upm  1.7.1
Sensor/Actuator repository for libmraa (v2.0.0)
Data Structures | Functions | Typedefs
light.h File Reference
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API Description

/*
* Author: Noel Eck <noel.eck@intel.com>
* Copyright (c) 2016 Intel Corporation.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <unistd.h>
#include <signal.h>
#include "light.h"
#include "upm_utilities.h"
bool shouldRun = true;
void sig_handler(int signo)
{
if (signo == SIGINT)
shouldRun = false;
}
int main()
{
signal(SIGINT, sig_handler);
// Instantiate a light sensor on analog pin A0
if (!sensor)
{
printf("light_init() failed.\n");
return -1;
}
// Set the aref, scale, and offset
light_set_aref(sensor, 5.0);
light_set_scale(sensor, 1.0);
light_set_offset(sensor, -.1);
printf("aRef: %0.03f scale: %0.03f offset: %0.03f\n\n",
light_get_aref(sensor),
light_get_scale(sensor),
light_get_offset(sensor));
// Every half a second, sample the sensor output
while (shouldRun)
{
float normalized = 0.0;
float raw_volts = 0.0;
float lux = 0.0;
light_get_normalized(sensor, &normalized);
light_get_raw_volts(sensor, &raw_volts);
light_get_lux(sensor, &lux);
printf("Normalized output: %0.03f, raw light sensor output: %0.03f v "
"light output: %0.03f lux\n", normalized, raw_volts, lux);
upm_delay_ms(500);
}
printf("Exiting\n");
light_close(sensor);
return 0;
}

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Data Structures

struct  _light_context
 

Functions

light_context light_init (int16_t pin)
 
void light_close (light_context dev)
 
upm_result_t light_set_aref (const light_context dev, float aref)
 
upm_result_t light_set_scale (const light_context dev, float scale)
 
upm_result_t light_set_offset (const light_context dev, float offset)
 
float light_get_aref (const light_context dev)
 
float light_get_scale (const light_context dev)
 
float light_get_offset (const light_context dev)
 
upm_result_t light_get_normalized (const light_context dev, float *value)
 
upm_result_t light_get_raw_volts (const light_context dev, float *value)
 
upm_result_t light_get_lux (const light_context dev, float *value)
 

Typedefs

typedef struct _light_contextlight_context
 

Function Documentation

light_context light_init ( int16_t  pin)

Initialize analog sensor

Parameters
pinAnalog pin
Returns
sensor context
void light_close ( light_context  dev)

Analog sensor destructor

Parameters
sensorcontext pointer

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upm_result_t light_set_aref ( const light_context  dev,
float  aref 
)

Set ADC reference voltage

Parameters
devsensor context pointer
arefADC reference voltage
Returns
Function result code

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upm_result_t light_set_scale ( const light_context  dev,
float  scale 
)

Set sensor scale. This scale is applied to the return value: counts = counts * scale

Parameters
devsensor context pointer
scalecount scale value used
Returns
Function result code

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upm_result_t light_set_offset ( const light_context  dev,
float  offset 
)

Set sensor offset. This offset is applied to the return value: value = value + offset

Parameters
devsensor context pointer
offsetcount offset value used
Returns
Function result code
float light_get_aref ( const light_context  dev)

Get sensor aref

Parameters
devsensor context pointer
Returns
Sensor ADC reference voltage

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float light_get_scale ( const light_context  dev)

Get sensor scale

Parameters
devsensor context pointer
Returns
Sensor scale

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float light_get_offset ( const light_context  dev)

Get sensor offset

Parameters
devsensor context pointer
Returns
Sensor offset

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upm_result_t light_get_normalized ( const light_context  dev,
float *  value 
)

Read normalized value for sensor

Parameters
devsensor context pointer
*valueNormalized value (0.0 -> 1.0)
Returns
Function result code

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upm_result_t light_get_raw_volts ( const light_context  dev,
float *  value 
)

Read raw voltage from the sensor

Parameters
devsensor context pointer
*valueRaw sensor voltage
Returns
Function result code

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upm_result_t light_get_lux ( const light_context  dev,
float *  value 
)

Read scaled/offset light value in lux

Parameters
devsensor context pointer
*valueAdjusted sensor value in lux
Returns
Function result code

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Typedef Documentation

typedef struct _light_context * light_context

driver context