10. Wearables

November 23rd, 2020

Liza Stark

This second class on the topic of wearables and e-textiles will provide a more advanced coverage on soft sensors and actuators and programming interactions

Research

Useful links

[mosfet and transistor dronwbotworkshop] (https://www.youtube.com/watch?v=IG5vw6P9iY4)

(Capítulo 45 - MOSFET IRF520N módulo transistor de potencia (y PWM)) [https://www.youtube.com/watch?v=SliUieh2eVc]

Tutorial Activities

Program Attiny 85

In order to prorgam the Attiny 85, I first required a couple of things: * Attiny85 * Arduino Uno * 1o uf Capacitor * led * 220 ohm Resistance

1.1 Setup In this case I followed the Tutorial on programming attiny Recomended, as well as look over the tutorial on the fabclass. I also found the following article usefull as a general purpose article to better undersatnd what is going on. [Arduino as ISP and Arduino Bootloaders] (https://www.arduino.cc/en/Tutorial/BuiltInExamples/ArduinoISP).

1.2 Upload the code In this instance I uploaded the blink code to test out. * The library of the attiny85 was installed * The parameters to fit the specifically attiny 85 as follows:

• The programming itself is as follows. The standard Blink example with the led pin changed to '0'.

  // the setup function runs once when you press reset or power the board
  void setup() {
    // initialize digital pin LED_BUILTIN as an output.
    pinMode(0, OUTPUT);
  }
  
  // the loop function runs over and over again forever
  void loop() {
    digitalWrite(0, HIGH);   // turn the LED on (HIGH is the voltage level)
    delay(1000);                       // wait for a second
    digitalWrite(0, LOW);    // turn the LED off by making the voltage LOW
    delay(1000);                       // wait for a second
  }
  

• Referencial Diagram of Pinout of the Attiny 85:

The end result, for simplicity I decided to use a cr2032 in the breadboard.

TA-w10-1 from mr.jsnap on Vimeo.

Undestanding Mosfets

• We saw this part in the tutorial of the week, so I wont go into too much detail. In this case I used the irf520 Mosfet. It is an N-channel Mosfet. Further information is found the IRF520 Datasheet

Apllication of Mosfet: High power LED

In this case I decided to use:
* High Intensity LED * 9 v battery for The high intensity LED * 4 AAA Batteries to Power the Attiny, Connected in parallel to create a total volt of 6v, Attiny works up to 5.5v * 10k ohm resistor * Diode for High Intensity LED * Attiny 85, with basic "blink code" * The connection was follows: The code used is:

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(2, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  analogWrite(2, 255);   // turn the LED on (255 is the voltage level)
  delay(1000);                       // wait for a second
  analogWrite(2, 0);    // turn the LED off by making the voltage 0
  delay(1000);                       // wait for a second
}

The final result is as follows:

ta-w10-21 from mr.jsnap on Vimeo.

The final goal was to make the entire circuit independent so it works on portable power alone. With this we can test it with the swatches.

1. Swatch: One input and one Output. The following is a setup, using a similar setup as before. The great difference is I am using the previously done soft sensor and a pull up input.
2. the led will change from off to midway on, to full On.
3. The input pullup pin is pin 1

int sw_pin = 1;
int conutner_reset = 3; //how many times we press before we reset

int led_pin = 0; // pin of the led

//variables will change:
int coutner = 0;
int sw_status = 0;
int last_sw_status = 1;


void setup() {
  // initialize input and output pin:
  pinMode(sw_pin, INPUT_PULLUP);
  pinMode(led_pin, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  sw_status = digitalRead(sw_pin);

  //compare the switch to its previous state
  if(sw_status != last_sw_status){

    if(sw_status == HIGH){
      coutner = coutner + 1 ;
    }
      delay(10);
  }


  last_sw_status = sw_status;

  if (coutner == conutner_reset){
    coutner = 0; // set the counter to zero again
  }

  if(coutner == 0){
    analogWrite(led_pin, 0); //led is off
  } else if(coutner == 1){
    analogWrite(led_pin, 50);//led is on half way
    delay(100);
  } else if(coutner == 2){.
    analogWrite(led_pin, 255); //led is full on
    }

  }

ta-w10-3 from mr.jsnap on Vimeo.

Generate Sound

Generate Sound with Arduino

In this case, we used:
- IRF520 Mosfet
- 9v battery
- 3w Speaker
- Arduino
Along with the tutorial reviewed in class.

The code:

const int speaker = 3; //buzzer to arduino pin 8
void setup() {
  pinMode(speaker, OUTPUT); // Set buzzer - pin 8 as an Output
}

void loop() {
  tone(speaker, 1000); //send 1khx dounf signal
  delay(1000);
  noTone(speaker);
  delay(1000);
}

The final Result was as follows:

Play Music of Device on Speaker

The same excersice was done as with the arduino, with the modification of using a 1.8mm White Swade leather. The conductive thread was sawn with machine on top, and the speaker used 3 20mm round Rare earth magnets, two under the speaker and one to hold the other two in place. as follows:

What became interesting is by folding the swade on itself it actually becomes the tension in order to create sound.

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Last update: February 23, 2021