moisture_logger.py

from phant import Phant

from serial import Serial

import time

p = Phant('XGXqQ3maWluV1vn9xLgQ', 'moisture', private_key='REPLACEMEWITHPRIVATEKEY')

s = Serial('COM3')

last = None
while True:
    line = s.readline()
    last = last or time.time()
    if time.time() - last > 15:
        last = time.time()
        print(line)
        m = int(line.decode().split('=')[1].strip())
        print(m)
        p.log(m)
        print(p.remaining_bytes, p.cap)

read_moisture.ino

const int analogInPin = A0;  // Analog input pin that the moisture sensor is attached to

int sensorValue = 0;        // value read from the moisture sensor

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  // read the analog in value:
  sensorValue = analogRead(analogInPin);

  // print the results to the serial monitor:
  Serial.print("sensor = ");
  Serial.println(sensorValue);

  delay(2);
}