Tuesday, April 19, 2011

Arduino Gas Sensor Module

Well I've begun work on the gas and smoke detection module for the Home Manegement system. This involves the use of the two sensors I briefly dicussed in my very first post. The first sensor is the MQ-7 which is a Carbon Monoxide gas sensor which detects CO as well as other combustible gasses, such as Hydrogen or Natural gas. While the second sensor, the MQ-6, which is a Liquified Petroleum Gas sensor, which detects combustible gasses such as LPG, isobutane, and propane in the air and ouputs its reading as an analog voltage. The MQ-7 sensor can measure concentrations of 10 to 10,000 ppm, while the MQ-6 sensor can measure concentrations of 300 to 10,000 ppm.

Basically the code will setup the sensors to measure data from both sensors every 1 second for 10 seconds, then average those values and transmit that average particulate count to the server for further calculations.

For the second phase of the project, I've begun planning for getting a Genesi cloud computer to serve as my Command & Control Server for the system. The Efika MX Smarttop has the following specifications:
  • Freescale i.MX515 (ARM Cortex-A8 800MHz)
  • 3D Graphics Processing Unit
  • WXGA display support (HDMI)
  •  10/100Mbit/s Ethernet
  •  512MB RAM
  •  8GB Internal SSD
  •  802.11 b/g/n WiFi
  •  SDHC card reader
  •  2x USB 2.0 ports
  •  Built-in speaker
  •  Audio jacks for headset 

This computer will host a web server, as well as a database for data logging, and the coding for a visual interface so that a user can easily access sensor zones in the system, and be able to configure various systems to their liking. I plan to use the included Ubuntu Maverick edition that comes with the Genesi computer to further allow the system to be open source and easily reproduceable.

In conclusion from the previous post, I've thrown out the idea of using the SD card for CSS and image hosting for the arduino, because I've decided there will be no web hosting/web server on the arduino other than to transmit/recieve data over the ethernet protocol. So there isnt a need to move forward with that line of thought. I'm trying to following the concept of KISS: Keep It Simple Stupid. I found that coding would not only be complicated to implement a webserver on each arduino sensor module, but it would increase the cost of each module in terms of setup and maintence. (I believe the web hosting was making the Ethernet module consume a lot of power, which in turn heated up the board; I'll test to see if this theory holds.)

The good news is that the Efika has a built in SDHC reader, so I can expand up to 32Gb solid state storage in the future if need be. So only 8Gb of SSD is not so bad; I'm really enjoying the fact that its an Arm-8 processor, this should be interesting.

Stay tuned for updates.

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