@jvdk I agree with the point made by @evb , why would you want to wire connect the ultrasonic node rather than the usual radio connection ? You are adding levels of complexity and power demands for what reason ? My ultrasonic water tank node (pro-mini+rfm69) is now 2 years on the same 2xAA batteries sending in levels every hour (RTC), the only problem encountered - condensation forming a drip on the face of the ultrasonic head during very low temperatures.