Problem ploting Data


#1

Hi!

I´m using a Node MCU D1 mini and a ds18b20 temperature sensor. The sensor works fine, I´m able to plot the data in the graphs but every now and then it displays a -127 or a 85 and then returns to show the real data. Can anyone give me a hint of where is the problem?

Best Regards,

Tomás


#2

It seems an issue with the sensor, not an issue with platform.

I suggest to filter the sensor readings in order to discard these values.


#3

Hi Ega!

Thanks for the response. Do you suggest from the code or some kind of electronic filter?

Cheers!

TOmas


#4

From the code, even there is another post that makes reference that when this sensor has an error, send this value (-127), I didn’t knew this, just read 5 minutes ago

Here is what I would try

Hope this helps


#5

And if you share your code (in the right way), I can see what can be done according your particular case.


#6

Thanks ega!

I´ve actually done this but it doesn´t get better. I will try with > < and decrease the range of reading. Will post the result!

Cheers


#7

You can even try to restringe the range of the measurement, I mean only accept values if they are ± 20 (for example, this thereshold should be determinated by the speed of the phenomena changes and the lapse between the measurements) from the last reading, but must be carefull because you can get a missreading as reference (for example the first time when you turn on or reset the device) and loss all the good readings.

I had done something like this, and counted how many consecutive missreadings have, and if the amount of missreadings exceeds a thereshold, I took another reading as reference.

Hope this helps