Wednesday 6 July 2016

Comparing solar radiation shields

I have three temperature sensors with calibration data that I want to test with different solar radiation shields.


From the left, normal shield made from plastic plates, tube made from twinwall sheet used in advertisement plates, same kind of tube but with fan.

Sensors (DS18B20) are read with OWFS and a small python script that starts the conversion for all sensors, reads them and then sends them to a Google Sheet using gspread. For some reason simultaneous conversion doesn't work for me, I get cached values. So I changed the script to just read sensors one after the other. Reading is done every minute. Also writing to Google Sheets is really slow, especially when done cell by cell. So I moved writing to Sheets to a different script that is run once a day.

Currently data is flowing in nicely, but I forgot to check which sensor is in which shield, so I have to check that the next time I travel to where those sensors are.

Writing to Google sheets is really easy with gspread, I can definitely recommend it if you need to work with Google sheets.

Raw data can be found in this Google sheet.

Python script in https://github.com/mika-koivusaari/read_ds18b20_gspread