Project: SRTM

What is it? Server Room Temperature Monitor

The project goal is monitor the temperature in a IT Room where the Server machines are running. Provide email alerts if the temperature is greater than a certain setpoint. Furthermore, it is desired to send on regular scheduled "info" emails with the current temperature based on intervals (hours).

Time required: 2hs. Level: beginners

Hardware

• Onion Omega2: OM-O2
• Arduino Dock 2
• Temperature Sensor: DS1820

Firmware

Ω-ware: 0.1.10 b160

Libs/versions

• BusyBox v1.26.2 () built-in shell (ash)
• Python Light
• Python pip

Connecting the temperature sensor

Detail of the PINS involved: GPIO 11, 3V3 and GND.

Pull-up resistor detail on the bottom side:

Configuring the Program

The settings are inside tempMonitor.py :

# setup onewire and polling interval
oneWireGpio = 11 # set the sensor GPIO
pollingInterval = 60 # seconds
infoInterval = 8  # hours

• pollingInterval: sensor update, each 60 seconds the temperature will be compared with the setpoint.
• infoInterval: number of hours between INFO emails.

# setup Temp
setPoint = 22  # Celsius

• setPoint: if the temperature rises above this value an ALERT email will be triggered.

# e-mail settings - change these values with your provider 
sender = 'sender@email'
toaddrs = 'recpient@email'
# Credentials
password = 'xxxxxxxx'

• sender: sender email address
• toaddrs: recipient email address
• password: sender account password

Change your email smtp server based on your service:

server = smtplib.SMTP_SSL('smtp.gmail.com:465') # smtp server

Deployment

Install python

opkg update

Now you can install python-light:

opkg install python-light

Using pip to Install Python Modules

The official Python package manager, pip, is the standard way of installing Python modules on a system. You will get a large selection of available packages from which to choose.

Installing pip

We'll need to first install pip on the Omega:

opkg update
opkg install python-pip

Copy the project files inside a folder

root@Omega-xxxx:~# ls
oneWire.py            tempMonitor.py        temperatureSensor.py
root@Omega-xxxx:~#

Editing the /etc/rc.local File

The /etc/rc.local file is a script that will be executed automatically by the system once the boot sequence is complete.

When your Omega boots, it will read commands from the /etc/rc.local file, and execute them.

# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.
python  /root/tempMonitor.py &  
exit 0

Note: If your command runs continuously and never reaches the exit 0 line in the /etc/rc.local file, then your Omega will not successfully finish it’s boot sequence. To avoid this scenario, make sure you fork the process by adding an ampersand to the end of the command.

Sample Alert Email from the SRTM

Date: Sat, 13 Jan 2018 23:24:41 -0800 (PST)
From: sender@email.com
To: recipient@email.com
Subject: Server Room Temp [ALERT]

2018-01-13 23:24:40 T = 22.125[C] 71.825[F]

References:

Reading a 1-Wire Temperature Sensor

• https://docs.onion.io/omega2-starter-kit/starter-kit-temp-sensor.html

Reading 1-Wire Sensor Data with the Omega

• https://wiki.onion.io/Tutorials/Reading-1Wire-Sensor-Data

Arduino Dock 2

• https://docs.onion.io/omega2-docs/arduino-dock-2.html

Sending Emails With the Omega using Python

• https://wiki.onion.io/Tutorials/Sending-Emails-With-Python

Installing and Using Python

• https://github.com/OnionIoT/Onion-Docs/blob/master/Omega2/Documentation/Doing-Stuff/Installing-Software/Installing-and-Using-Python.md

Running a Command on Boot

• https://docs.onion.io/omega2-docs/running-a-command-on-boot.html

(C) 2018, Hernan Monserrat, License GNU GPL 3
Onion, onion.io, Omega 2 are (C) Onion Corporation, more details: http://onion.io