Practical exercise #01 – Calculating realtime gas flow using a Raspberry Pi, Arduino, & 4-20mA DP Sensor. Using open-source electronics prototyping platforms based on flexible, easy-to-use hardware and software to read a Differential Pressure from a 4-20mA sensor in a classroom environment.

1. Coal Mine Methane Gas Flow
Measurement
Practical exercise #01 – Calculating
realtime gas flow using a Raspberry Pi,
Arduino, & 4-20mA DP Sensor

2. Session Outcome
By the end of the session participants should be
able to:
“Use open-source electronics prototyping
platforms based on flexible, easy-to-use
hardware and software to read a Differential
Pressure from a 4-20mA sensor in a classroom
environment.”

3. Class Equipment Required
• Raspberry Pi
• Powered USB Hub
• USB WiFi dongle
• Arduino
• Breadboard
• Zener diode, resistors and jumper wires
• Power Adapter 24V DC output
• 24v DC/DC Converter
• 4-20mA DP Sensor

4. Raspberry Pi with Powered USB Hub
and Wifi dongle

5. Arduino and 4-20mA DP Sensor

6. Power Adapter 24V DC output with
24v DC/DC Converter

7. How to get started with the
Raspberry Pi
• Selecting the Distribution
• Imaging the SD Card
• Configuring Raspbian
• Configure Raspberry Pi for
Remote Shell, VNC, and FTP
• Renaming the Raspberry Pi
computer
• Setup a Raspberry Pi with a
hidden WiFi network
• Working with DHCP
• Simplified Setup for Arduino
on Raspberry Pi

8. 4-20ma and loop powered
• 24v DC Power source
• 4-20mA Signal
• Voltage dropped across
the 250 ohm resistor

9. Arduino I/O Protection
• Every I/O pin is to be
protected by a 5.1V
zener diode and 220
ohm 30mA PTC
(resettable fuse).
• The equivalent circuit

10. Arduino IDE
• Initial test sketch
• Uploading
• Serial Monitor
• Testing

11. Arduino simple ModBus slave
• Programming the
Arduino as a simple
ModBus slave
• Serial communications
9600 8N1

12. Symbolic Linking COM Ports
• sudo ln -sf /dev/ttyACM0 /dev/ttyS3

13. Qt
• sudo apt-get install
qtcreator

14. ModBus Master
• Compiling code in Qt
Creator
• Testing with ModBus
slave devices

15. QModBus
• Modifying make files
• Compiling code in Qt
Creator
• Testing with ModBus
slave devices

16. DP Sensor
• 4-20mA signal
• 220 ohm resister
• ADC (0 – 1023)
equivalent to 0 to 5 V
DC

17. Apache Tomcat & Java Development
Kit (JDK)
• Installation of JDK
• Installation of Apache
Tomcat
• Apache Tomcat Web
Application Manager

18. ScadaBR
• Installing WAR file in
Apache Tomcat
• Configuring ScadaBR
• Creating Data Sources
• Using Watch Lists
• Creating a simple
Graphic view

19. Xively
• Creating a Development
Device
• Adding Channels
• API Key, Feed ID, and
Device ID (aka Channel)
• Configuring Publishers
in ScadaBR

20. Raspberry Pi Online Resources
http://www.raspberrypi.org/
http://www.howtogeek.com/138281/the-htg-guide-to-getting-started-
with-raspberry-pi/
http://www.howtogeek.com/141157/how-to-configure-your-
raspberry-pi-for-remote-shell-desktop-and-file-transfer/
http://simonthepiman.com/how_to_rename_my_raspberry_pi.php
http://www.dafinga.net/2013/01/how-to-setup-raspberry-pi-with-
hidden.html
http://baldwisdom.com/simplified-setup-for-arduino-on-raspberry-pi/
http://forums.debian.net/viewtopic.php?f=16&t=61943

21. Arduino Online Resources
http://www.arduino.cc/
http://ruggedcircuits.com/html/ancp01.html
http://erdosmiller.com/products/arduino-4-20ma-shield
http://arduino.cc/en/Tutorial/ReadAnalogVoltage
https://code.google.com/p/simple-modbus/

22. M2M Mango
• http://mango.serotoninsoftware.com/downlo
ad.jsp
• http://tomcat.apache.org/index.html
• http://macgyverdev.blogspot.com.au/2012/08
/raspberry-pi-how-to-get-ssh-and-tomcat.html

23. • http://qmodbus.sourceforge.net/

24. Hartowijaya® is a provider of technical, project, drilling services and operational support for coal
seam gas development projects in Australia and Indonesia.
PO Box 11763, Mackay Caneland, Queensland 4740, Australia
www.hartowijaya.com