Hi,
i'm trying to connect the solar radiation sensor with Waspmote's analog pins, so that I don't need to use the sensor board.
I only connected the red (+) wire and the GND one.
The acquisition works fine, and I obtain the following values:

SQ-110 Radiation values:
173
177
200
243
...

I don't know what these numbers correspond to.
Do i need to use some conversion's factors?
What is the measure unit of these values (W/m^2 or different)?
I'm looking forward to solve this problem.

Hi Atomos9317,

reading this sensor directly from Waspmote is not a good option, since it outputs a differential signal that cannot be acquired with the analog-to-digital converter of the microcontroller. You may try to connect the gray shielding wire to GND and the red and black pins to two analog inputs and subtract the values you get in consecutive readings, but I'm not sure if you'll be able to have an accurate measurement.

Regarding the data processing, you may find how to perform this conversion in the sensor's section of the agriculture board technical guide.

Regards.

I tried to connect the black and red pins to two analog inputs as advised, but i have some questions:

for example I obtain the values
220 220
223 223
225 226
232 232
...

What values are? They are mV?
How can i convert these values to determine the solar radiation in W/m^2?
I applied the conversion in your readRadiation library:

val = long(data_apogee[1]) + long(data_apogee[0])*256;
val_def = (val - 32769)*9;
return val_def = val_def/65535;

where data_apogee[1] is the first analog input, and data_apogee[0] is the second one.
Is this procedure correct or I need to apply different conversions?
Please let me know how I can solve the problem.

Hi Atomos9317,

could you please post the complete code you are using and indicate the pins upon which you connected the sensor?

Regards.

Sorry I saw only now the reply, here's the code:

void setup()
{
Serial.begin(9600);
}

void loop()
{
Serial.print("Value read from Analog 3: ");
Serial.println(analogRead(ANALOG3),DEC);
Serial.print("Value read from Analog 4: ");
Serial.println(analogRead(ANALOG4),DEC);
}

This is the base code, where I connect the red and the black wires to ANALOG3 and ANALOG4.

I obtain the values that I posted before.
I tried to do the same thing with Arduino board and I have the same results.

So, when i do the difference between the 2 analog values, what conversion do I have to make in order to obtain the solar radiation?

Hi Atomos9317,

that value you got is expressed in LSBs of the analog to digital converter, you need to convert them into volts multiplying by the voltage reference (3.3V) and dividing by 1023 (10bits, 2¹⁰).

Once you have both values in volts you have to subtract the lower to the higher and apply the conversion given in the technical guide.

Regards.