1==============================
2OPT4060 driver
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4
51. Overview
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7
8This driver supports the Texas Instrument RGBW high resolution color sensor over
9I2C.
10https://www.ti.com/lit/gpn/opt4060
11
12The driver supports:
13- Raw values for red, green, blue and clear.
14- Illuminance values.
15- Scaled color values for red, green and blue.
16- IIO events for thresholds.
17- IIO triggered buffer using both its own data ready trigger and triggers from
18other drivers.
19
202. Illuminance calculation
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22
23Illuminance is calculated using the wide spectrum green channel.
24
25lux = GREEN_RAW x 2.15e-3
26
27The value is accessed from:
28/sys/bus/iio/devices/iio:deviceX/in_illuminance_input
29
30See section 8.4.5.2 in the data sheet for additional details.
31
323. Color scale values
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34
35The sensor has different sensitivity for the different color components and
36compensating factors are exposed from the driver.
37
38The values are accessed from:
39/sys/bus/iio/devices/iio:deviceX/in_intensity_red_scale
40/sys/bus/iio/devices/iio:deviceX/in_intensity_green_scale
41/sys/bus/iio/devices/iio:deviceX/in_intensity_blue_scale
42
43A userspace application can multiply the raw values with the scale values so
44that for a particular test light source, typically white, the measurement
45intensity is the same across the different color channels. This is calculated
46in the following way:
47
48R = RED_RAW x SCALE_RED(2.4)
49G = GREEN_RAW x SCALE_GREEN(1.0)
50B = BLUE_RAW x SCALE_BLUE(1.3)
51
52The data sheet suggests using the scaled values to normalize the scaled R, G
53and B values. This is useful to get a value for the ratio between colors
54independent of light intensity. A userspace application can do this in the
55following way:
56
57R_NORMALIZED = R / (R + G + B)
58G_NORMALIZED = G / (R + G + B)
59B_NORMALIZED = B / (R + G + B)
60
61See section 8.4.5.2 in the data sheet for additional details.
62