[SOLVED] DHT returns 00 01 93 ff ff ff ff ff ff

Hello,
often my DHT sensor returns 00 01 93 ff ff ff ff ff ff with translates into NaN and NaN.
What is this value?

Hi @LuCavallin,

Just to be really certain, can you show us a list with the values you get?
Say … a screenshot of your terminal.


Coming back to your problem, the DHT sensor is know for having lots of noise on its lines.
When a NaN is read, this means there was noise down the line and the values couldn’t be read from the sensor.


For this issue I have a solution for you that I’ve developed a couple of weeks ago.
Here are 2 topics that have as a subject the noise on the DHT lines:

Nonetheless, you also have access to this solution from within our GrovePi repository.
Here’s a link to the algorithm which helps reduce the noise between the DHT and the GrovePi:

Please try out some of those example programs and tell us how it goes.


If there’s anything else that needs our attention, please inform us.

Thank you!

Hi Robert,
I understood what the problem was - be ready, it’s rather stupid.
I was reading light and temperature concurrently :smiley:

Hi @LuCavallin,

I’m glad everything solved out.

The GrovePi library sometimes has some timing issues and because of this, I’d suggest you use locks when developing multi-threaded applications.

Thank you!

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