DS18B20 no Value in HomeKit by negativ Temperatur

[gregor-git]

I installed the File like in your YouTube Video and it works perfect, but when I try to measure the temp outside the room with the sensor it shows in the HomeKit app >>no answer<<. So I checked the w1_slave and got - 1520 ( >>pi@raspberrypi:/sys/bus/w1/devices $ cat 28-01344f000003/w1_slave
79 00 17 0f 7f ff 07 10 7e : crc=7e YES
79 00 17 0f 7f ff 07 10 7e t=-1520<<)
Anny idea why it only displays positive Values like inside the room?