| 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061 |
- ==============================
- OPT4060 driver
- ==============================
- 1. Overview
- =============================
- This driver supports the Texas Instrument RGBW high resolution color sensor over
- I2C.
- https://www.ti.com/lit/gpn/opt4060
- The driver supports:
- - Raw values for red, green, blue and clear.
- - Illuminance values.
- - Scaled color values for red, green and blue.
- - IIO events for thresholds.
- - IIO triggered buffer using both its own data ready trigger and triggers from
- other drivers.
- 2. Illuminance calculation
- =============================
- Illuminance is calculated using the wide spectrum green channel.
- lux = GREEN_RAW x 2.15e-3
- The value is accessed from:
- /sys/bus/iio/devices/iio:deviceX/in_illuminance_input
- See section 8.4.5.2 in the data sheet for additional details.
- 3. Color scale values
- =============================
- The sensor has different sensitivity for the different color components and
- compensating factors are exposed from the driver.
- The values are accessed from:
- /sys/bus/iio/devices/iio:deviceX/in_intensity_red_scale
- /sys/bus/iio/devices/iio:deviceX/in_intensity_green_scale
- /sys/bus/iio/devices/iio:deviceX/in_intensity_blue_scale
- A userspace application can multiply the raw values with the scale values so
- that for a particular test light source, typically white, the measurement
- intensity is the same across the different color channels. This is calculated
- in the following way:
- R = RED_RAW x SCALE_RED(2.4)
- G = GREEN_RAW x SCALE_GREEN(1.0)
- B = BLUE_RAW x SCALE_BLUE(1.3)
- The data sheet suggests using the scaled values to normalize the scaled R, G
- and B values. This is useful to get a value for the ratio between colors
- independent of light intensity. A userspace application can do this in the
- following way:
- R_NORMALIZED = R / (R + G + B)
- G_NORMALIZED = G / (R + G + B)
- B_NORMALIZED = B / (R + G + B)
- See section 8.4.5.2 in the data sheet for additional details.
|
