Atmel Software Framework

sfh7770.c File Reference

Osram SFH7770 light & proximity sensor driver.

This file contains functions for initializing and reading data from a Osram SFH7770 light & proximity sensor.

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

#include <string.h>
#include "sfh7770.h"

Data Structures

struct  current_level_t
 Proximity sensor LED current table (mA, register field value) More...
 
struct  sample_rate_t
 Sample rate table entry. More...
 

Macros

#define NUM_CURRENT_LEVELS   (sizeof(current_table) / sizeof(current_level_t))
 
#define NUM_LIGHT_RATES   (sizeof(light_rate_table) / sizeof(sample_rate_t))
 
#define NUM_PROX_RATES   (sizeof(prox_rate_table) / sizeof(sample_rate_t))
 
#define SFH7770_NVRAM_OFFSET   (0x18)
 

Functions

static bool sfh7770_calibrate (sensor_t *sensor, sensor_calibration_t calib_type, int step, void *info)
 Calibrate proximity sensor detection thresholds. More...
 
static bool sfh7770_device_id (sensor_hal_t *hal, sensor_data_t *data)
 Read SFH7770 device ID and revision numbers. More...
 
static bool sfh7770_event (sensor_t *sensor, sensor_event_t sensor_event, sensor_event_callback_t *callback, bool enable)
 Enable or disable SFH7770 sensor events. More...
 
static bool sfh7770_get_light (sensor_hal_t *hal, sensor_data_t *data)
 Read SFH7770 light level data. More...
 
static bool sfh7770_get_proximity (sensor_hal_t *hal, sensor_data_t *data)
 Read SFH7770 proximity data. More...
 
static bool sfh7770_get_threshold (sensor_hal_t *hal, int16_t channel, sensor_threshold_desc_t *threshold)
 Get event threshold value. More...
 
bool sfh7770_init (sensor_t *sensor, int resvd)
 Osram SFH7770 light & proximity sensor driver initialization. More...
 
static bool sfh7770_ioctl (sensor_t *sensor, sensor_command_t cmd, void *arg)
 SFH7770 ioctl control entry point. More...
 
static void sfh7770_isr (volatile void *arg)
 Osram SFH7770 driver interrupt service routine. More...
 
static bool sfh7770_read (sensor_t *sensor, sensor_read_t type, sensor_data_t *data)
 Read sensor data. More...
 
static bool sfh7770_set_current (sensor_hal_t *hal, int16_t channel, uint16_t *level_mA)
 Set proximity LED current level. More...
 
static bool sfh7770_set_rate (sensor_hal_t *hal, sensor_type_t type, uint16_t rate_hz)
 Set sensor sample rate. More...
 
static bool sfh7770_set_state (sensor_hal_t *hal, sensor_type_t type, sensor_state_t state)
 Set the SFH7770 execution mode. More...
 
static bool sfh7770_set_threshold (sensor_hal_t *hal, int16_t channel, sensor_threshold_desc_t *threshold)
 Set event threshold value. More...
 

Variables

static const current_level_t current_table []
 
static sensor_event_callback_t event_cb [3]
 Sensor Event Callback table (proximity=0, low light=1, high light=2) More...
 
static uint16_t high_light_threshold
 Event threshold value for hight light. More...
 
static const sample_rate_t light_rate_table []
 Light sensor sample rate table (Hz, reg field value) More...
 
static uint16_t low_light_threshold
 Event threshold value for low light. More...
 
static const sample_rate_t prox_rate_table []
 Proximity sensor sample rate table (Hz, reg field value) More...
 
static bool sfh7770_initialized = false
 Driver initialization flag. More...
 

#define NUM_CURRENT_LEVELS   (sizeof(current_table) / sizeof(current_level_t))

Referenced by sfh7770_set_current().

#define NUM_LIGHT_RATES   (sizeof(light_rate_table) / sizeof(sample_rate_t))

Referenced by sfh7770_set_rate().

#define NUM_PROX_RATES   (sizeof(prox_rate_table) / sizeof(sample_rate_t))

Referenced by sfh7770_set_rate().

#define SFH7770_NVRAM_OFFSET   (0x18)

static bool sfh7770_calibrate ( sensor_t sensor,
sensor_calibration_t  calib_type,
int  step,
void *  info 
)
static

Calibrate proximity sensor detection thresholds.

This function measures the proximity sensor output in 3 different steps, one for each channel in the device. This function should be called when a sample object has been placed at the desired distance from the device to define the threshold for near-proximity detection. The measured proximity sensor value for each channel is stored in non-volatile memory. These thresholds will later be used to set the threshold during the device initialization sequence.

This routine must be called 3 times total, with the "step" parameter indicating what stage of the calibration is being performed (i.e. which channel of the proximity sensor). This multi-step mechanism allows the application to prompt for physical placement of the object to be detected before this routine is called.

Parameters
sensorAddress of an initialized sensor device descriptor.
calib_typeThe address of a vector storing sensor axis data.
stepThe calibration stage number [1,3].
infoUnimplemented (ignored) parameter.
Returns
bool true if the call succeeds, else false is returned.

References MANUAL_CALIBRATE, nvram_read(), nvram_write(), prox_data, sensor_bus_get, sensor_bus_write, SENSOR_ERR_IO, SENSOR_ERR_PARAMS, SFH7770_NVRAM_OFFSET, SFH7770_PS_DATA_LED1, SFH7770_PS_DATA_LED2, SFH7770_PS_DATA_LED3, and SFH7770_PS_THR_LED1.

Referenced by sfh7770_init().

static bool sfh7770_device_id ( sensor_hal_t hal,
sensor_data_t data 
)
static

Read SFH7770 device ID and revision numbers.

This function reads the sensor 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 sensor_data_t::device, PART_ID_MASK, PART_ID_SHIFT, PART_REV_MASK, sensor_bus_get, and SFH7770_PART_ID.

Referenced by sfh7770_read().

static bool sfh7770_event ( sensor_t sensor,
sensor_event_t  sensor_event,
sensor_event_callback_t callback,
bool  enable 
)
static

Enable or disable SFH7770 sensor events.

Parameters
sensorAddress of an initialized sensor device descriptor
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 callback, INT_MODE_ALS, INT_MODE_PS, sensor_bus_get, sensor_bus_put, SENSOR_EVENT_HIGH_LIGHT, SENSOR_EVENT_LOW_LIGHT, SENSOR_EVENT_NEAR_PROXIMITY, SFH7770_INT_SET, and status.

Referenced by sfh7770_init(), and sfh7770_ioctl().

static bool sfh7770_get_light ( sensor_hal_t hal,
sensor_data_t data 
)
static

Read SFH7770 light level data.

This function reads the ambient light level data from the sensor and places it in the user-provided sensor_data_t structure.

Parameters
sensorAddress of an initialized sensor device descriptor.
dataThe address of a vector storing sensor measurement data.
Returns
bool true if the call succeeds, else false is returned.

References sensor_data_t::light, light_data, sensor_bus_read, and SFH7770_ALS_DATA_LSB.

Referenced by sfh7770_read().

static bool sfh7770_get_proximity ( sensor_hal_t hal,
sensor_data_t data 
)
static

Read SFH7770 proximity data.

This function reads the proximity data from the three channels of the sensor and places it in the user-provided sensor_data_t structure. The proximity value is not in standard units, so for "scaled" output the values are encoded based on whether or not the proximity reading exceeds the programmed threshold level for each channel (LED).

The sensor has only a single threshold level, so only two possible values are reported: PROXIMITY_NEAR (if threshold is exceeded) or PROXIMITY_NONE.

Parameters
sensorAddress of an initialized sensor device descriptor.
dataThe address of a vector storing sensor measurement data.
Returns
bool true if the call succeeds, else false is returned.

References sensor_data_t::proximity, PROXIMITY_NEAR, PROXIMITY_NONE, PS_LED1_THRESH, PS_LED2_THRESH, PS_LED3_THRESH, sensor_data_t::scaled, sensor_bus_read, and SFH7770_ALS_PS_STATUS.

Referenced by sfh7770_read().

static bool sfh7770_get_threshold ( sensor_hal_t hal,
int16_t  channel,
sensor_threshold_desc_t threshold 
)
static

Get event threshold value.

Parameters
halAddress of an initialized sensor hardware descriptor.
channelChannel (LED) number to set threshold
thresholdAddress of threshold descriptor.
Returns
bool true if the call succeeds, else false is returned.

References high_light_threshold, low_light_threshold, result, sensor_bus_get, SENSOR_CHANNEL_ALL, SENSOR_THRESHOLD_HIGH_LIGHT, SENSOR_THRESHOLD_LOW_LIGHT, SENSOR_THRESHOLD_NEAR_PROXIMITY, SFH7770_PS_THR_LED1, sensor_threshold_desc_t::type, and sensor_threshold_desc_t::value.

Referenced by sfh7770_ioctl().

static bool sfh7770_ioctl ( sensor_t sensor,
sensor_command_t  cmd,
void *  arg 
)
static

SFH7770 ioctl control entry point.

Parameters
halAddress of an initialized sensor hardware descriptor.
cmdCommand to execute
argArgument for command (varies)
Returns
bool true if the call succeeds, else false is returned.

References SENSOR_DISABLE_EVENT, SENSOR_ENABLE_EVENT, SENSOR_ERR_UNSUPPORTED, SENSOR_GET_THRESHOLD, SENSOR_SET_CURRENT, SENSOR_SET_SAMPLE_RATE, SENSOR_SET_STATE, SENSOR_SET_THRESHOLD, sfh7770_event(), sfh7770_get_threshold(), sfh7770_set_current(), sfh7770_set_rate(), sfh7770_set_state(), sfh7770_set_threshold(), and status.

Referenced by sfh7770_init().

static void sfh7770_isr ( volatile void *  arg)
static

Osram SFH7770 driver interrupt service routine.

This is the common interrupt service routine for all enabled SFH7770 interrupt events. Three different types of interrupts can be programmed: high light level, low light level, and near proximity. All share the same interrupt pin and therefore the same ISR entry.

Parameters
argThe address of the driver sensor_hal_t descriptor.
Returns
Nothing.

References sensor_hal::burst_addr, sensor_hal::bus, sensor_event_data_t::channel, sensor_event_data_t::data, sensor_event_data_t::event, sensor_event_callback_t::handler, high_light_threshold, INT_SOURCE_ALS, INT_SOURCE_LED1, INT_SOURCE_LED2, INT_SOURCE_LED3, INT_SOURCE_MASK, sensor_data_t::light, low_light_threshold, bus_desc_t::no_wait, sensor_data_t::proximity, PROXIMITY_NEAR, PROXIMITY_NONE, PS_LED1_THRESH, PS_LED2_THRESH, PS_LED3_THRESH, sensor_data_t::scaled, sensor_bus_read, SENSOR_EVENT_HIGH_LIGHT, SENSOR_EVENT_LOW_LIGHT, SENSOR_EVENT_NEAR_PROXIMITY, SENSOR_EVENT_UNKNOWN, sensor_timestamp(), bus_desc_t::status, STATUS_OK, and sensor_data_t::timestamp.

Referenced by sfh7770_init().

static bool sfh7770_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 SENSOR_ERR_FUNCTION, SENSOR_READ_ID, SENSOR_READ_LIGHT, SENSOR_READ_PROXIMITY, sfh7770_device_id(), sfh7770_get_light(), and sfh7770_get_proximity().

Referenced by sfh7770_init().

static bool sfh7770_set_current ( sensor_hal_t hal,
int16_t  channel,
uint16_t *  level_mA 
)
static

Set proximity LED current level.

Parameters
halAddress of an initialized sensor hardware descriptor.
channelChannel (LED) number to set current
curr_levelsAddress of an array of current levels (1 per LED)
Returns
bool true if the call succeeds, else false is returned.

References current_level_t::field_val, I_LED1_MASK, I_LED2_MASK, I_LED2_SHIFT, NUM_CURRENT_LEVELS, sensor_bus_get, sensor_bus_put, SENSOR_CHANNEL_ALL, SFH7770_I_LED_1_2, SFH7770_I_LED_3, and status.

Referenced by sfh7770_ioctl().

static bool sfh7770_set_rate ( sensor_hal_t hal,
sensor_type_t  type,
uint16_t  rate_hz 
)
static

Set sensor sample rate.

Parameters
halAddress of an initialized sensor hardware descriptor.
typeActive mode of the sensor (i.e. light or proximity)
rate_hzSample rate in Hz
Returns
bool true if the call succeeds, else false is returned.

References NUM_LIGHT_RATES, NUM_PROX_RATES, sensor_bus_put, SENSOR_TYPE_LIGHT, SENSOR_TYPE_PROXIMITY, SFH7770_ALS_INTERVAL, SFH7770_PS_INTERVAL, and status.

Referenced by sfh7770_ioctl().

static bool sfh7770_set_state ( sensor_hal_t hal,
sensor_type_t  type,
sensor_state_t  state 
)
static

Set the SFH7770 execution mode.

This routine sets a specified SFH7770 execution state to one of the following:

SENSOR_STATE_SLEEP: Setting the sleep mode puts the specific sensor unit (light or proximity) in standby mode, in which no measurements are made.

SENSOR_STATE_NORMAL: Setting the sleep mode puts the specific sensor unit (light or proximity) in continuous measurement mode.

Parameters
halAddress of an initialized sensor hardware descriptor.
typeThe operational type of the sensor (light or proximity)
stateA specified sensor operational state.
Returns
bool true if the call succeeds, else false is returned.

References ALS_MODE_FREE_RUNNING, ALS_MODE_STANDBY, PS_MODE_FREE_RUNNING, PS_MODE_STANDBY, sensor_bus_put, SENSOR_STATE_NORMAL, SENSOR_STATE_SLEEP, SENSOR_TYPE_LIGHT, SFH7770_ALS_CONTROL, and SFH7770_PS_CONTROL.

Referenced by sfh7770_ioctl().

static bool sfh7770_set_threshold ( sensor_hal_t hal,
int16_t  channel,
sensor_threshold_desc_t threshold 
)
static

Set event threshold value.

Parameters
halAddress of an initialized sensor hardware descriptor.
channelChannel (LED) number to set threshold
thresholdAddress of threshold descriptor.
Returns
bool true if the call succeeds, else false is returned.

References high_light_threshold, if(), low_light_threshold, nvram_write(), result, sensor_bus_put, sensor_bus_write, SENSOR_CHANNEL_ALL, SENSOR_THRESHOLD_HIGH_LIGHT, SENSOR_THRESHOLD_LOW_LIGHT, SENSOR_THRESHOLD_NEAR_PROXIMITY, SFH7770_ALS_LO_THR_LSB, SFH7770_ALS_UP_THR_LSB, SFH7770_NVRAM_OFFSET, SFH7770_PS_THR_LED1, sensor_threshold_desc_t::type, and sensor_threshold_desc_t::value.

Referenced by sfh7770_ioctl().

const current_level_t current_table[]
static
Initial value:
= {
{ 5, I_LED_5MA }, { 10, I_LED_10MA },
{ 20, I_LED_20MA }, { 50, I_LED_50MA },
{100, I_LED_100MA}, {150, I_LED_150MA},
{200, I_LED_200MA}
}
#define I_LED_200MA
Definition: sfh7770.h:121
#define I_LED_5MA
Definition: sfh7770.h:115
#define I_LED_100MA
Definition: sfh7770.h:119
#define I_LED_150MA
Definition: sfh7770.h:120
#define I_LED_10MA
Definition: sfh7770.h:116
#define I_LED_20MA
Definition: sfh7770.h:117
#define I_LED_50MA
Definition: sfh7770.h:118
sensor_event_callback_t event_cb[3]
static
Initial value:
= {
{.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 table (proximity=0, low light=1, high light=2)

uint16_t high_light_threshold
static

Event threshold value for hight light.

Referenced by sfh7770_get_threshold(), sfh7770_isr(), and sfh7770_set_threshold().

const sample_rate_t light_rate_table[]
static
Initial value:
= {
}
#define ALS_INTERVAL_100MS
Definition: sfh7770.h:172
#define ALS_INTERVAL_200MS
Definition: sfh7770.h:173
#define ALS_INTERVAL_1000MS
Definition: sfh7770.h:175
#define ALS_INTERVAL_500MS
Definition: sfh7770.h:174
#define ALS_INTERVAL_2000MS
Definition: sfh7770.h:176

Light sensor sample rate table (Hz, reg field value)

uint16_t low_light_threshold
static

Event threshold value for low light.

Referenced by sfh7770_get_threshold(), sfh7770_isr(), and sfh7770_set_threshold().

const sample_rate_t prox_rate_table[]
static
Initial value:
= {
{ 14, PS_INTERVAL_70MS },
{ 20, PS_INTERVAL_50MS },
{ 33, PS_INTERVAL_30MS },
{ 50, PS_INTERVAL_20MS },
}
#define PS_INTERVAL_100MS
Definition: sfh7770.h:164
#define PS_INTERVAL_70MS
Definition: sfh7770.h:163
#define PS_INTERVAL_30MS
Definition: sfh7770.h:161
#define PS_INTERVAL_20MS
Definition: sfh7770.h:160
#define PS_INTERVAL_200MS
Definition: sfh7770.h:165
#define PS_INTERVAL_2000MS
Definition: sfh7770.h:168
#define PS_INTERVAL_10MS
Definition: sfh7770.h:159
#define PS_INTERVAL_1000MS
Definition: sfh7770.h:167
#define PS_INTERVAL_50MS
Definition: sfh7770.h:162
#define PS_INTERVAL_500MS
Definition: sfh7770.h:166

Proximity sensor sample rate table (Hz, reg field value)

bool sfh7770_initialized = false
static

Driver initialization flag.

Referenced by sfh7770_init().