ponnus
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Hai,
I am using APDS 9300 light sensor for lux calculation. This sensor have an I2C interface which gives the ADC readings of the sensor. I am reading these values using a microcontroller. It has two channels: CH1 reads only IR, while CH0 reads IR and Visible light. When I used it inside the room, I found that CH1 reading(IR only) is less than CH0 reading, and when i used it in bright sunlight, I got greater IR reading.
But, when I calculated the sensor lux, using the formula provided in the datasheet, I am getting smaller lux, ie, below 15.
The formula for lux calculation is:
These are some readings I got in sunlight:
I am reading the correct channels. Sometimes, I am getting zero lux. When I googled about the lux, it says the lux in sunlight is in 1000s.
Does anyone know about this? Please help me...
I am using APDS 9300 light sensor for lux calculation. This sensor have an I2C interface which gives the ADC readings of the sensor. I am reading these values using a microcontroller. It has two channels: CH1 reads only IR, while CH0 reads IR and Visible light. When I used it inside the room, I found that CH1 reading(IR only) is less than CH0 reading, and when i used it in bright sunlight, I got greater IR reading.
But, when I calculated the sensor lux, using the formula provided in the datasheet, I am getting smaller lux, ie, below 15.
The formula for lux calculation is:
Code:
For 0 ≤ CH1/CH0 ≤ 0.52, Sensor Lux = (0.0315 x CH0) – (0.0593 x CH0 x ((CH1/CH0)1.4))
For 0.52 ≤ CH1/CH0 ≤ 0.65, Sensor Lux = (0.0229 x CH0) – (0.0291 x CH1)
For 0.65 ≤ CH1/CH0 ≤ 0.80, Sensor Lux = (0.0157 x CH0) – (0.0180 x CH1)
For 0.80 ≤ CH1/CH0 ≤ 1.30, Sensor Lux = (0.00338 x CH0) – (0.00260 x CH1)
For CH1/CH0 ≥ 1.30, Sensor Lux = 0
These are some readings I got in sunlight:
Code:
[B]CH0(IR) CH1 CH1/CH0 Lux[/B]
5047 4881 0.967109174 4.36826
5047 4700 0.931246285 4.83886
5047 4697 0.930651872 4.84666
5047 4623 0.915989697 5.03906
5047 4596 0.910639984 5.10926
5047 4588 0.909054884 5.13006
I am reading the correct channels. Sometimes, I am getting zero lux. When I googled about the lux, it says the lux in sunlight is in 1000s.
Does anyone know about this? Please help me...