Week 9: Output Devices

Trying out the 8x8 Pixel Matrix

Since I want to use an 8x8 Pixel Matrix for my final project I wanted to test it out now.

To test if I can even use it I tried to upload an empty sketch with just

8x8.ino

            #include <Adafruit_LEDBackpack.h>
        

I got the compilation error again, meaning that this library doesn't support the ATTiny45.

Testing a Speaker

Then I tried a speaker. I soldered wires to the speaker so I can connect it to my Board.

I then wrote a simple code that plays a tone from the speaker. Since the speaker needs to vibrate I have to constantly change a value for it to vibrate.

sound.ino

            int i = 0;                      //int for analog value
            bool up = true;                 //bool as switch
            
            void setup() {
                pinMode(A3, OUTPUT);        //speaker pin as output
            }
            
            void loop() {
                if(up){                     
                i++;                        //raise the value
                }else{
                i--;                        //lower the value
                }
                if(i >= 255){
                up = false;                 //flip switch if value is too high
                }
                if(i <=0){
                up = true;                  //flip switch if value is too low
                }
                analogWrite(A3, i);         //write value to speaker pin
            }
        

Demonstration

Downloads

cloud_download Download sound.ino

Using the speaker to spit out tones and melodies

Getting the tone function to work was a lot of hassle. The original ATTiny board manager package I used doesn't support the tone() function which I found out thanks to this Github Issue of a different ATTiny Core Package.

I decided to use this ATTiny Core Package and used this installation guide using the "Boards Manager Installation" method.

After getting a "Access Denied" compilation error I wasted a lot of time not reading the Github Page of the package.

So after reading that I downgraded the AVR board package and got a different error stating that some config files could not be read.

I removed the package using the board manager and used the different method from the installation guide. And to my joy it worked perfectly. The tone() function finally worked.

To finish up this assignment I wrote a melody (that could not be too long since the memory restriction of the ATTiny45). I used this tutorial as a base.

speakerTest.ino
            #include "pitches.h"

            // This array contains all the notes being played in the melody
            int melody[] = { 
              NOTE_E7, NOTE_E7, 0, NOTE_E7,
              0, NOTE_C7, NOTE_E7, 0,
              NOTE_G7, 0, 0,  0,
              NOTE_G6, 0, 0, 0,
             
              NOTE_C7, 0, 0, NOTE_G6,
              0, 0, NOTE_E6, 0,
              0, NOTE_A6, 0, NOTE_B6,
              0, NOTE_AS6, NOTE_A6, 0,
             
              NOTE_G6, NOTE_E7, NOTE_G7,
              NOTE_A7, 0, NOTE_F7, NOTE_G7,
              0, NOTE_E7, 0, NOTE_C7,
              NOTE_D7, NOTE_B6, 0, 0,
            };
            
            // This array contains the lenght of the notes
            int noteDurations[] = {
              12, 12, 12, 12,
              12, 12, 12, 12,
              12, 12, 12, 12,
              12, 12, 12, 12,
             
              12, 12, 12, 12,
              12, 12, 12, 12,
              12, 12, 12, 12,
              12, 12, 12, 12,
             
              9, 9, 9,
              12, 12, 12, 12,
              12, 12, 12, 12,
              12, 12, 12, 12,
            };
            
            void setup() {
              // This for loop goes through all notes in the melody array
              for (int thisNote = 0; thisNote < 8; thisNote++) {
            
                // to calculate the note duration, take one second divided by the note type.
                //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
                int noteDuration = 1000 / noteDurations[thisNote];
                tone(3, melody[thisNote], noteDuration);
            
                // to distinguish the notes, set a minimum time between them.
                // the note's duration + 30% seems to work well:
                int pauseBetweenNotes = noteDuration * 1.30;
                delay(pauseBetweenNotes);
                // stop the tone playing:
                noTone(3);
              }
            }
            
            void loop() {
            }
        

Also be sure to save the pitches.h in the same sketch.

pitches.h
/*************************************************
 * Public Constants
 *************************************************/

#define NOTE_B0  31
#define NOTE_C1  33
#define NOTE_CS1 35
#define NOTE_D1  37
#define NOTE_DS1 39
#define NOTE_E1  41
#define NOTE_F1  44
#define NOTE_FS1 46
#define NOTE_G1  49
#define NOTE_GS1 52
#define NOTE_A1  55
#define NOTE_AS1 58
#define NOTE_B1  62
#define NOTE_C2  65
#define NOTE_CS2 69
#define NOTE_D2  73
#define NOTE_DS2 78
#define NOTE_E2  82
#define NOTE_F2  87
#define NOTE_FS2 93
#define NOTE_G2  98
#define NOTE_GS2 104
#define NOTE_A2  110
#define NOTE_AS2 117
#define NOTE_B2  123
#define NOTE_C3  131
#define NOTE_CS3 139
#define NOTE_D3  147
#define NOTE_DS3 156
#define NOTE_E3  165
#define NOTE_F3  175
#define NOTE_FS3 185
#define NOTE_G3  196
#define NOTE_GS3 208
#define NOTE_A3  220
#define NOTE_AS3 233
#define NOTE_B3  247
#define NOTE_C4  262
#define NOTE_CS4 277
#define NOTE_D4  294
#define NOTE_DS4 311
#define NOTE_E4  330
#define NOTE_F4  349
#define NOTE_FS4 370
#define NOTE_G4  392
#define NOTE_GS4 415
#define NOTE_A4  440
#define NOTE_AS4 466
#define NOTE_B4  494
#define NOTE_C5  523
#define NOTE_CS5 554
#define NOTE_D5  587
#define NOTE_DS5 622
#define NOTE_E5  659
#define NOTE_F5  698
#define NOTE_FS5 740
#define NOTE_G5  784
#define NOTE_GS5 831
#define NOTE_A5  880
#define NOTE_AS5 932
#define NOTE_B5  988
#define NOTE_C6  1047
#define NOTE_CS6 1109
#define NOTE_D6  1175
#define NOTE_DS6 1245
#define NOTE_E6  1319
#define NOTE_F6  1397
#define NOTE_FS6 1480
#define NOTE_G6  1568
#define NOTE_GS6 1661
#define NOTE_A6  1760
#define NOTE_AS6 1865
#define NOTE_B6  1976
#define NOTE_C7  2093
#define NOTE_CS7 2217
#define NOTE_D7  2349
#define NOTE_DS7 2489
#define NOTE_E7  2637
#define NOTE_F7  2794
#define NOTE_FS7 2960
#define NOTE_G7  3136
#define NOTE_GS7 3322
#define NOTE_A7  3520
#define NOTE_AS7 3729
#define NOTE_B7  3951
#define NOTE_C8  4186
#define NOTE_CS8 4435
#define NOTE_D8  4699
#define NOTE_DS8 4978
        

Here is a video of the melody playing

Downloads

cloud_download Download speakerTest.ino

cloud_download Download pitches.h

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