+ Post New Thread
Results 1 to 3 of 3
  1. #1
    Newbie level 1
    Points: 26, Level: 1
    lauracastellana's Avatar
    Join Date
    Aug 2019
    0 / 0

    Keypad playing sounds - Recommendation for design

    Hello everyone!
    This is my first message in this forum and I really appreciate your help.

    I want to design a gadget for my uncle who can not speak, just move her fingers. As I don't have an electronic profile (i am software developer), I am asking you for assistance in order to design the best cost-effective solution for this idea

    Functionality: A keypad (colorful) that can play sounds associated with their own keys.

    *Speaker - Q1. As the gadget probably will go on a wheelchair, it should be a rectangle (not too high). Where can I find it? Q2. What are the main characteristics of a speaker? What potency? Vats?. It has to be enough strong to let her communicate in the street. I do not know how to measure it.
    *Mp3 player - Q3. Is it required? or maybe it has to be integrated with the PCB/microprocessor?
    *Microproccesor/PCB - Q4. I know abut raspberry, elegoo and Arduino. However, I think these are overpowered for the simple functionallity to receive an order from the keyboard and play a sound. Maybe they consume more energy? What is your recommendation for this component?
    *Keyboard - Q5 It has to be something like a matrix keypad but with color in the keys. I have not found anything on aliexpress related to a full matrix 3x3 or 4x4 with colors. I have found only normal keyboards with numbers. Maybe buy the keys separately and with their custom color?
    *Battery. A thin battery. Q6. Will you design using standard batteries or use external battery than can be recharged with energy/power. Q7. What power is required for this design taking into account the gadget should be located on the arm of the wheelchair (it can not be so big).
    *Case. Q8. Would you buy a standard box case and after receive it make some customization to place the keyboard and the battery connection charger? Q9. If it is a custom case, where will you get it? I will design it using SketchUp or some software in order to send it someplace.

    Additional questions:
    Q10. Is it my design correctly? Or will you recommend something else? A new better design idea?
    Q11. Any cheap place to buy those components if I have to buy it for more people (to make between 30-50 gadgets for the nursing home)?
    Q12. What is the cost per component you estimated?

    Thank you a lot! Feel free to ask whatever you want.

    •   AltAdvertisement


  2. #2
    Advanced Member level 5
    Points: 23,780, Level: 37
    barry's Avatar
    Join Date
    Mar 2005
    California, USA
    1003 / 1003

    Re: Keypad playing sounds - Recommendation for design

    Questions for you:

    1) what kind of “sounds”do you want this to make? You don’t need MP3 to make beeps.
    2) How long do you want the battery to last? THAT will determine the size.
    3) do you want to do your own electronic design, Pcb layout, procurement, assembly, testing, debugging, or do you want to pay a small amount of money for an Arduino?

    Even if you get a “standard” case, you’re still going to have to customize it, so it’s not a standard case anymore. Do you want to do the work? Search the internet for cases. Plastic, metal, whatever.

    •   AltAdvertisement


  3. #3
    Super Moderator
    Points: 80,462, Level: 69
    7 years registered
    2nd Helpful Member
    betwixt's Avatar
    Join Date
    Jul 2009
    Aberdyfi, West Wales, UK
    4403 / 4403

    Re: Keypad playing sounds - Recommendation for design

    I agree with Barry, you need to give us a little more information.

    How many keys do you need, to some extent that decides the kind of keypad you need?
    Are the sounds complex (like chimes/ringing/something recorded) or just plain beeps at different pitches?
    Does a key press produce just one sound when held down or should there be a sequence of sounds triggered by a single press?
    The biggest single item in the enclosure will probably be the loudspeaker, how loud does it have to be?

    As for colors, I use cheap 4x4 membrane keypads like these:https://www.ebay.co.uk/itm/4x4-16-ke...AAAOSw2BFdKFdh
    then use a color laser printer (inkjet works just as well) on a sticky packaging label to make an overlay for them so they look like this:
    Click image for larger version. 

Name:	20190814_165008.jpg 
Views:	4 
Size:	51.5 KB 
ID:	154968
    Finally, I aerosol spray the label with a fixer, the kind you use on inkjet prints to make them glossy and more durable. The one in the photograph has had about five years use.

    PLEASE - no friends requests or private emails, I simply don't have time to reply to them all.
    It's better to share your questions and answers on Edaboard so we can all benefit from each others experiences.

--[[ ]]--