Objective

Integrate the units into one project.

Design ideas

I wanted knew that I would not be able to complete the project I initially proposed. I decided to built a cat toy/house instead. At the moment my cat lives in a cardboard box:

cat

I wanted to make him a new house that would also entertain him. The step into the house should have a touch sensor, this sensor will trigger some kind of cat toy. I had a few ideas for the cat toy part:

A while back, I found a project where a servo motor was used to move a ping pong ball. I decided to test, whether I coudl use a motor+ball combination to build my cat toy.

I wanted to make sure that I had a firm grasp (haha) of all the skills I needed for my final project before tackling everything at once:

House

electrodes2

I modeled a quick mock up of the design of the house in blender (make sure to turn on cycles render for rendering). Based on this design, I then used Rhino to make profile cuts for milling:

electrodes2

I added dog bone shaped fillets to all the inside corner of joints using the "Fillets" tool in the shopbot software (0.25in endmill, 10000rpm spindle speed, 90in/min feed rate, 40in/min plugne rate). I used the shopbot to mill the pieces out of birch plywood ($40 for a 4x8 feet piece from home depot). Make sure to do small, internal cuts first and then cut out the bigger shapes around them. Milling took around 30min overall.

electrodes2
electrodes2

The bottom of the cuts came out lookin quite rough, I sanded down the edges by hand:

electrodes2

The pieces are held together by wood glue and wood screws (seems to be very stable).

Cat toy

I cut open a tennis ball with a utility knife (the tennis ball was clamped down! Don't hurt yourself!) and glued down the servo motor inside. This resulted in only a very small wobble. For a bigger wobble, the rotation of the servo motor should move the center of mass of the tennis ball. I tried to achieve this by adding weights (scrap metal) to the bottom of the ball and to the side of the servo motor:

electrodes2

Programming

I started with my capacitive touch board from week 9: The functionalities I included are:

For programming, I combined my code from the inputs and the ouputs week: 

//                        attiny85
//                   reset -+---+- power
// (on while touching) pb3 -+*  +- pb2 (toggled by touch)
//       (touch input) pb4 -+   +- pb1 (fading while touching)
//                  ground -+---+- pb0 (fading always)


//                        attiny44
//                      power -+---+- GND
//                  10 -  pb0 -+*  +- pa0 -0
//                     9 -pb1 -+   +- pa1 - 1
//                 reset -pb3 -+---+- pa2 -2
//                     8 -pb2 -+*  +- pa3 -3
//                     7 -pa7 -+   +- pa4 -4
//                     6 -pa6 -+---+- pa5 -5



int servo = 6; 
int calibration = 0;
int previous;
int tPulse        = 4000;         // Total pulse length on 1 Mhz clock 
int hPulse        =   60;         // High pulse time (60=0deg -> 280=180deg)
bool Dir          =    1;         // servo direction
int randomval = 0;
int fadeval = 0, fadestep = 1;
int val = 0; //define button state
int lastval = 0; //define button state
int counter = 0;
int counter2 = 0;
const int button = 8; //pin with the button, duh





void setup()
{

  pinMode(servo, OUTPUT);
  pinMode(button, INPUT_PULLUP); 
  delay(100);
  //calibration to find out what the pin looks like when you don't touch it
  for (int i = 0; i < 20; i++) {
    calibration += chargeTime(PA3);
    delay(20);
  }
  //+4 to round correctly
  calibration = (calibration + 4) / 20;
}





void loop()
{
//button code
  val = digitalRead(button);
   
   
   if (val == LOW && lastval == HIGH) {

    while (counter <= 500){
      
    
  digitalWrite(servo, HIGH);                // Set pin high to start pulse
  delayMicroseconds(hPulse);                // High pulse angle data   
  digitalWrite(servo,LOW);                  // Set low for the rest of pulse
  delayMicroseconds(tPulse-hPulse);
  
  if (hPulse < 280 && Dir == 1) hPulse+=10; // Rotate servo to 180 degrees
  else if (hPulse >= 280 && Dir == 1){      // servo hit upper limit
    hPulse = 280;                           // Keep servo angle in bounds
    Dir=!Dir;                               // Switch direction
  }
  if (hPulse > 60 && Dir == 0) hPulse-=10;  // Rotate servo to 0 degrees
  else if (hPulse <= 60 && Dir == 0){       // servo hit lower limit
    hPulse = 60;                            // Keep servo angle in bounds
    Dir=!Dir;                               // switch direction
  }
  delayMicroseconds(500); // Give servo some time to move before giving it a new position
 counter++; 
      }

    }

     
   else {

     digitalWrite(servo, LOW); 


}
counter = 0;
lastval = val;




  
  //capactive touch code:
  
  int n = chargeTime(PA3);
  
  if (n > calibration) {

    while (counter2 <= 50){
      
    
  digitalWrite(servo, HIGH);                // Set pin high to start pulse
  delayMicroseconds(hPulse);                // High pulse angle data   
  digitalWrite(servo,LOW);                  // Set low for the rest of pulse
  delayMicroseconds(tPulse-hPulse);
  
  if (hPulse < 280 && Dir == 1) hPulse+=10; // Rotate servo to 180 degrees
  else if (hPulse >= 280 && Dir == 1){      // servo hit upper limit
    hPulse = 280;                           // Keep servo angle in bounds
    Dir=!Dir;                               // Switch direction
  }
  if (hPulse > 60 && Dir == 0) hPulse-=10;  // Rotate servo to 0 degrees
  else if (hPulse <= 60 && Dir == 0){       // servo hit lower limit
    hPulse = 60;                            // Keep servo angle in bounds
    Dir=!Dir;                               // switch direction
  }
  delayMicroseconds(500); // Give servo some time to move before giving it a new position
 counter2++; 
      }
      
    }

     
   else {

     digitalWrite(servo, LOW); 


}
previous = n;
counter2 = 0;  
  delayMicroseconds(500);
}
//this gives you the charge time of the pin that you touch
byte chargeTime(byte pin)
{
  byte mask = (1 << pin);
  byte i;

  DDRA &= ~mask; // input
  PORTA |= mask; // pull-up on

  for (i = 0; i < 16; i++) {
    if (PINA & mask) break;
  }

  PORTA &= ~mask; // pull-up off
  DDRA |= mask; // discharge

  return i;
}
//                        attiny85 //                   reset -+---+- power // (on while touching) pb3 -+*  +- pb2 (toggled by touch) //       (touch input) pb4 -+   +- pb1 (fading while touching) //                  ground -+---+- pb0 (fading always) //                        attiny44 //                      power -+---+- GND //                  10 -  pb0 -+*  +- pa0 -0 //                     9 -pb1 -+   +- pa1 - 1 //                 reset -pb3 -+---+- pa2 -2 //                     8 -pb2 -+*  +- pa3 -3 //                     7 -pa7 -+   +- pa4 -4 //                     6 -pa6 -+---+- pa5 -5 //Define constants: const int button = 8; //pin with the button, duh const int LED = 2; //pin with the LED int val = 0; //define button state void setup() {  // put your setup code here, to run once: pinMode(button, INPUT_PULLUP); //use the internal pullup of the microprocessor pinMode(LED, OUTPUT); //LED pin will be our output pin } void loop() {  // put your main code here, to run repeatedly: val = digitalRead(button);   if (val == LOW) {     digitalWrite(LED, LOW);     delay (100) ; // 100 microsecond delay     digitalWrite(LED, HIGH); // puts 5V on the LED pin     delay (100);          digitalWrite(LED, LOW);     delay (100) ;     digitalWrite(LED, HIGH);     delay (100);   }   else {     digitalWrite(LED, HIGH);   }   }

I cut a second touch sensor from copper foil using the vinyl cutter (also see week 9) and transfered it to the step of the house:

electrodes2

The power supply consists of three AAA batteries (1.5Veach) in sequence to supply 4.5V to the board (test the voltage that the batteries output with a multimeter).

electrodes2

Putting it all together

The cat toy attached to the house with touch sensor and button:

Potential improvements to project: