[werk_ag]

My best suggestion is that you try to make that the sensor in a way that it could be read as it as a Temperature / Humidity sensor. This way the changes on the TX code will be only the needed to read a value from the sensor. Don't forget, that the reading whatever it will be, must further be mapped to an Davis extra sensor, which only accepts data with the lenght of one byte for temperature and one byte for humidity, with some limitation. Please refer to Davis Vantage Serial protocol for more info.

Humidity field: integer from 0 to 100
Temperature field: integer from 0 to 255 with a offset of 90 (positive values only from o to 255-90)

So, think wisely about the output scale of the snow sensor. Belive me, I have really good reasons to be very reluctant to add any kind of sensor that isn't supported by a Davis weather station.