Is it possible to make Capacitive touch operated tone generation with a microcontroller?

[nishy555]

Hello… Im a mechanical engineer & product designer from india.....Im trying to make a project....for that I need TO produce continuous tone at 6 different frequencies (between 17000hz to20000hz) or (between 20000hz to 260000hz) from single sounder/buzzer. And these 6 frequencies should be operated with 6 capacitive touch points. When ever I touch one of these buttons specific frequency should produce….Can anybody please clear my doubts….


1) Is using microcontroller is my best choice? (Presently im using 555 timers in astable mode to produce specific frequency with 6 Toggle switches.

2) Is it possible to produce a continuous tone at specific frequency with line of code using microcontroller? Im working around 20k frequency….Most of the micro controllers working speed is several Megahertz does this produce tone brakes or any other problem?

3) How many pins & bits microcontroller im going to need?

4) What is the smallest & least power consuming microcontroller I can use?

 

[BobK]

1) yes.
2) yes, if you only need a square wave, any micro could do it. If you need to produce another waveform, you might need a more capable one.
3) You would want a micro with 6 capacitive touch inputs and at least 1 output,

A PIC 16F1705 seems to fit the bill. It is a 14 pin chip with 8 cap touch inputs. 32MHz max speed. And costs $1.15 in single quantity.

http://www.microchip.com/wwwproducts/Devices.aspx?product=PIC16F1705

Bob

 

[nishy555]

1) yes.
2) yes, if you only need a square wave, any micro could do it. If you need to produce another waveform, you might need a more capable one.
3) You would want a micro with 6 capacitive touch inputs and at least 1 output,

A PIC 16F1705 seems to fit the bill. It is a 14 pin chip with 8 cap touch inputs. 32MHz max speed. And costs $1.15 in single quantity.

http://www.microchip.com/wwwproducts/Devices.aspx?product=PIC16F1705

Bob

Thanks a lot for your help.... basically im a product designer(http://www.nishanth.me/home.html) i hardly know about electronics...... Can you imagine how much time it will take to make this for a beginner?? Can i find any related tutorials? or any related projects on web? or it is it better to go for a freelancer? How much should i offer for a freelancer?(I really don't know how hard is this thing to make) i wnat to make this within a month....Please suggest me anything help full....

 

[jayanthd]

Hi nishy

Do you want to product square wave or pulses ? If pulses then PWM module of PIC microcontroller can be used to generate it. If square wave then Timer interrupt can be used to toggle a IO pin at the required frequency. As you only need to generate one frequency at a time you can use any 14 PIN PIC microcontroller but only if you need capacitive touch sensing. If you can use buttons then I can write you a code which needs only 1 pin for the 6 buttons. I will use ADC for detecting which button was pressed and one IO pin for generating square wave. So, I can do it with a 8 pin PIC12F microcontroller.