Discussion in 'The Projects Forum' started by DanW8KMX, Dec 17, 2015.

  1. DanW8KMX

    Thread Starter Member

    Oct 21, 2009
    I hope I am not off topic but I need some help in determining what to do to fulfill a need.
    I need to place a push button (or other signaling initiating device) at one to three doors and have it communicate with a portable receiver giving silent, visual, vibration, and possible audio indication. If audio is included I need to be able to turn that signaling on and off. The receiver has to be somewhat "foolproof" requiring no adjustments. This will be an "RF" system of some sort with a required range of about 200 feet max. The receiver will be small enough so it can be placed in a pant pocket. Only one receiver is required however a backup would be wise.

    The "push button" can be wired but it would simplify installation if it were battery powered. But, battery power has its' own drawbacks, i.e. nobody ever checks the batteries and it will be out of power but everybody will think it is working etc.

    What comes to mind is a system similar to what is used in restaurants where they give the customer a disk about 4 inches in diameter and you place it in your pocket and roam around the property. When you can be seated, the disk vibrates as well as lights up etc. The disk can then be placed on a charging station and is always ready for the next usage. Maybe a system like this can be adapted.
    Any suggestions????

  2. AnalogKid

    Distinguished Member

    Aug 1, 2013
    Here is what I understand you to be describing. If you can make a sketch or block diagram, it would help greatly.

    1. The receiver always is battery powered and portable, and should fit in a pocket.
    2. The receiver always makes a silent indication, and has an audible indicator with an disable switch.
    3. The receiver should have an internal rechargeable battery and charging circuit.
    4. It would be convenient if the receiver dropped into a charging stand.
    5. A standard non-rechargeable battery is acceptable but not preferred.

    6. There can be multiple transmitters and receivers.
    7. All transmitters all trigger receivers. No addressability.
    8. The transmitter is wired to a switch or is small enough that it has the switch on it.
    9. The transmitter can be either wired to power, but an internal battery is preferred.
    10. If it has a battery it needs to indicate when the battery is low.

    This sounds a lot like a wireless doorbell. There are many varieties on ebay, some with receivers that plug into a wall outlet and some with battery powered receivers. They play loud obnoxious jingles when triggered, but if you get a battery powered one, take out the pc board, an connect it to a cell phone vibrator, I think you have a working prototype for under $20. This requires medium-level expertise in electronics repair and construction.

    The transmitter battery should last years since it makes circuit power only when the button is pressed. The battery in a automotive key fob is good for about 5 years.

    If you need addressability or more range than a wireless doorbell can provide, the next layer is a garage door opener (transmitters and receivers at Home Depot) or an ISM band remote control system (lotsa stuff on ebay).

  3. DanW8KMX

    Thread Starter Member

    Oct 21, 2009
    Hello ak:
    Your No. 6 should be change to "There can be multiple transmitters, up to 3, but only one receiver with a backup if primary receiver fails.
    As to No. 8, the perfect transmitter would be a wireless doorbell button. All remain deductions above are correct.

    Yes, it does sound like a wireless doorbell however I was looking for something commercial that can be replaced if necessary. Example: I can do the mods you suggest but then if I get hit by a bus, there is no person that can maintain or fix the thing. Also, only one button transmitter. I don't know if additional buttons can be purchased that will be coded to the primary receiver. I will check on that. I am sure that the range of the wireless doorbell is sufficient.

    I will go by Home Depot or Lowes today to see what is available.
    Thanks for the info.