Remote Gate Sensor Project
snyderm4n
Posts: 1
My name is Christian Snyder and I am a Mechanical Engineering student at Southern Methodist University.· I am currently in a design team that consists of 7 mechanical engineering students and no electrical or computer science engineers.· The project given to our team is to design and build a remote gate/alarm system for a visually impaired person.· We have decided to use a magnetic sensor that can detect if the gate is open or closed with a RF module to send and receive information to and from a remote.· The complete system will need to be able to receive a signal from the remote to check for the status of the gate, the gate component will need to send back a signal indicating if the gate is open or closed.· The system will also need to send a signal notifying the owner when the gate is opened.· Since the “product” will be designed for the visually impaired we have decided to use varying tones as the indicators on the remote as well as a vibrating motor.· My team is researching RF modules, microprocessors and other required components but this project is outside of our scope as mechanical engineers so we are looking for help or guidance on this project.·
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Thank you,
Christian Snyder
csnyder@smu.edu
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Thank you,
Christian Snyder
csnyder@smu.edu
Comments
Parallax has a variety of resources available to help get you up to speed with the electrical and programming side of this project. It's best to start with What's a Microcontroller. This text is available for free on our website at www.parallax.com -> Downloads -> Stamps in Class Downloads. The entire book will familiarize you with programming in PBASIC, and the following chapters will be of particular interest to you:
Chapter 3: Digital Input - Pushbuttons
Before moving onto a magnetic sensor that detects if the gate is open or closed, a good place to start would be to prototype the design with a pushbutton. This will help you understand the basics of reading digital inputs, and will make programming the magnetic sensor much easier later.
Chapter 4: Controlling Motion
This chapter covers programming the BASIC stamp to control a servo. This will help you when programming your vibrating motor later.
Chapter 8: Frequency and Sound
This chapter covers playing different tones through a piezospeaker. You can also combine concepts from Chapter 3 to read a digital input (pushbutton to start, magnetic sensor later) and play a tone.
A link to the BASIC Stamp Activity kit can be found here. This kit contains everything you need to learn programming in PBASIC as well as building simple circuits.
You may also want to check out the Parallax 433 MHz RF Transceiver Package. This product page contains everything you'll need to get started when working with RF modules, including manuals and sample code.
Since you're going to be working with two boards communicating wirelessly, the best thing is to tackle each part of the solution separately. First, start with one board and test each sensor separately. For example, first add the speaker and make sure it plays a tone when the gate is opened, and another when the gate is closed. Then disconnect the speaker and test the vibrating motor. Then try combining the two. Once you're sure each sensor is operating correctly, move the speaker and vibrating motor to the other board and connect it to the other board with wires. Finally, when you're sure the boards are communicating correctly, move on to RF communication. This way, if you run into problems, you can isolate them to a single source, and save a lot of debugging time.
I hope this helps get you started, and let us know if you need any further assistance!
Happy Developing!
Jessica
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Jessica Uelmen
Education Department
Parallax, Inc.
Post Edited (Jessica Uelmen (Parallax)) : 2/10/2009 8:41:02 PM GMT
You'll need two microcontrollers (one for the gate transmitter and one for the house receiver). If you need a longer range than the modules Parallax has, Sparkfun has a ultra-long range modem (1,500 meters?) that would work. I think they also have a cell phone pager motor that you can use.