Keypad playing sounds - Recommendation for design

[lauracastellana]

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.

Idea-components:
*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.

 

[barry]

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.

 

[betwixt]

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-k...775430&hash=item3d70d80c8b:g:JcAAAOSw2BFdKFdh
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:

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.

Brian.

 

[lauracastellana]

Thank you. My comments below:

Questions for you:

1) what kind of “sounds”do you want this to make? You don’t need MP3 to make beeps. Play phrases like Hello / Yes / No ...
2) How long do you want the battery to last? THAT will determine the size. The maximum duration for a good price. Let me explain it: if the battery cost 10€ and lives for 1 day but I have other option that will long 4 days for 12€ I will go for it.
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? No, I do not want to design the electronics, only the connections between the components).

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. I think I will use a 3D printer.

 

[lauracastellana]

My comments below. Thanks!

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? 3x3 or 4x4 (2 models)
Are the sounds complex (like chimes/ringing/something recorded) or just plain beeps at different pitches? The sounds are phrases (hello, how are you?)
Does a key press produce just one sound when held down or should there be a sequence of sounds triggered by a single press? One sound.
The biggest single item in the enclosure will probably be the loudspeaker, how loud does it have to be? How can i measure it? (5 meters without distorsion)

As for colors, I use cheap 4x4 membrane keypads like these:https://www.ebay.co.uk/itm/4x4-16-k...775430&hash=item3d70d80c8b:g:JcAAAOSw2BFdKFdh
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:
View attachment 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.
Regarding the keypad, I do not think the membrane keypad will be a good option for an old lady (better buttons).

Brian.