UVI-01 Sensor and Arduino Uno

Other Hardware Sensors
1

Hello!

I have started a project to build a weather station with arduino and I have received my Reyax UVI-01 sensor, but I have problems with adding it to the arduino. I don't know which components are needed for connecting to the arduino (e.g. op-amp) and I would need help with the source code for reading the UVI value!

Thank you in advance,

David

2

Please post the link to the datasheet of the sensor.
The more info you give the better help you can expect.

3

Thanks to Google, I found the data sheet in 5-10 seconds :slight_smile:

You need a 1meg resisitor and an opamp. I attached the circuit from the data sheet.
Attach the output of opamp the an analog input on the Arduino. Calibration depends on your application.

Perhaps some one can suggest the best choice of opamp. The 1meg R value concerns me somewhat. Is a higher quality opamp required?

4

See:

http://www.reyax.com/Module/UVI/UVI-01-E.pdf

UV1-circuit.JPG

5

Thank you for your reply! I was on vacation, so I was not able to write back.

I am using this circuit now with a CA3140 opamp to get the UVI level!
This is a part of my arduino configuration, which I have from the AirPi project:

float result = analogRead(UVIPIN); // Input-Pin lesen
Serial.print("Analog Reading = ");
Serial.println(result);

float vout = result/1023.0*5.0;
float sensorVoltage = vout / 471;
float millivolts = sensorVoltage * 1000;
float UVI = millivolts * (5.25/20);
Serial.print("UV-Level: ");
Serial.print(UVI); // Überprüfung des gelesenen Wertes
Serial.println(" UVI");

But I still get wrong results, I am always getting 1.64 UVI during the day and there is a UVI station in my town which shows values from 1.5 to 5.2 today!

Thank you again,
David

6

I am always getting 1.64 UVI

what is the output of these 2 lines:

Serial.print("Analog Reading = ");
Serial.println(result);

7

What is the actual behavior? If you cover the sensor does the value drop towards zero? If you filter the sunlight does the value change?

8

About 5 hours ago it was: Analog Reading = 602 and now it is about 11 and UVI is 0,03

When the sensor is covered, UVI is near 0 (0-0,05) and when its filtered the UVI is lower than uncovered, but generally the UVI should be higher than it displays. I think that the formula is not correct.
I am currently using the attached circuit!

uvi-01.jpg