next topic »

[on:]

3 tact switch, 1st pin connected to 23, 24 and 25 while 2nd pin is connected to ground.
8 ohm speaker, negative in ground while positive pin is connected to pin 8.
all components are operational and fine.
i just have problems with the code and i dont know where i got wrong,..   

Code:

#include "pitches.h"

byte button[] = {23, 24, 25};  //create array of buttons connected at pin 23, 24 and 25
byte speakerpin = 8;  //sets speaker pin to pin 8
byte buttonset ;  //variable for reading button push

void setup() {
  // set all pins to output
  pinMode(speakerpin, OUTPUT);
  for(int x=23; x<26; x++) {
    pinMode(button[x] , INPUT);
    digitalWrite(button[x] , HIGH); // buttons are in the high position
 }
 }

void loop(){
for(int x=23; x<26; x++){
  buttonset = digitalRead(button[x]);
   
      if(buttonset == LOW){
         if(x == 23){ // if button on pin 2 is pressed
    //        if (buttonset == LOW){
            tone(8, NOTE_C4);    //stores the note's wavelength to be played.
      //   }
       }
         if(x == 24){
    //        if (buttonset == LOW){
            tone(8, NOTE_D4);
      //   }
       }
         if(x == 25){
     //       if (buttonset == LOW){
            tone(8, NOTE_E4);
      //   }
       }
         else
            noTone(8);
      }
   } 
}

[/size]

[Reply #1 on:]

Code:

  for(int x=23; x<26; x++) {
    pinMode(button[x] , INPUT);

You are referencing the 23rd, 24th, and 25th elements of an array that has 3 elements. Not a good thing.

[Reply #2 on:]

You risk damaging your Arduino connecting an 8 Ohm speaker to it without a series resistor.

[Reply #3 on:]

Code:

You are referencing the 23rd, 24th, and 25th elements of an array that has 3 elements. Not a good thing.

kind sir, can you suggest anything to correct this?

[Reply #4 on:]

can you suggest anything to correct this?

Sure. Use the correct value in the for loop.

You either want to set the pin whose number is x or the pin whose number is in the x position in the array.

For the former, loose the array.

For the latter, the proper range is x=0 to x<3.

[Reply #5 on:]

Code:

You risk damaging your Arduino connecting an 8 Ohm speaker to it without a series resistor.

thank you for the caution sir, i'm kind of new with arduino, my bad.
anyway, my supply is just 5 volts, what resistor value should i use?

[Reply #6 on:]

sir PaulS,

i have my ckt up and running now, thanks for the advice.
this proves my knowledge in C is still lacking, better study more. 

[Reply #7 on:]

Code:

You risk damaging your Arduino connecting an 8 Ohm speaker to it without a series resistor.

thank you for the caution sir, i'm kind of new with arduino, my bad.
anyway, my supply is just 5 volts, what resistor value should i use?

At least a 120 ohms or more to stay below the 40ma absolute maximum current draw limit from an output pin. But keep in mind that means the resistor will 'consume' about 95% of the 'audio power' leaving a wimpy amount of about 13 milliwatts of audio power to drive the the 8 ohm speaker. You should look for a speaker with a much higher voice coil resistance or do as most anyone wanting to drive a 8 ohm speaker, use a audio amplifier stage or module to drive the speaker.

Lefty

[Reply #8 on:]

Code:

At least a 120 ohms or more to stay below the 40ma absolute maximum current draw limit from an output pin. But keep in mind that means the resistor will 'consume' about 95% of the 'audio power' leaving a wimpy amount of about 13 milliwatts of audio power to drive the the 8 ohm speaker. You should look for a speaker with a much higher voice coil resistance or do as most anyone wanting to drive a 8 ohm speaker, use a audio amplifier stage or module to drive the speaker.

thanks for the heads up sir,.. i will research and study about audio amplifier that you mentioned,..