Utilities for UnitColor. More...

#include "../unit/unit_TCS3472x_data.hpp"
#include <algorithm>
#include <cmath>
#include <tuple>
#include <cassert>
#include <type_traits>

Classes
struct	m5::unit::tcs3472x::Calibration
	Raw value to determine black and white. More...

Namespaces
namespace	m5
	Top level namespace of M5Stack.

Functions
float	m5::unit::tcs3472x::atime_to_ms (const uint8_t a)
	ATIME to ms.

float	m5::unit::tcs3472x::wtime_to_ms (const uint8_t w, const bool wlong)
	WTIME and WLONG to ms.

uint8_t	m5::unit::tcs3472x::ms_to_atime (const float ms)
	ms to ATIME

std::tuple< uint8_t, bool >	m5::unit::tcs3472x::ms_to_wtime (const float ms)
	ms to WTIME and WLONG

float	m5::unit::tcs3472x::calculateLux (const uint16_t rawR, const uint16_t rawG, const uint16_t rawB, const uint16_t rawC, const float atime_ms, const Gain gc, const float dgf=DGF, const float coefR=R_Coef, const float coefG=G_Coef, const float coefB=B_Coef)
	Calculate Lux.

float	m5::unit::tcs3472x::calculateColorTemperature (const uint16_t rawR, const uint16_t rawG, const uint16_t rawB, const uint16_t rawC, const float coefCT=CT_Coef, const float offsetCT=CT_Offset)
	Calculate color temperature(degrees Kelvin)

uint16_t	m5::unit::tcs3472x::calculateSaturation (const uint8_t atime)
	Calculate Saturation.

uint16_t	m5::unit::tcs3472x::calculateSaturation (const float atime_ms)
	Calculate Saturation.

template<typename T , typename std::enable_if< std::is_integral< T >::value &&!std::is_same< T, uint8_t >::value, std::nullptr_t >::type = nullptr>
uint16_t	m5::unit::tcs3472x::calculateSaturation (const T atime)
	Calculate Saturation.

float	m5::unit::tcs3472x::calculateCRATIO (const uint16_t rawR, const uint16_t rawG, const uint16_t rawB, const uint16_t rawC)
	Calculate CRATIO.

float	m5::unit::tcs3472x::calculateCPL (const float atime_ms, const Gain gc, const float dgf=DGF)
	Calculate Counts per Lux (CPL)

float	m5::unit::tcs3472x::calculateMaxLux (const float atime_ms, const Gain gc, const float dgf=DGF)
	Calculate maximum Lux.

template<size_t Size = 256>
M5_UNIT_COLOR_UTILITY_UNIT_COLOR_UTILITY_CONSTEXPR std::array< uint8_t, Size >	m5::unit::tcs3472x::make_gamma_table (const float gamma=2.2f)
	Make gamma table.

Variables
Coefficients for Lux and CT Equations
constexpr float	m5::unit::tcs3472x::GA {1.0f}
	Glass attenuation factor (open air)

constexpr float	m5::unit::tcs3472x::DF {310.f}
	Device factor.

constexpr float	m5::unit::tcs3472x::DGF {GA * DF}
	Device and glass factor.

constexpr float	m5::unit::tcs3472x::R_Coef {0.136f}
	Lux coefficient for the red channel.

constexpr float	m5::unit::tcs3472x::G_Coef {1.0f}
	Lux coefficient for the green channel.

constexpr float	m5::unit::tcs3472x::B_Coef {-0.444f}
	Lux coefficient for the blue channel.

constexpr float	m5::unit::tcs3472x::CT_Coef {3810.f}
	Color temperature coefficient.

constexpr float	m5::unit::tcs3472x::CT_Offset {1391.f}
	Color temperature offset.

For A/WTIME
constexpr float	m5::unit::tcs3472x::AT_NORMAL_FACTOR {2.4f}
	ATIME step (ms)

constexpr float	m5::unit::tcs3472x::AT_NORMAL_MIN {AT_NORMAL_FACTOR}
	Minimum ATIME (2.4 ms)

constexpr float	m5::unit::tcs3472x::AT_NORMAL_MAX {256 * AT_NORMAL_FACTOR}
	Maximum ATIME (614.4 ms)

constexpr float	m5::unit::tcs3472x::WT_NORMAL_FACTOR {AT_NORMAL_FACTOR}
	WTIME step (ms)

constexpr float	m5::unit::tcs3472x::WT_NORMAL_MIN {WT_NORMAL_FACTOR}
	Minimum WTIME (2.4 ms)

constexpr float	m5::unit::tcs3472x::WT_NORMAL_MAX {256 * WT_NORMAL_FACTOR}
	Maximum WTIME without WLONG (614.4 ms)

constexpr float	m5::unit::tcs3472x::WT_LONG_FACTOR {2.4f * 12.f}
	WTIME step with WLONG (ms)

constexpr float	m5::unit::tcs3472x::WT_LONG_MIN {WT_LONG_FACTOR}
	Minimum WTIME with WLONG (28.8 ms)

constexpr float	m5::unit::tcs3472x::WT_LONG_MAX {256 * WT_LONG_FACTOR}
	Maximum WTIME with WLONG (7372.8 ms)

Detailed Description

Utilities for UnitColor.

Function Documentation

◆ atime_to_ms()

float m5::unit::tcs3472x::atime_to_ms ( const uint8_t a )

inline

ATIME to ms.

Parameters

a	ATIME raw value

Returns: Integration time (ms)

◆ calculateColorTemperature()

float m5::unit::tcs3472x::calculateColorTemperature	(	const uint16_t	rawR,
		const uint16_t	rawG,
		const uint16_t	rawB,
		const uint16_t	rawC,
		const float	coefCT = CT_Coef,
		const float	offsetCT = CT_Offset )

Calculate color temperature(degrees Kelvin)

Parameters

rawR	Raw red value
rawG	Raw green value
rawB	Raw blue value
rawC	Raw clear value
coefCT	Coefficient for the color temperature
offsetCT	Offset for the color temperature

Returns: Color temperature(degrees Kelvin)

◆ calculateCPL()

float m5::unit::tcs3472x::calculateCPL	(	const float	atime_ms,
		const Gain	gc,
		const float	dgf = DGF )

Calculate Counts per Lux (CPL)

Parameters

atime_ms	integration time(ms)
gc	Gain
dgf	Device and Glass Factor

Returns: CPL

◆ calculateCRATIO()

float m5::unit::tcs3472x::calculateCRATIO	(	const uint16_t	rawR,
		const uint16_t	rawG,
		const uint16_t	rawB,
		const uint16_t	rawC )

Calculate CRATIO.

Parameters

rawR	raw red value
rawG	raw green value
rawB	raw blue value
rawC	raw clear value

Returns: CRATIO (0.0f - 1.0f)

Guidelines for CRATIO and Light Source Correspondence

Compare	Description
CRATIO < 0.1	LED or fluorescent light
0.1 <= CRATIO < 0.25	Sunlight
0.25 <= CRATIO	Incandescent light

◆ calculateLux()

float m5::unit::tcs3472x::calculateLux	(	const uint16_t	rawR,
		const uint16_t	rawG,
		const uint16_t	rawB,
		const uint16_t	rawC,
		const float	atime_ms,
		const Gain	gc,
		const float	dgf = DGF,
		const float	coefR = R_Coef,
		const float	coefG = G_Coef,
		const float	coefB = B_Coef )

Calculate Lux.

Parameters

rawR	Raw red value
rawG	Raw green value
rawB	Raw blue value
rawC	Raw clear value
atime_ms	Integration time(ms)
gc	Gain
dgf	Device and Glass Factor
coefR	Coefficient for the R channel
coefG	Coefficient for the G channel
coefB	Coefficient for the B channel

Returns: Lux (lx)

◆ calculateMaxLux()

float m5::unit::tcs3472x::calculateMaxLux	(	const float	atime_ms,
		const Gain	gc,
		const float	dgf = DGF )

inline

Calculate maximum Lux.

Parameters

atime_ms	integration time(ms)
gc	Gain
dgf	Device and Glass Factor

Returns: Lux(lx)

◆ calculateSaturation() [1/3]

uint16_t m5::unit::tcs3472x::calculateSaturation ( const float atime_ms )

inline

Calculate Saturation.

Parameters

atime_ms ATIME ms value

Returns: Saturation value

Note: Ripple saturation is also considered (in Analog)

◆ calculateSaturation() [2/3]

template<typename T , typename std::enable_if< std::is_integral< T >::value &&!std::is_same< T, uint8_t >::value, std::nullptr_t >::type = nullptr>

uint16_t m5::unit::tcs3472x::calculateSaturation ( const T atime )

inline

Calculate Saturation.

Parameters

atime ATIME raw value (integer types other than uint8_t are treated as raw values too)

Returns: Saturation value

◆ calculateSaturation() [3/3]

uint16_t m5::unit::tcs3472x::calculateSaturation ( const uint8_t atime )

Calculate Saturation.

Parameters

atime ATIME raw value

Returns: Saturation value

Note: Ripple saturation is also considered (in Analog)

◆ make_gamma_table()

template<size_t Size = 256>

M5_UNIT_COLOR_UTILITY_UNIT_COLOR_UTILITY_CONSTEXPR std::array< uint8_t, Size > m5::unit::tcs3472x::make_gamma_table ( const float gamma = 2.2f )

Make gamma table.

Template Parameters

Size	Table size

Parameters

gamma Gamma value. Each entry is (index / 255)^gamma * 255 (rounded)

Returns: std::array<uint8_t, Size> gamma table

Note: Make on compile time if it can; The sensor values are linear in light. Use 1/2.2 to show them on a display (sRGB-like encoding), and 2.2 - 2.8 to drive an LED by PWM so that it looks right to the eye

◆ ms_to_atime()

uint8_t m5::unit::tcs3472x::ms_to_atime ( const float ms )

inline

ms to ATIME

Parameters

ms	Integration time (ms)

Returns: ATIME raw value (clamped)

◆ ms_to_wtime()

std::tuple< uint8_t, bool > m5::unit::tcs3472x::ms_to_wtime ( const float ms )

ms to WTIME and WLONG

Parameters

ms	Wait time (ms), clamped to 2.4 - 7372.8

Returns: Tuple of (WTIME raw value, WLONG)

◆ wtime_to_ms()

float m5::unit::tcs3472x::wtime_to_ms	(	const uint8_t	w,
		const bool	wlong )

inline

WTIME and WLONG to ms.

Parameters

w	WTIME raw value
wlong	True if WLONG is set (x12)

Returns: Wait time (ms)

Classes

Namespaces

Functions

Variables

Detailed Description

Function Documentation

◆ atime_to_ms()

◆ calculateColorTemperature()

◆ calculateCPL()

◆ calculateCRATIO()

◆ calculateLux()

◆ calculateMaxLux()

◆ calculateSaturation() [1/3]

◆ calculateSaturation() [2/3]

◆ calculateSaturation() [3/3]

◆ make_gamma_table()

◆ ms_to_atime()

◆ ms_to_wtime()

◆ wtime_to_ms()