[werk_ag]

Today I tried to measure the voltage produced by my photodiode with a 235 ohm R in parallel. I recorded a maximum of 330 mV (weather stations near me have recorded about 660 w / m 2). I believe that by calibrating a little the resistance we can get a 1.1 volt (considering that from me 1300 w / m2 have a limit more than ample))

Just be aware of this:

"There is a trade-off between the desire to increase the output voltage (by increasing the resistance) and the need to make sure that the pyranometer output remains linearly proportional to the incident sunlight. "

This is from the link you published. It's valid for my solar sensor and probably for any other that use the same principle.

[loriz71]

Just be aware of this:

"There is a trade-off between the desire to increase the output voltage (by increasing the resistance) and the need to make sure that the pyranometer output remains linearly proportional to the incident sunlight. "

This is from the link you published. It's valid for my solar sensor and probably for any other that use the same principle.

With some calcolation I think 47 ohm is a good solution to use your same amplification solution.
I started to build the X. A couple of questions. The variable resistor is used just 15k? If I do not use the fan can live without it? To test it out I can connect the TX only with usb? Thanks.
Loris

[werk_ag]

... A couple of questions. The variable resistor is used just 15k?

On the TX board, the R8 variable resistor must be adjusted to 10K as close as you can.

If I do not use the fan can live without it?

The fan is not required. You may build your Radition Shield without it.

To test it out I can connect the TX only with usb?

For testing, yes you can!

On the TX software, find this line: //#define Local_TestMode
and uncomment it.

Compile and upload.
Open Arduino IDE serial monitor. Almost every 3 seconds you will see a line of data. This data follow the easyweather.dat format.

There is an easier way to view the data sent by the USB port:
Install the Easyweather_RS232_Logger (freeware)
Download it from here: http://www.meteoestarreja.info/logger.php/

[loriz71]

Hello
I have some doubts.
I have indicated in Annex positions of the cathodes of the LEDs and diode. Are they correct?
I have some difficulty in finding a variable resistance 15 k ohm (I find 10 k). what is the function of R8? I hope that by next week all the components to test the TX arrives
B.R.
loris

[werk_ag]

Hi Loris

The Led's and the diode are correct. At first look they seems reversed but they are not. The MosFET's drives the GND line.
The diode is only a protection just in case someone use the fan as a wind mill.

Any variable resistor greater than 10K will be fine for R8. Even a fixed 10K 1% resistor will do the job, but you loose the possibility to fine adjust your wind vane. Usually this procedure is not necessary, the variable resistor is there, just in case...