New project! First, here’s a video:

This is the proof of concept for the volume control of the speaker system. In it’s final form, this sensor will be exposed to the outside and will allow users to control the volume without opening the system, preserving the fidelity of the inside. For example, imagine a user is at the beach and wants to change the volume but they have sand covered hands or wet hands. This system will solve that problem.

The sensor is the Sharp GP2Y0A41SK0F. Here are some very very macro shots of sensors inner workings.

But now for what you came here for, the code. It’s very poorly commented as this is just a prototype, but it’s better than nothing. As this project progresses I’ll posted updated versions of this code.

This demo also relies heavily this shift register. I still haven’t decided if i’m going to use a buzzer to interact with the user or if I’m going to use these bar graphs.

int SER_Pin = 10;   //pin 14 on the 75HC595
int RCLK_Pin = 11;  //pin 12 on the 75HC595
int SRCLK_Pin = 12; //pin 11 on the 75HC595

//How many of the shift registers - change this
#define number_of_74hc595s 4 

//do not touch
#define numOfRegisterPins number_of_74hc595s * 8

boolean registers[numOfRegisterPins];

int detect_led = 2;

int setlevelMode0_led = 3;
int setlevelMode1_led = 4;
int setlevelMode2_led = 5;

int seeking_led = 6;

int check_val = 8;

void setup(){
  pinMode(SER_Pin, OUTPUT);
  pinMode(RCLK_Pin, OUTPUT);
  pinMode(SRCLK_Pin, OUTPUT);
  //reset all register pins
  clearRegisters();
  writeRegisters();

  pinMode(detect_led, OUTPUT);

  pinMode(setlevelMode0_led, OUTPUT);
  pinMode(setlevelMode1_led, OUTPUT);
  pinMode(setlevelMode2_led, OUTPUT);

  pinMode(seeking_led, OUTPUT);

  Serial.begin(9600);
}

int prelevel_0 = 0;
int prelevel_1 = 0;
int prelevel_2 = 0;
int prelevel_3 = 0;
int prelevel_4 = 0;
int prelevel_5 = 0;
int prelevel_6 = 0;
int prelevel_7 = 0;
int prelevel_8 = 0;
int prelevel_9 = 0;

int pre_positions[10] = {prelevel_0, prelevel_1, prelevel_2, prelevel_3, prelevel_4, prelevel_5, prelevel_6, prelevel_7, prelevel_8, prelevel_9};

void loop(){
  for(int i = 0; i <= 9; i = i + 1){
    writebargraph(0,map(analogRead(0),20,600,0,9));
    pre_positions[i] = map(analogRead(0),20,600,0,9);
    if(pre_positions[i] == check_val){
      Serial.println("Check Detected");
      digitalWrite(detect_led, HIGH);
    }
    else {
     digitalWrite(detect_led, LOW);
    }
    delay(30);
  }
  for(int i = 0; i <= 9; i = i + 1){
    Serial.print(pre_positions[i]);
    Serial.print(",");
  } 

  if (pre_positions[0] == check_val && pre_positions[1] == check_val && pre_positions[2] == check_val && pre_positions[3] == check_val && pre_positions[4] == check_val && pre_positions[5] == check_val && pre_positions[6] == check_val && pre_positions[7] == check_val && pre_positions[8] == check_val && pre_positions[9] == check_val  ){
    Serial.print(" - Pre Level Set");
    Serial.println("");
    delay(500);
    setlevel();
    delay(500);
  }
  else {
    Serial.println(" - No Set");
  }

}

//set all register pins to LOW
void clearRegisters(){
  for(int i = numOfRegisterPins - 1; i >=  0; i--){
     registers[i] = LOW;
  }
} 

//Set and display registers
//Only call AFTER all values are set how you would like (slow otherwise)
void writeRegisters(){
  digitalWrite(RCLK_Pin, LOW);
  for(int i = numOfRegisterPins - 1; i >=  0; i--){
    digitalWrite(SRCLK_Pin, LOW);
    int val = registers[i];
    digitalWrite(SER_Pin, val);
    digitalWrite(SRCLK_Pin, HIGH);
  }
  digitalWrite(RCLK_Pin, HIGH);
}

//set an individual pin HIGH or LOW
void setRegisterPin(int index, int value){
  registers[index] = value;
}

void writebargraph(int set, int led){
  if(set == 0){
    for(int i = 0; i <= 9; i = i + 1){
      if(i <= led){

        setRegisterPin(i, HIGH);
        writeRegisters();
      }
      else if(i > led){

        setRegisterPin(i, LOW);
        writeRegisters();
      }
     }
   }
  if(set == 1){
    for(int k = 10; k <= 29; k = k + 1){
      if(k <= 10 + led){
        setRegisterPin(k, HIGH);
        writeRegisters();
      }
      else if(k > 10 + led){
        setRegisterPin(k, LOW);
        writeRegisters();
      }
    }
  }

}

void setlevel(){

  int level0 = 0;
  int level1 = 0;
  int level2 = 0;
  int level3 = 0;
  int level4 = 0;
  int level5 = 0;
  int level6 = 0;
  int level7 = 0;
  int level8 = 0;
  int level9 = 0;
  int level10 = 0;
  int level11 = 0;
  int level12 = 0;
  int level13 = 0;
  int level14 = 0;
  int level15 = 0;
  int level16 = 0;
  int level17 = 0;
  int level18 = 0;
  int level19 = 0;
  int level20 = 0;
  int level21 = 0;
  int level22 = 0;
  int level23 = 0;
  int level24 = 0;
  int level25 = 0;
  int level26 = 0;
  int level27 = 0;
  int level28 = 0;
  int level29 = 0;

  int positions[30] = { level0, level1, level2, level3, level4, level5, level6, level7, level8, level9, level10, level11, level12, level13, level14, level15, level16, level17, level18, level19, level20, level21, level22, level23, level24, level25, level26, level27, level28, level29};

  digitalWrite(setlevelMode1_led, LOW);
  digitalWrite(setlevelMode2_led, LOW);  

  boolean seeking = true;

  while(seeking == true){
    for(int i = 0; i <= 29; i = i + 1){
      writebargraph(1,map(analogRead(0),20,600,0,19));
      positions[i] = map(analogRead(0),20,600,0,19);
      Serial.print(positions[i]);
      Serial.print(",");
      delay(10);
    }  

  if (positions[0] == positions[0] && positions[1] == positions[0] && positions[2] == positions[0] && positions[3] == positions[0] && positions[4] == positions[0] && positions[5] == positions[0] && positions[6] == positions[0] && positions[7] == positions[0] && positions[8] == positions[0] && positions[9] == positions[0] && positions[10] == positions[0] && positions[11] == positions[0] && positions[12] == positions[0] && positions[13] == positions[0] && positions[14] == positions[0] && positions[15] == positions[0]  ){
     Serial.print(" - Level Set");
     digitalWrite(setlevelMode1_led, HIGH);
     seeking = false;
   }

   else {
     Serial.print(" - No Set");
     digitalWrite(setlevelMode1_led, LOW);
   }

   Serial.println("");

  }

}

Here are some photos of the board if you want to try and work out the schematic: