Code

Temperature sensors

CAN ports : https://discuss.ardupilot.org/t/how-to-send-data-from-arduino-to-pixhawk-using-i2c/99814

Temp sensor datasheet : https://www.analog.com/en/products/ds18b20.html 

Applets : https://github.com/ArduPilot/ardupilot/tree/master/libraries/AP_Scripting/applets 

Ardupilot forum: https://ardupilot.org/copter/docs/common-optional-hardware.html 

Temp sensor ardupilot: https://ardupilot.org/copter/docs/common-temperature-sensor.html 

Pihawks with Raspberry 

https://ardupilot.org/dev/docs/raspberry-pi-via-mavlink.html