Jump to content

12 bit resolution for Temperature?


JavaLaurence
 Share

Recommended Posts

The docs for the bricklet state:

 

* Temperature range from -40°C to 125°C

* Output in 0.1°C steps (12bit resolution)

 

So that's a range of 165 degrees, subdivided in tenths.. that's 1650 possible values. 12 bits give you the integer range 0..4095. The 1650 possible temperature range comfortably fits in 11 bits (0..2047), but not in 10 bits (0..1023). Does that mean we're talking about 1 extra noise bit (the LSB), or do the so-called analog values arrive offset by some base value for -40 degrees?

 

Secondly, if "Output in 0.1°C steps", then why does Brickv show my temperature values toggling noise-like between 12.50 and 12.56 degrees, with never a value in-between, as one would expect?

 

I see the same phenomenon with my Distance IR values.. they toggle between two values that are several units of accuracy apart, not just the single unit.

 

It's as if the claimed accuracy is wrong, but I'm sure that's not the explanation. Just curious.

Screen_Shot_2013-02-22_at_Friday_22_February_2013.png.7d3e8a0d89bd1e1d35e23b9ffb6e4d2d.png

Link to comment
Share on other sites

The claimed resolution is conservatively described as 0.1°C, what you are seeing is a resolution of 0.06°C.

 

Depending on the Brick/Bricklet there is a lot of integrating and averaging going on. So the value jumps you are getting may not always be intuitive.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...