Committing source

lab_app/env_log.py

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+#!/usr/bin/env python
+
+'''
+FILE NAME
+env_log.py
+1. WHAT IT DOES
+Takes a reading from a DHT sensor and records the values in an SQLite3 database using a Raspberry Pi.
+ 
+2. REQUIRES
+* Any Raspberry Pi
+* A DHT sensor
+* A 10kOhm resistor
+* Jumper wires
+3. ORIGINAL WORK
+Raspberry Full stack 2015, Peter Dalmaris
+4. HARDWARE
+D17: Data pin for sensor
+5. SOFTWARE
+Command line terminal
+Simple text editor
+Libraries:
+import sqlite3
+import sys
+import Adafruit_DHT
+6. WARNING!
+None
+7. CREATED 
+8. TYPICAL OUTPUT
+No text output. Two new records are inserted in the database when the script is executed
+ // 9. COMMENTS
+--
+ // 10. END
+'''
+
+
+
+import sqlite3
+import sys
+import Adafruit_DHT
+
+def log_values(sensor_id, temp, hum):
+	conn=sqlite3.connect('/var/www/lab_app/lab_app.db')  #It is important to provide an
+							     #absolute path to the database
+							     #file, otherwise Cron won't be
+							     #able to find it!
+	curs=conn.cursor()
+	curs.execute("""INSERT INTO temperatures values(datetime(CURRENT_TIMESTAMP, 'localtime'),
+         (?), (?))""", (sensor_id,temp))
+	curs.execute("""INSERT INTO humidities values(datetime(CURRENT_TIMESTAMP, 'localtime'),
+         (?), (?))""", (sensor_id,hum))
+	conn.commit()
+	conn.close()
+
+humidity, temperature = Adafruit_DHT.read_retry(Adafruit_DHT.AM2302, 17)
+temperature = temperature * 9/5.0 + 32
+# If you don't have a sensor but still wish to run this program, comment out all the 
+# sensor related lines, and uncomment the following lines (these will produce random
+# numbers for the temperature and humidity variables):
+# import random
+# humidity = random.randint(1,100)
+# temperature = random.randint(10,30)
+if humidity is not None and temperature is not None:
+	log_values("1", temperature, humidity)	
+else:
+	log_values("1", -999, -999)