Raspberry Pi Environmental Monitoring - Revision history

Michael.mast: /* Using Node-Red to pull from Sensor */

2020-05-19T14:36:32Z

Using Node-Red to pull from Sensor

2020-04-19T15:44:56Z

Send values to MQTT

2020-04-19T15:08:34Z

Configure for writing to database (LEGACY)

2020-04-19T15:05:34Z

Base Script

2020-04-19T15:04:14Z

Configure for writing to database (LEGACY)

2020-04-19T15:01:03Z

Send values to MQTT

2020-04-19T14:55:08Z

Base Script

2020-04-19T14:54:53Z

Send values to MQTT

2020-04-19T14:54:10Z

Send values to MQTT

2020-04-19T14:18:51Z

Send values to MQTT

@@ Line 267: / Line 267: @@
 sudo apt install wiringpi
 </pre>
-*After adding the rpi-dht11 node to the flow, I gave it the following values
+*Add inject module with as timestamp. I chose to inject every 5 seconds.
 **Sensor : DHT11
 **Pin numbering : WiringPi (rev.1)
 **Pin number : 7
 *This breaks out to a function node that changes C to F <ref>https://groups.google.com/forum/#!topic/node-red/bkmv6kMAFlM</ref>
 <pre>
@@ Line 279: / Line 281: @@
 return msg;
 </pre>
-*We also send the output of the rpi-dht11 to a set node to change the payload to msg.humidity.
+*Now use a change module to change msg.payload to msg.humidity.
-*Then add two gauges to represent temperature and humidity.
+*Both the function and change modules connect to MQTT out modules that connect to my MQTT server.
 ==Graph Display==

@@ Line 50: / Line 50: @@
 import paho.mqtt.client as mqtt
-broker_address="xxx.xxx.xxx.xxx"
+def mqttpub(pm1,pm2):
-username="<username set on broker>"
+    broker_address="xxx.xxx.xxx.xxx"
-password="<password set on broker>"
+    username="<username on broker>"
-mqttc=mqtt.Client()
+    password="<password on broker>"
-mqttc.username_pw_set(username, password)
+    mqttc=mqtt.Client()
-mqttc.connect(broker_address)
+    mqttc.username_pw_set(username, password)
 ...
-mqttc.publish("air/livingroom/pm25",pm25)
+              mqttpub(pm25,pm10)
 </pre>

@@ Line 96: / Line 96: @@
+)
 ...
-mycursor.execute('INSERT INTO aqi (pm25, pm10, date) VALUES (%s, %s, %s)' % (pm25,pm10,'now()'))
+              mycursor.execute('INSERT INTO aqi (pm25, pm10, date) VALUES (%s, %s, %s)' % (pm25,pm10,'now()'))
+              mydb.commit()
 ===Full Modified Script===
 <pre>

@@ Line 30: / Line 30: @@
 PM2.5:  0.6 , PM10:  0.6
 PM2.5:  0.7 , PM10:  0.7
 </pre>

@@ Line 80: / Line 80: @@
 Now we edit the script to work with mysql<ref>https://www.w3schools.com/python/python_mysql_insert.asp</ref><br>
 Please note that of this writing I the script searches the entire database for 0 values and deletes them. I need to go back and update to simply not write 0 values in the first place.
 ===Full Modified Script===

@@ Line 35: / Line 35: @@
 *Work in progress.
 <ref>https://pypi.org/project/paho-mqtt/#constructor-reinitialise</ref><ref>http://www.steves-internet-guide.com/into-mqtt-python-client/</ref>
 <pre>
 pip install paho-mqtt
 </pre>

@@ Line 15: / Line 15: @@
 *<b>NOTE</b> : This appears to run in python2. When attempting to run with python3 I received indentation errors. Should be easy to fix, but I am lazy and this is not a critical system.
 <pre>
 mkdir -p /home/pi/build/air && cd /home/pi/build/air
 sudo apt install git-core python-serial python-enum mariadb-server python-mysql.connector