# Written by David Neuy
# Version 0.1.0 @ 03.12.2014
# This script was first published at: http://www.home-automation-community.com/
# You may republish it as is or publish a modified version only when you
# provide a link to 'http://www.home-automation-community.com/'.

# Lightly Modified by Sean Kelley
# To include second sensor for soil temperature
# No need to provide a link to Sean @ http://www.brickstobits.com

#install dependency with 'sudo easy_install apscheduler' NOT with 'sudo pip install apscheduler'
import os, sys, Adafruit_DHT, time
from datetime import datetime, date
from apscheduler.schedulers.background import BackgroundScheduler

#load drivers for soil temp sensor
os.system('modprobe w1-gpio')
os.system('modprobe w1-therm')

# soil sensor output file
soil_temp_sensor = '/sys/bus/w1/devices/28-000006c3a429/w1_slave'

#air temp sensor setup
sensor                       = Adafruit_DHT.AM2302 #DHT11/DHT22/AM2302
pin                          = 4
sensor_name                  = "outside"
hist_temperature_file_path   = "sensor-values/temperature_" + sensor_name + "_log_" + str(date.today().year) + ".csv"
hist_soil_temperature_file_path   = "sensor-values/temperature_" + 'soil' + "_log_" + str(date.today().year) + ".csv"
latest_temperature_file_path = "sensor-values/temperature_" + sensor_name + "_latest_value.csv"
latest_soil_temp_file_path   = "sensor-values/temperature_" + 'soil' + "_latest_value.csv"
hist_humidity_file_path      = "sensor-values/humidity_" + sensor_name + "_log_" + str(date.today().year) + ".csv"
latest_humidity_file_path    = "sensor-values/humidity_" + sensor_name + "_latest_value.csv"
csv_header_temperature       = "timestamp,temperature_in_fahrenheit\n"
csv_header_soil_termperature = "timestamp,temperature_in_fahrenheit\n"
csv_header_humidity          = "timestamp,relative_humidity\n"
csv_entry_format             = "{:%Y-%m-%d %H:%M:%S},{:0.1f}\n"
sec_between_log_entries      = 60
latest_humidity              = 0.0
latest_temperature           = 0.0
latest_soil_temperature           = 0.0
latest_value_datetime        = None

# SOIL TEMP CODE functions

def temp_raw():
    f = open(soil_temp_sensor, 'r')
    lines = f.readlines()
    f.close()
    return lines

def read_soil_temp():

    lines = temp_raw()
    while lines[0].strip()[-3:] != 'YES':
        time.sleep(0.2)
        lines = temp_raw()
    temp_output = lines[1].find('t=')

    if temp_output != -1:
        temp_string = lines[1].strip()[temp_output+2:]
        temp_c = float(temp_string) / 1000.0
        temp_f = temp_c * 9.0 / 5.0 + 32.0
        return temp_f

# AIR TEMP/HUMIDTY functions

def write_header(file_handle, csv_header):
  file_handle.write(csv_header)

def write_value(file_handle, datetime, value):
  line = csv_entry_format.format(datetime, value)
  file_handle.write(line)
  file_handle.flush()

def open_file_ensure_header(file_path, mode, csv_header):
  f = open(file_path, mode, os.O_NONBLOCK)
  if os.path.getsize(file_path) <= 0:
    write_header(f, csv_header)
  return f

def write_hist_value_callback():
  write_value(f_hist_temp, latest_value_datetime, latest_temperature)
  write_value(f_hist_hum, latest_value_datetime, latest_humidity)

  # added for soil temp
  write_value(f_hist_soil_temperature, latest_value_datetime, latest_soil_temperature)

def write_latest_value():
  with open_file_ensure_header(latest_temperature_file_path, 'w', csv_header_temperature) as f_latest_value:  #open and truncate
    write_value(f_latest_value, latest_value_datetime, latest_temperature)
  with open_file_ensure_header(latest_humidity_file_path, 'w', csv_header_humidity) as f_latest_value:  #open and truncate
    write_value(f_latest_value, latest_value_datetime, latest_humidity)
  # added for soil temp
  with open_file_ensure_header(latest_soil_temp_file_path, 'w', csv_header_soil_termperature) as f_latest_value:  #open and truncate
    write_value(f_latest_value, latest_value_datetime, latest_soil_temperature)

# Mix of step one code and new soil code (step 2)

f_hist_temp = open_file_ensure_header(hist_temperature_file_path, 'a', csv_header_temperature)
f_hist_hum  = open_file_ensure_header(hist_humidity_file_path, 'a', csv_header_humidity)

#soil added
f_hist_soil_temperature  = open_file_ensure_header(hist_soil_temperature_file_path, 'a', csv_header_soil_termperature)

print "Ignoring first 2 sensor values to improve quality..."
for x in range(2):
  Adafruit_DHT.read_retry(sensor, pin)

print "Creating interval timer. This step takes almost 2 minutes on the Raspberry Pi..."
#create timer that is called every n seconds, without accumulating delays as when using sleep
scheduler = BackgroundScheduler()
scheduler.add_job(write_hist_value_callback, 'interval', seconds=sec_between_log_entries)
scheduler.start()
print "Started interval timer which will be called the first time in {0} seconds.".format(sec_between_log_entries);

try:
  while True:
    hum, temp = Adafruit_DHT.read_retry(sensor, pin)
    if hum is not None and temp is not None:
      ftemp = (temp *9.0) / 5.0 + 32.0
      latest_humidity, latest_temperature = hum, ftemp
      latest_value_datetime = datetime.today()
      latest_soil_temperature = read_soil_temp()
      write_latest_value()

    time.sleep(1)

except (KeyboardInterrupt, SystemExit):
  scheduler.shutdown()