Stalker V2.0 - TMP102 negative temps

Products & Technology Arduino & Seeeduino
#1

Hi, The TMP102 library doesn’t produce output correctly for negative temperatures… instead it starts from 0=265 and works backwards… so -1 is reported as 255, -3.25 as 252.25 etc

Any clues how to fix the library so as to report the values correctly? Thanks.

#2

Dear customer,

I’m not sure what is TMP102 you used with.
So better could you give a name?
If you show me a photo it could be more helpful.

Best regards,

Yuri

#3

Hi Yuri,

The Stalker V2.0 has an onboard temperature sensor - the TMP102 - the code for the Stalker V2.0 is on the SeeedStudio Wiki and contains a Library for the TMP102 which is where I believe the problem lies. I am hoping you may be able to advise some changes to the TMP102 library code to solve this issue?

Thanks.

#4

Hi customer,

This code is not compatible with Arduino 1.0 IDE please use Arduino 0023 IDE.
The following code had to be added for negative temperatures to work properly.

temperature = (MSB << 8 ) | LSB;
temperature >>= 4 ; // Value is left shifted in above table. Hence Right shift.
temperature = temperature & 0xFFF;

Also, a new library is uploaded to seeedstudio.com/wiki/Seeeduino_S … #Resources. Please test this.

Best regards,

Yuri

#5

Hi Yuriq,

That works great - thank you.