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https://github.com/RobTillaart/Arduino.git
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47 lines
802 B
C++
47 lines
802 B
C++
//
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// FILE: UV_sensor.ino
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// AUTHOR: Rob Tillaart
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// PURPOSE: demo
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// DATE: 2021-09-21
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void setup()
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{
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Serial.begin(115200);
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Serial.println(__FILE__);
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}
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void loop()
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{
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Serial.println(indexUV(A0, 1023, 5.0)); // assume UNO analog port
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delay(1000);
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}
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float indexUV(uint16_t pin, int16_t analog_max, float voltage_max)
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{
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uint16_t raw = analogRead(pin);
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float millivolt = (voltage_max * raw * 1000) / analog_max;
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float uvi = 0.0;
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if (millivolt < 50)
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{
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return uvi;
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}
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if (millivolt < 227)
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{
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// linear interpolation between 0..1
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uvi = (millivolt - 50) / (227 - 50);
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return uvi;
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}
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// linear interpolation between 1..11
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// formula derived with spreadsheet.
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uvi = 0.0104865310 * millivolt - 1.289154988;
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return uvi;
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}
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// -- END OF FILE --
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