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Please Help Me — Parallax Forums

Please Help Me

raejjraejj Posts: 14
edited 2009-01-30 20:13 in Learn with BlocklyProp
Hi all,

I chose an Interactive Wall Panel for my Assistive Technology Project. It features three sensors that I purchased from parallax: TCS230-DB color sensor, PIR sensor, and the IR transmitter/receiver.

In the first activity, my intention is to have my client drop a ball past the color sensor. Depending on the color of the ball, different musical patterns will be played. The second activity has the client spinning a roller. This motion will be detected by the PIR sensor, which will activate lights and sounds. Lastly, the last activity will feature the IR transmitter/ receiver separated by a divider. When a string is pulled, the connection between transmitter and receiver will be made. This will turn on a fan, which will blow around confetti in an enclosed container.

Does this sound feasible? I was reading about the M&M sorter and it looks like the object needs to be in close proximity in order to be sensed.

Does anyone have any suggestions as to what components I need for this project? I am still working out the full schematic with currents and voltages.

Any help would be greatly appreciated and I thank you all in advance.

Comments

  • Jessica UelmenJessica Uelmen Posts: 490
    edited 2009-01-28 22:01
    Hi raejj,

    From the description of your project, it does seem that the sensors you purchased will allow you to complete your project. I would suggest reading the product documentation and running some of the sample code in order to get better acquainted with how each sensor works. From there you can decide if you will need any additional equipment.

    All product documentation and sample code are available on each sensor's product page under "Downloads and Resources". I've also included the links below:

    TCS230-DB Color Sensor
    PIR Sensor
    Parallax 433 MHz RF Transceiver Package

    One of the first things that you will want to test is the sampling rate of the color sensor. Dropping a ball in front of it may be too fast for the sensor to detect color, which will certainly be something you would want to know.

    I am not sure which BASIC Stamp module you are planning on using, but if you have not programmed with the BASIC Stamp before, I encourage you to read through What's a Microcontroller to learn the basics of programming with the BASIC Stamp 2. If you plan on using any module other than the BASIC Stamp 2, you may have to do some research when programming as the clock speed will be different, which affects most of your PBASIC commands - FREQOUT, PULSOUT, RCTIME, etc.

    Happy Developing!

    Jessica

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jessica Uelmen
    Education Department
    Parallax, Inc.

    Post Edited (Jessica Uelmen (Parallax)) : 1/28/2009 10:41:26 PM GMT
  • Mike GreenMike Green Posts: 23,101
    edited 2009-01-29 00:25
    I suspect you will have problems with the PIR sensor in that it reacts relatively slowly to changes in passively emitted (long wavelength) IR. The roller is likely to be a fairly uniform temperature which won't activate the PIR sensor. You may do better with a magnet inside the roller and a Hall-effect sensor that would produce pulses as the magnet rotates end-over-end near the Hall-effect sensor.

    The color sensor is unlikely to react quickly enough if the colored ball is in free-fall. It may work fine if the ball rolls down a shallow incline which will keep it in range of the sensor for a longer period. Look at the datasheet for the sensor. You'll see that it produces a pulse train whose frequency depends on the color seen by the sensor. You can get the frequency range up fairly high, so it might work quickly enough for your needs, but you'll have to do the calculations.
  • Mike2545Mike2545 Posts: 433
    edited 2009-01-29 01:53
    Just a quick thought on the color sensor. If the ball were dropped in a tube or pipe, you could use a solenoid to catch and hold the ball until the color were determined then actuate the solenoid to release the ball.

    Mike Green has a good point about the PIR sensor. The Hall-effect sensor is a good alternative or use an LED emitter/detector pair to "see" holes in a disk attached to the axle.
  • UghaUgha Posts: 543
    edited 2009-01-30 00:39
    I agree with everyone else's comments as well... but for the last activity, why use an IR pair when you can just tie the string onto a switch?
  • raejjraejj Posts: 14
    edited 2009-01-30 18:32
    Thanks for all the comments. I have another question.

    Does anyone have any opinion on the MoBoStamp-pe BS2pe MotherBoard? It can be used with the color sensor, and since I have other activities, I figure it may come in handy.
  • Mike GreenMike Green Posts: 23,101
    edited 2009-01-30 19:15
    The MoBoStamp-pe is a very nice unit. It has the advantage of having two identical peripheral co-processors that can take some of the I/O burden off of the Stamp. In particular, these can provide analog to digital conversion, pulse width modulated (PWM) outputs, and a frequency counter. They can also be reprogrammed for other purposes.
  • sylvie369sylvie369 Posts: 1,622
    edited 2009-01-30 20:13
    raejj said...
    Thanks for all the comments. I have another question.

    Does anyone have any opinion on the MoBoStamp-pe BS2pe MotherBoard? It can be used with the color sensor, and since I have other activities, I figure it may come in handy.
    I have one, and I really like it. IMHO you should make sure that you order the Power Input + I/O daughterboard with it right away, mainly to get easy access to the I/O pins. It's my board of choice when I want to quickly set up an analog sensor with a Stamp, because it has ADC through the co-processors.
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