We have connected a Celsius sensor to Pixhawk PX4fmu 2.4.8 and trying to fetch the value of temperature of the water. We tested the sensor with an arduino UNO board and it is giving perfect readings, but we are not able to fetch the water temperature with the help of pixhawk connected to Raspberry Pi 3 B running the latest Ardusub-Raspbian image. We are running ArduSub V3.5.3 on Qgrouncontrol V3.2.4 and we have enabled the High-res water temperature but it is not showing any value there. We saw one similar forum discussion related to this and followed all the steps asked by you but nothing changed. We would also like to know how to get values for the same sensor using a python script. The tutorials provided on the Ardusub documentation have not been enough for us to completely understand how to run this correctly and it would be really helpful if you provide us details on QgroundControl, Pymavlink and ArduSub.
You can check celsius temperature in QGroundControl in mavlink inspector with SCALED_PRESSURE3 message:
You can read more about mavlink and this message here.
Take a look in “Receive data and filter by message type” if you want to get data with python.
If the documentation was not helpful to provide the necessary information, can you be more explicit about what should be improved or what was not clear ? With this feedback, we can improve the documentation and make it more helpful for you and everybody