Problem with ds18b20 and below -15 celsius

[matha]

Hello,

I have a problem with ds18b20 measuring under -15 celsius temps. I have two ds18b20 connected to PHOTON and i am using onewire and dallas libraries to read temps from sensors. Everyting is working fine but when outside temp drops under -15 celsius the ds18b20 returns -127c (disconnected).
Any ideas?

[Muskie]

Perhaps this post can shed some light for you:

[RESOLVED]Photon stopped reading temps from DS18B20 after months of use

So here’s the deal. I found that the problem lies with the port of the dallas temperature library that I was using (“spark-dallas-temperature”). The issue is with the -2032 value defined for DEVICE_DISCONNECTED_RAW constant in the header file which should read -7040. [image] This was reported by RobTillaart who opened this issue on GitHub. These changes have already been made to the original Miles Burton Arduino library. I’ve tested out the change on my own Photon and everything seems to be w…

[matha]

Hello,

Thanks for the help. Found that also later yesterday. Now I just figure out how to edit that included library in my project.

[matha]

Thank You very much. Now everything is working. Thanks for quick help!
–Matias–