized sensor hardware descriptor.
paramsAddress of an initialized tap parameter structure.
Returns
bool true if the call succeeds, else false is returned.

Referenced by bma250_ioctl().

static bool bma250_set_threshold ( sensor_hal_t hal,
sensor_threshold_desc_t threshold 
)
static

Set event threshold value.

Parameters
halAddress of an initialized sensor hardware descriptor.
thresholdAddress of threshold descriptor.
Returns
bool true if the call succeeds, else false is returned.

References BMA250_HIGH_G_THRESHOLD, BMA250_LOW_G_THRESHOLD, BMA250_SLOPE_THRESHOLD, BMA250_TAP_CONFIG, BMA250_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 bma250_ioctl().

static void bma250_sleep_en ( sensor_hal_t hal,
bool  sleep 
)
inlinestatic

Enable or disable the BMA250 sleep mode.

This routine enables or disables the BMA250 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
halAddress of an initialized sensor hardware descriptor.
sleepSet flag to enable sleep mode.
Returns
Nothing

References BMA250_LOWPOWER_EN, BMA250_POWER_MODES, BMA250_SLEEP_DUR_1ms, and sensor_bus_put.

Referenced by bma250_set_state().

bma_axis_t acc[3]

Acceleration data.

const sensor_map_t band_table[]
static
Initial value:
= {
}
#define BMA250_BANDWIDTH_1000Hz
Definition: bma250.h:201
#define BMA250_BANDWIDTH_125Hz
Definition: bma250.h:198
#define BMA250_BANDWIDTH_16Hz
Definition: bma250.h:195
#define BMA250_BANDWIDTH_250Hz
Definition: bma250.h:199
#define BMA250_BANDWIDTH_500Hz
Definition: bma250.h:200
#define BMA250_BANDWIDTH_31Hz
Definition: bma250.h:196
#define BMA250_BANDWIDTH_8Hz
Definition: bma250.h:194
#define BMA250_BANDWIDTH_63Hz
Definition: bma250.h:197

Bosch BMA250 Bandwidth Table (hertz, register value)

Referenced by bma250_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}
}
void default_event_handler(volatile sensor_event_data_t *data, volatile void *arg)
Default sensor event callback handler.
Definition: sensor.c:126

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

struct { ... } event_regs

Sensor Event Registers.

Referenced by bma250_get_accel(), and bma250_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}, BMA250_RANGE_2G},
{{ 4000}, BMA250_RANGE_4G},
{{ 8000}, BMA250_RANGE_8G},
{{16000}, BMA250_RANGE_16G}
}
#define BMA250_RANGE_8G
Definition: bma250.h:189
#define BMA250_RANGE_4G
Definition: bma250.h:188
#define BMA250_RANGE_16G
Definition: bma250.h:190
#define BMA250_RANGE_2G
Definition: bma250.h:187

Bosch BMA250 Range Table (milli-g, register value)

Referenced by bma250_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.