332 lines
12 KiB
C
332 lines
12 KiB
C
/**************************************************************************/
|
|
/*!
|
|
@file tsl2561.c
|
|
@author K. Townsend (microBuilder.eu)
|
|
|
|
@brief Drivers for the TAOS TSL2561 I2C digital luminosity sensor
|
|
|
|
@section DESCRIPTION
|
|
|
|
The TSL2561 is a 16-bit digital luminosity sensor the approximates
|
|
the human eye's response to light. It contains one broadband
|
|
photodiode that measures visible plus infrared light (channel 0)
|
|
and one infrared photodiode (channel 1).
|
|
|
|
@section EXAMPLE
|
|
|
|
@code
|
|
#include "drivers/sensors/tsl2561/tsl2561.h"
|
|
...
|
|
uint16_t broadband, ir;
|
|
uint32_t lux;
|
|
|
|
// Initialise luminosity sensor
|
|
tsl2561Init();
|
|
|
|
// Optional ... default setting is 400ms with no gain
|
|
// Set timing to 101ms with no gain
|
|
tsl2561SetTiming(TSL2561_INTEGRATIONTIME_101MS, TSL2561_GAIN_0X);
|
|
|
|
// Check luminosity level and calculate lux
|
|
tsl2561GetLuminosity(&broadband, &ir);
|
|
lux = tsl2561CalculateLux(broadband, ir);
|
|
printf("Broadband: %u, IR: %u, Lux: %d %s", broadband, ir, lux, CFG_PRINTF_NEWLINE);
|
|
|
|
@endcode
|
|
|
|
@section LICENSE
|
|
|
|
Software License Agreement (BSD License)
|
|
|
|
Copyright (c) 2010, microBuilder SARL
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
1. Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
2. Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
3. Neither the name of the copyright holders nor the
|
|
names of its contributors may be used to endorse or promote products
|
|
derived from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
|
|
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
|
|
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
/**************************************************************************/
|
|
#include "tsl2561.h"
|
|
static const uint32_t tsl2561_i2c_id = 0;
|
|
static bool _tsl2561Initialised = 0;
|
|
static tsl2561IntegrationTime_t _tsl2561IntegrationTime = TSL2561_INTEGRATIONTIME_402MS;
|
|
static tsl2561Gain_t _tsl2561Gain = TSL2561_GAIN_0X;
|
|
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Writes an 8 bit values over I2C
|
|
*/
|
|
/**************************************************************************/
|
|
tsl2561Error_t tsl2561Write8 (uint8_t reg, uint8_t value)
|
|
{
|
|
platform_i2c_send_start(tsl2561_i2c_id);
|
|
platform_i2c_send_address(tsl2561_i2c_id, TSL2561_ADDRESS, PLATFORM_I2C_DIRECTION_TRANSMITTER);
|
|
platform_i2c_send_byte(tsl2561_i2c_id, reg);
|
|
platform_i2c_send_byte(tsl2561_i2c_id, value);
|
|
platform_i2c_send_stop(tsl2561_i2c_id);
|
|
return TSL2561_ERROR_OK;
|
|
}
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Reads a 16 bit values over I2C
|
|
*/
|
|
/**************************************************************************/
|
|
tsl2561Error_t tsl2561Read16(uint8_t reg, uint16_t *value)
|
|
{
|
|
platform_i2c_send_start(tsl2561_i2c_id);
|
|
platform_i2c_send_address(tsl2561_i2c_id, TSL2561_ADDRESS, PLATFORM_I2C_DIRECTION_TRANSMITTER);
|
|
platform_i2c_send_byte(tsl2561_i2c_id, reg);
|
|
platform_i2c_send_stop(tsl2561_i2c_id);
|
|
platform_i2c_send_start(tsl2561_i2c_id);
|
|
platform_i2c_send_address(tsl2561_i2c_id, TSL2561_ADDRESS, PLATFORM_I2C_DIRECTION_RECEIVER);
|
|
uint8_t ch_high = platform_i2c_recv_byte(tsl2561_i2c_id, 0);
|
|
platform_i2c_send_stop(tsl2561_i2c_id);
|
|
|
|
platform_i2c_send_start(tsl2561_i2c_id);
|
|
platform_i2c_send_address(tsl2561_i2c_id, TSL2561_ADDRESS, PLATFORM_I2C_DIRECTION_TRANSMITTER);
|
|
platform_i2c_send_byte(tsl2561_i2c_id, reg);
|
|
platform_i2c_send_stop(tsl2561_i2c_id);
|
|
platform_i2c_send_start(tsl2561_i2c_id);
|
|
platform_i2c_send_address(tsl2561_i2c_id, TSL2561_ADDRESS, PLATFORM_I2C_DIRECTION_RECEIVER);
|
|
uint8_t ch_low = platform_i2c_recv_byte(tsl2561_i2c_id, 0);
|
|
platform_i2c_send_stop(tsl2561_i2c_id);
|
|
|
|
// Shift values to create properly formed integer (low byte first)
|
|
*value = (ch_low | (ch_high << 8));
|
|
|
|
return TSL2561_ERROR_OK;
|
|
}
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Enables the device
|
|
*/
|
|
/**************************************************************************/
|
|
tsl2561Error_t tsl2561Enable(void)
|
|
{
|
|
if (!_tsl2561Initialised) tsl2561Init();
|
|
|
|
// Enable the device by setting the control bit to 0x03
|
|
return tsl2561Write8(TSL2561_COMMAND_BIT | TSL2561_REGISTER_CONTROL, TSL2561_CONTROL_POWERON);
|
|
}
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Disables the device (putting it in lower power sleep mode)
|
|
*/
|
|
/**************************************************************************/
|
|
tsl2561Error_t tsl2561Disable(void)
|
|
{
|
|
if (!_tsl2561Initialised) tsl2561Init();
|
|
|
|
// Turn the device off to save power
|
|
return tsl2561Write8(TSL2561_COMMAND_BIT | TSL2561_REGISTER_CONTROL, TSL2561_CONTROL_POWEROFF);
|
|
}
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Initialises the I2C block
|
|
*/
|
|
/**************************************************************************/
|
|
tsl2561Error_t tsl2561Init(uint8_t sda, uint8_t scl)
|
|
{
|
|
// Initialise I2C
|
|
platform_i2c_setup(tsl2561_i2c_id, sda, scl, PLATFORM_I2C_SPEED_SLOW);
|
|
|
|
_tsl2561Initialised = 1;
|
|
|
|
// Set default integration time and gain
|
|
tsl2561SetTiming(_tsl2561IntegrationTime, _tsl2561Gain);
|
|
|
|
// Note: by default, the device is in power down mode on bootup
|
|
|
|
return TSL2561_ERROR_OK;
|
|
}
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Sets the integration time and gain (controls sensitivity)
|
|
*/
|
|
/**************************************************************************/
|
|
tsl2561Error_t tsl2561SetTiming(tsl2561IntegrationTime_t integration, tsl2561Gain_t gain)
|
|
{
|
|
if (!_tsl2561Initialised) tsl2561Init();
|
|
|
|
tsl2561Error_t error = TSL2561_ERROR_OK;
|
|
|
|
// Enable the device by setting the control bit to 0x03
|
|
error = tsl2561Enable();
|
|
if (error) return error;
|
|
|
|
// Turn the device off to save power
|
|
error = tsl2561Write8(TSL2561_COMMAND_BIT | TSL2561_REGISTER_TIMING, integration | gain);
|
|
if (error) return error;
|
|
|
|
// Update value placeholders
|
|
_tsl2561IntegrationTime = integration;
|
|
_tsl2561Gain = gain;
|
|
|
|
// Turn the device off to save power
|
|
error = tsl2561Disable();
|
|
if (error) return error;
|
|
|
|
return error;
|
|
}
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Reads the luminosity on both channels from the TSL2561
|
|
*/
|
|
/**************************************************************************/
|
|
tsl2561Error_t tsl2561GetLuminosity (uint16_t *broadband, uint16_t *ir)
|
|
{
|
|
if (!_tsl2561Initialised) tsl2561Init();
|
|
|
|
tsl2561Error_t error = TSL2561_ERROR_OK;
|
|
|
|
// Enable the device by setting the control bit to 0x03
|
|
error = tsl2561Enable();
|
|
if (error) return error;
|
|
|
|
// Wait x ms for ADC to complete
|
|
switch (_tsl2561IntegrationTime)
|
|
{
|
|
case TSL2561_INTEGRATIONTIME_13MS:
|
|
systickDelay(14);
|
|
break;
|
|
case TSL2561_INTEGRATIONTIME_101MS:
|
|
systickDelay(102);
|
|
break;
|
|
default:
|
|
systickDelay(400);
|
|
break;
|
|
}
|
|
|
|
// Reads two byte value from channel 0 (visible + infrared)
|
|
error = tsl2561Read16(TSL2561_COMMAND_BIT | TSL2561_WORD_BIT | TSL2561_REGISTER_CHAN0_LOW, broadband);
|
|
if (error) return error;
|
|
|
|
// Reads two byte value from channel 1 (infrared)
|
|
error = tsl2561Read16(TSL2561_COMMAND_BIT | TSL2561_WORD_BIT | TSL2561_REGISTER_CHAN1_LOW, ir);
|
|
if (error) return error;
|
|
|
|
// Turn the device off to save power
|
|
error = tsl2561Disable();
|
|
if (error) return error;
|
|
|
|
return error;
|
|
}
|
|
|
|
/**************************************************************************/
|
|
/*!
|
|
@brief Calculates LUX from the supplied ch0 (broadband) and ch1
|
|
(IR) readings
|
|
*/
|
|
/**************************************************************************/
|
|
uint32_t tsl2561CalculateLux(uint16_t ch0, uint16_t ch1)
|
|
{
|
|
unsigned long chScale;
|
|
unsigned long channel1;
|
|
unsigned long channel0;
|
|
|
|
switch (_tsl2561IntegrationTime)
|
|
{
|
|
case TSL2561_INTEGRATIONTIME_13MS:
|
|
chScale = TSL2561_LUX_CHSCALE_TINT0;
|
|
break;
|
|
case TSL2561_INTEGRATIONTIME_101MS:
|
|
chScale = TSL2561_LUX_CHSCALE_TINT1;
|
|
break;
|
|
default: // No scaling ... integration time = 402ms
|
|
chScale = (1 << TSL2561_LUX_CHSCALE);
|
|
break;
|
|
}
|
|
|
|
// Scale for gain (1x or 16x)
|
|
if (!_tsl2561Gain) chScale = chScale << 4;
|
|
|
|
// scale the channel values
|
|
channel0 = (ch0 * chScale) >> TSL2561_LUX_CHSCALE;
|
|
channel1 = (ch1 * chScale) >> TSL2561_LUX_CHSCALE;
|
|
|
|
// find the ratio of the channel values (Channel1/Channel0)
|
|
unsigned long ratio1 = 0;
|
|
if (channel0 != 0) ratio1 = (channel1 << (TSL2561_LUX_RATIOSCALE+1)) / channel0;
|
|
|
|
// round the ratio value
|
|
unsigned long ratio = (ratio1 + 1) >> 1;
|
|
|
|
unsigned int b, m;
|
|
|
|
#ifdef TSL2561_PACKAGE_CS
|
|
if ((ratio >= 0) && (ratio <= TSL2561_LUX_K1C))
|
|
{b=TSL2561_LUX_B1C; m=TSL2561_LUX_M1C;}
|
|
else if (ratio <= TSL2561_LUX_K2C)
|
|
{b=TSL2561_LUX_B2C; m=TSL2561_LUX_M2C;}
|
|
else if (ratio <= TSL2561_LUX_K3C)
|
|
{b=TSL2561_LUX_B3C; m=TSL2561_LUX_M3C;}
|
|
else if (ratio <= TSL2561_LUX_K4C)
|
|
{b=TSL2561_LUX_B4C; m=TSL2561_LUX_M4C;}
|
|
else if (ratio <= TSL2561_LUX_K5C)
|
|
{b=TSL2561_LUX_B5C; m=TSL2561_LUX_M5C;}
|
|
else if (ratio <= TSL2561_LUX_K6C)
|
|
{b=TSL2561_LUX_B6C; m=TSL2561_LUX_M6C;}
|
|
else if (ratio <= TSL2561_LUX_K7C)
|
|
{b=TSL2561_LUX_B7C; m=TSL2561_LUX_M7C;}
|
|
else if (ratio > TSL2561_LUX_K8C)
|
|
{b=TSL2561_LUX_B8C; m=TSL2561_LUX_M8C;}
|
|
#else
|
|
if ((ratio >= 0) && (ratio <= TSL2561_LUX_K1T))
|
|
{b=TSL2561_LUX_B1T; m=TSL2561_LUX_M1T;}
|
|
else if (ratio <= TSL2561_LUX_K2T)
|
|
{b=TSL2561_LUX_B2T; m=TSL2561_LUX_M2T;}
|
|
else if (ratio <= TSL2561_LUX_K3T)
|
|
{b=TSL2561_LUX_B3T; m=TSL2561_LUX_M3T;}
|
|
else if (ratio <= TSL2561_LUX_K4T)
|
|
{b=TSL2561_LUX_B4T; m=TSL2561_LUX_M4T;}
|
|
else if (ratio <= TSL2561_LUX_K5T)
|
|
{b=TSL2561_LUX_B5T; m=TSL2561_LUX_M5T;}
|
|
else if (ratio <= TSL2561_LUX_K6T)
|
|
{b=TSL2561_LUX_B6T; m=TSL2561_LUX_M6T;}
|
|
else if (ratio <= TSL2561_LUX_K7T)
|
|
{b=TSL2561_LUX_B7T; m=TSL2561_LUX_M7T;}
|
|
else if (ratio > TSL2561_LUX_K8T)
|
|
{b=TSL2561_LUX_B8T; m=TSL2561_LUX_M8T;}
|
|
#endif
|
|
|
|
unsigned long temp;
|
|
temp = ((channel0 * b) - (channel1 * m));
|
|
|
|
// do not allow negative lux value
|
|
if (temp < 0) temp = 0;
|
|
|
|
// round lsb (2^(LUX_SCALE-1))
|
|
temp += (1 << (TSL2561_LUX_LUXSCALE-1));
|
|
|
|
// strip off fractional portion
|
|
uint32_t lux = temp >> TSL2561_LUX_LUXSCALE;
|
|
|
|
// Signal I2C had no errors
|
|
return lux;
|
|
}
|