You'll need software running on your microcontroller to read data from the connected sapflow gauge. See here for the Arduino code we used for the D32 Pro.
Edge Compute Node
If you're using microcontrollers with WiFi connectivity, it's very convenient to have all of the data streaming into a single place. We like using a Raspberry Pi as an MQTT broker, collecting data points from all of the networked sensor devices. See here for more info.