Project 7 - Keyboard Instrument not working, please help!

Projects General Guidance
1

Hey Guys,

I am just starting out with Arduino and working through the project book so I am pretty green at the moment. Please excuse any ignorance! :slight_smile:

I am having trouble with a number of projects, but lately I can't get Project 7 - Keyboard Instrument to work, at all.

I am not sure where I am going wrong, I have followed all the steps in the wiring diagram and code. But I'll post pictures of both.

I do have trouble grasping some concepts, but particularly selecting the right resistor - as I struggle to read and identify them correctly.

Any help will be appreciated!

IMG_20251229_205225
IMG_20251229_2052251920×1440 425 KB

int notes[] = { 262, 294, 330, 349 };
void setup() {
  Serial.begin(9600);
}
void loop() {
  int keyVal = analogRead(A0);
  Serial.println(keyVal);
  if (keyVal == 1023) {
    tone(8, notes[0]);
  } else if (keyVal >= 990 && keyVal <= 1010) {
    tone(8, notes[1]);
  } else if (keyVal >= 505 && keyVal <= 515) {
    tone(8, notes[2]);
  } else if (keyVal >= 5 && keyVal <= 10) {
    tone(8, notes[3]);
  } else {
    noTone(8);
  }
}
2

Find out how those buttons work. Connecting diagonally is often used…

3

Does your circuit layout ('schematic') look like this?

Project07-StarterKit_PossibleSchematic
Project07-StarterKit_PossibleSchematic698×525 29.1 KB

EDIT: 30/12/25

No reply yet, but if it’s ‘Yes’ then, like several I’ve seen it’s wrong. Try this correct version;

Project07StarterKit_KeyboardSchemetic_Drago
Project07StarterKit_KeyboardSchemetic_Drago1061×683 46.4 KB

4

  • Confirm the A0 voltages when switches are pressed.
    Use a voltmeter to measure the voltages.

  • Write diagnostic code that always output a 3000Hz tone to pin 8.

5

image
image405×693 70.4 KB

From the top:
10000/(10000+0) * 1023 ~= 1023

10000/(10000+1000) * 1023 ~= 930

10000/(10000+10000) * 1023 ~= 511

10000/(10000+470) * 1023 ~= 970

If I've read those resistor values correctly, the ADC values obtained are outside your range checks, except for the 10K + 10K button (second from bottom) and the 10K + 0 button (top). Therefore, you should get sound from those two only.

Edit: and if there's any resistance at all in your connection to the breadboard's power rail and the top button, you won't get any sound out of that one.

Edit again: and if the 10K resistors fall at the extreme ends of their tolerance (one high and one low), you may not get anything out of the second from button button either as the ADC value could go as high as 516.