ATTiny85 – Tutorial 9 – Making Sounds

While this looked like a fairly simple tutorial on the face of it, it was actually a bit more difficult.

The main problem that I encountered was that the tone() function is not supported by the ATTiny85 core, so I had to do a bit of hunting around to find an equivalent method for the ATTiny85. As I expected, others had come across this same problem and had already developed a solution for it.

Two of the solutions that I tried (arduino-tiny library and a beep function) were both unsuccessful. Both produced cricket sounds (probably because the timing was wrong). However, I found Simple Tones for ATtiny that produces a nice scale and didn’t cause me too many other problems.

The connection from the ATTiny85 to the Piezo is very simple. Connect Pin 1 of the ATTiny85 to either pin of the piezo (it isn’t polarised). Connect GND to the other pin of the piezo.

Here is the sketch from the Technoblogy article referred to above (Simple Tones for ATTiny).

/* TinyTone for ATtiny85 */

// Notes
const int Note_C  = 239;
const int Note_CS = 225;
const int Note_D  = 213;
const int Note_DS = 201;
const int Note_E  = 190;
const int Note_F  = 179;
const int Note_FS = 169;
const int Note_G  = 159;
const int Note_GS = 150;
const int Note_A  = 142;
const int Note_AS = 134;
const int Note_B  = 127;

int Speaker = 1;

void setup()
{
  pinMode(Speaker, OUTPUT);
}

void loop()
{
  playTune();
  delay(300);
}

void TinyTone(unsigned char divisor, unsigned char octave, unsigned long duration)
{
  TCCR1 = 0x90 | (8-octave); // for 1MHz clock
  // TCCR1 = 0x90 | (11-octave); // for 8MHz clock
  OCR1C = divisor-1;         // set the OCR
  delay(duration);
  TCCR1 = 0x90;              // stop the counter
}

// Play a scale
void playTune(void)
{
TinyTone(Note_C, 4, 500);
TinyTone(Note_D, 4, 500);
TinyTone(Note_E, 4, 500);
TinyTone(Note_F, 4, 500);
TinyTone(Note_G, 4, 500);
TinyTone(Note_A, 4, 500);
TinyTone(Note_B, 4, 500);
TinyTone(Note_C, 5, 500);
}

This sketch works just dandy, straight out of the box. Nice work Technoblogy, nice work indeed.

I need to do some more research to find out how I can get the tone() function from the arduino-tiny library to work satisfactorily, but for now, the above sketch serves my purpose.

Making Sounds with Piezo and the ATTiny85

Well, that concludes Tutorial 9. Enjoy. Once again, 9V to 5V Regulator and ATTiny85 ICSP were used to make this tutorial circuit.

Check out the rest of the tutorials here.