Ian Henderson

Week 13 - Output Devices

Week 13 - Output Devices

16 April 2012 13:40 Monday

Assignment: add an output device to a microcontroller board and program it to do something.

I intend to set up a servo motor which I will run off of an Arduino board. First I will have to build the board. It took me three attempts to mill the board because the traces are so fine and on the first two trials the pulled up. By the 3rd trial my toolbits were slightly dulled, which makes them cut a tiny bit cleaner and kept the traces from pulling up. Unfortunately, I forgot to set the milling machine to cut out any extraneous copper, and so there is excess material on the board, which for me can be confusing. I borrowed Anna's board as a reference, and with a sharpie, I highlighted all the extraneous areas so I would not get confused while soldering. Now I will attempt to put the board together.

16 April 2012 15:06
I have now soldered all of the components onto the Arduino board which is to drive the servo motor. I am using an ATmega328 instead of an ATmega168, so I will have to modify my diver code accordingly.


I have hooked up the Arduino board and the FabISP. I have burned the bootloader. The LED is now blinking.

I have burned the sample program:

/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.
 
  This example code is in the public domain.
 */

void setup() {                
  // initialize the digital pin as an output.
  // Pin 13 has an LED connected on most Arduino boards:
  pinMode(13, OUTPUT);     
}

void loop() {
  digitalWrite(13, HIGH);   // set the LED on
  delay(1000);              // wait for a second
  digitalWrite(13, LOW);    // set the LED off
  delay(1000);              // wait for a second
}

// Sweep
// by BARRAGAN  
// This example code is in the public domain.


#include  
 
Servo myservo;  // create servo object to control a servo 
                // a maximum of eight servo objects can be created 
 
int pos = 0;    // variable to store the servo position 
 
void setup() 
{ 
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object 
} 
 
 
void loop() 
{ 
  for(pos = 0; pos < 180; pos += 1)  // goes from 0 degrees to 180 degrees 
  {                                  // in steps of 1 degree 
    myservo.write(pos);              // tell servo to go to position in variable 'pos' 
    delay(15);                       // waits 15ms for the servo to reach the position 
  } 
  for(pos = 180; pos>=1; pos-=1)     // goes from 180 degrees to 0 degrees 
  {                                
    myservo.write(pos);              // tell servo to go to position in variable 'pos' 
    delay(15);                       // waits 15ms for the servo to reach the position 
  } 
}