Hi,
I’m having my dust sensor reading very much zero results…
I have added an SD-card shield to the product to log the values. I don’t think this is relevant, but want to mention it nevertheless.
My concentration seems to hop very fast, one reading I have a concentration of 840, the next one I have 0, then I have 150, then I have 0 twice, etc…
Should I average out the readings, or is something wrong?
PS. The device is standing flat for over 48 hours now, and has been running for more than 14 hours now.
I guess what you see is “background noise”. Probably polluted air gives values well above 1000. Even if you look at the example output on
seeedstudio.com/wiki/Grove_- … nsor#Usage
you will see the fluctuating values.
You could also use some kind of “levelling” or calculate an average like Darell Tan did here:
irq5.io/2013/07/24/testing-the-shinyei-ppd42ns/
Best regards,
Mike
Just a short update: I get very different values depending on the orientation of the sensor.
As mentioned in the last link I posted the sensor should be placed in a vertical orientation.
I didn’t consider this in my measurements first since some pictures (like the air quality box) show the sensor in horizontal placement. According the Darells recommendation I now put it in my box in the upright position.
Regards,
Mike
