Difference between revisions of "S14: Android based home monitoring system"

Revision as of 19:17, 22 May 2014

Grading Criteria

Android based home monitoring system

Abstract

The home monitoring system is designed to monitor light and temperature of different rooms. The monitoring system will monitor light and temperature of different rooms and report the status to the user via an android application.

Features

1. Light and temperature monitoring of multiple rooms
2. Android application to view status of sensors

Team Members

1. Om Narasimhan
   • Software design and Android App development
2. Aysha Malik
   • Hardware interface design and integration
3. Sri Latha Ayyannagari
   • FreeRTOS driver design and development

Schedule

Parts List & Cost

Design & Implementation

The project was completed in a number of steps

1. Device driver development

2. Android Application development

Hardware Design

Fig 1. Bluetooth module

Basic Bluetooth module (JY-MCU HC-06) was purchased from ebay for $8 including shipping. This particular series (HC-06) has four pins RX, TX, VCC and GND and can only work in slave mode. The module specification mentions that the module can be reprogrammed, but the KEY and STATE pins are not available in this series (HC-06).

Note: Although VCC pin indicates that the module works with 3.6-6V, connecting it to the LPC1758 3.3V output worked fine.

Hardware Interface

This project uses UART2 for communication.The default setting for UART is: Baud Rate - 9600, no parity, one start bit and one stop bit.

Software Design

Fig 3. Android application flowchart

Fig 4. Device driver flowchart

Parameters are monitored by devices placed in each room. The monitoring device communicates to android application using Bluetooth. The application records incoming data from different devices and continuously analyses it. Interpretation of the data can either be done in real time or at fixed intervals and logical decisions are taken (e.g, no motion sensor update for X minutes, so switch off lights, or based on the historical data, switch on lights at a particular time ..etc)

In this project software design has two components: device driver and android application.

Following figures (Fig 3 and Fig 4 )give an overview of the individual components.

• Android application is implemented in three parts:

1.Start Screen

• Enable Bluetooth
• Upon selection of Room connect to the corresponding device

2.Communication Screen

• Once connection is established, status is shown as connected or a message “connection failed”
• Send characters for information request and display incoming data

Current Temperature

Temperature History

Current Lumosity

Lumosity History

3.Graphing Screen

• Plot the requested weather data.

• Free RTOS application is implemented in two parts

1. Data Structure

• Every board gathers temperature and Luminosity samples at fixed intervals. The interval is configurable and was set at 5sec

2.Data gathering and transfer Protocol

• Application GUI

We implemented the Application GUI in three parts

● The first screen for application is for home station selection

○ <insert screenshot here>

● As you can see in the screen shot, there are three buttons to select among three home stations. Upon selecting a weather station (denoted by “roomX”, X => 1, 2, and 3), the application establishes a connection to the Bluetooth agent in the weather station. ● Once connection is established, the status is shown to the user as “connection established” or “connection failed”

● There are 4 different buttons viz,

    Current temperature 		Read the current temperature
    Current luminosity		        Read the current luminosity
    Historical temperature		Historical temperature data and graphs
    Historical luminosity 		Historical luminosity data and graphs

○ <Insert screen shots for all these four here>

● Graphing method

○ Our graphics are primarily based on the library “androidplot” downloadable from (www.androidplot.com)

○ AndroidPlot is a very powerful package to plot graphs. The input for graphing method are two arrays of type Number. To plot an XY graph, these numbers are converted to XY-Series data type and use a LineandPointFormatter class. Once X-axis plane is fully plotted, another series will be used to plot Y- axis plane.

• Application configuration

<TODO>

• Data Analysis

<TODO>

• Data structures

Every board gathers temperature and Luminosity samples at fixed intervals. The interval is configurable and default is set at 5sec. Initially, our first choice was to use a FIFO for storing these readings. But then, it became very difficult to discard older entries. Although we planned to have a timeout mechanism associated with every entry, later we figured out that a FIFO implementation based on a circular buffer would be easier to implement and maintain.

Here is a graphical representation of our FIFO based on a circular buffer.

• Communication protocol

<TODO>

Implementation

This section includes implementation, but again, not the details, just the high level. For example, you can list the steps it takes to communicate over a sensor, or the steps needed to write a page of memory onto SPI Flash. You can include sub-sections for each of your component implementation.

Testing & Technical Challenges

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My Issue #1

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Conclusion

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Project Video

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Project Source Code

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References

Acknowledgement

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References Used

Appendix

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