TEROS 12 and SDI-12
How many sensors do you like to connect? As far as I now you can just assign adress "0" to the sensor and it will send data one time over serial (DDI) . After sending data the sensor will go into sdi12 mode. So if you don't need the bus you could do with serial. Also keep in mind that the pycom board are not 5V tolerant. So you need a lever shifter.