Archive for February, 2003

Drawing Machine #14

Tuesday, February 25th, 2003
This is a sort of meditation inspired by the etchasketch.

Date: Fri, 21 Feb 2003 16:17:06 -0800 (PST)
From: D. Delmar Davis <feurig@fromhell.com>
To: D*** S********* <girlfriend@fromhell.com>
Subject: Re: click click

On Fri, 21 Feb 2003, D*** S******** wrote:

> so what's inside an etchasketch?
> i've always wanted to know!
>

Aluminum powder and plastic pellets the size off a pin in diameter (~1mm). which ohio art swears is non toxic (I trilled holes and vacumed as much as possible out before making a big hole in the back.

There is also a pully system (which I think I reassembled correctly). I have a diagram of it at.

Drawing Machine #13

Saturday, February 8th, 2003
This is the second attempt to write the AVR code based on a technique based on the autonomous vehicle project described at http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s1999/gurnee/index.htm

Code

/*---------------------------------------------------------------------------------13.c

    $Revision: 1.2 $
    Author:     Donald Delmar Davis
    Date:      08feb03
    Purpose:   port of sketchy to avrgcc.
    Credits:    AVR-GCC test program #4 (Author: Volker Oth) / Autonomous car program.

*/
//#if defined (__ATmega163__)
//#define __AVR_ATmega163__ 1
#define __AVR_ATmega8__ 1
//#endif

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/signal.h>

#define ETRIM -200
#define STRIM -100

#define F_CPU            8000000      /* 8Mhz */
#define PULSESPACE	 0xFFFF - 20000

#define PULSECENTER	 (1900 + PULSESPACE)

#define SDLY(DEG)	(1000+(11*(DEG))+PULSESPACE)
#define EDLY(DEG)	(1000+(10*(DEG))+PULSESPACE)

#ifdef __AVR_AT_Mega8__
/* switch defines for dt107 */
#define	SERVOPORTPINS	 PORTB
#define	SERVOPORTDDR	 DDRB
#define E_SERVO		 PINB1
#define S_SERVO		 PINB2
#else
/* switch defines for sim100 */
#define	SERVOPORTPINS	 PORTB
#define	SERVOPORTDDR	 DDRB
#define E_SERVO		 PINB1
#define S_SERVO		 PINB0
#endif

//#define UART_BAUD_RATE      9600      /* 9600 baud */
//#define UART_BAUD_SELECT (F_CPU/(UART_BAUD_RATE*16l)-1)

typedef unsigned char  u08;
typedef          char  s08;
typedef unsigned short u16;
typedef          short s16;

typedef struct _todolist {
	u16 shoulder;
	u16 elbow;
	u16  duration;
	struct _todolist *next;
} todolist;

/* uart globals */
static volatile u08 *uart_data_ptr;
static volatile u08 uart_counter;

unsigned char led;
static volatile u16 sservo,eservo;
static volatile u16 duration;

static volatile todolist stufftodo[]={

  { SDLY(-50), EDLY(0), 2500, (todolist *) &(stufftodo[4]) }, /* when right front hits back right tire */
  { SDLY(0), EDLY(-50), 2500, (todolist *) &(stufftodo[4]) }, /* when left front hits back left tire   */
  { SDLY(50), EDLY(0), 2500, (todolist *) &(stufftodo[4]) },  /* when right rear hits fwd right tire   */
  { SDLY(0), EDLY(50), 2500, (todolist *) &(stufftodo[4]) },  /* when left rear hits fwd left tire     */

  { SDLY(00),EDLY(45),800, (todolist *) &(stufftodo[5]) },
  { SDLY(10),EDLY(45),100, (todolist *) &(stufftodo[6]) },
  { SDLY(20),EDLY(45),100, (todolist *) &(stufftodo[7]) },
  { SDLY(30),EDLY(45),100, (todolist *) &(stufftodo[8]) },
  { SDLY(40),EDLY(45),100, (todolist *) &(stufftodo[9]) },
  { SDLY(50),EDLY(45),100, (todolist *) &(stufftodo[10]) },
  { SDLY(60),EDLY(45),100, (todolist *) &(stufftodo[11]) },
  { SDLY(70),EDLY(45),100, (todolist *) &(stufftodo[12]) },
  { SDLY(80),EDLY(45),100, (todolist *) &(stufftodo[13]) },
  { SDLY(90),EDLY(45),800, (todolist *) &(stufftodo[14]) },
  { SDLY(90),EDLY(50),100, (todolist *) &(stufftodo[15]) },
  { SDLY(90),EDLY(40),100, (todolist *) &(stufftodo[16]) },
  { SDLY(90),EDLY(45),800, (todolist *) &(stufftodo[17]) },
  { SDLY(80),EDLY(45),100, (todolist *) &(stufftodo[18]) },
  { SDLY(70),EDLY(45),100, (todolist *) &(stufftodo[19]) },
  { SDLY(60),EDLY(45),100, (todolist *) &(stufftodo[20]) },
  { SDLY(50),EDLY(45),100, (todolist *) &(stufftodo[21]) },
  { SDLY(40),EDLY(45),100, (todolist *) &(stufftodo[22]) },
  { SDLY(30),EDLY(45),100, (todolist *) &(stufftodo[23]) },
  { SDLY(20),EDLY(45),100, (todolist *) &(stufftodo[24]) },
  { SDLY(10),EDLY(45),100, (todolist *) &(stufftodo[25]) },
  { SDLY(00),EDLY(45),800, (todolist *) &(stufftodo[26]) },
  { SDLY(00),EDLY(50),100, (todolist *) &(stufftodo[27]) },
  { SDLY(00),EDLY(40),100, (todolist *) &(stufftodo[4]) }

};

#define RFSWITCHTODO  ( (todolist *) &(stufftodo[0]) )
#define LFSWITCHTODO  ( (todolist *) &(stufftodo[1]) )
#define RRSWITCHTODO  ( (todolist *) &(stufftodo[2]) )
#define LRSWITCHTODO  ( (todolist *) &(stufftodo[3]) )

static volatile todolist *thingtodo=&(stufftodo[4]);

/*;**********************Timer 1 overflow**************
 *;brings two servo lines hi, reloads servo position values
 *;
 *;_______|-|____
 *;      /\
 *;       |
 *;	overflow here
*/

SIGNAL(SIG_OVERFLOW1)
{
	sbi(SERVOPORTPINS,E_SERVO);
	sbi(SERVOPORTPINS,S_SERVO);
	outw(TCNT1,PULSESPACE);
	outw(OCR1A,eservo);
	outw(OCR1B,sservo);
}

SIGNAL(SIG_OUTPUT_COMPARE1A)
{
	cbi(SERVOPORTPINS,E_SERVO);
}

SIGNAL(SIG_OUTPUT_COMPARE1B)
{
	cbi(SERVOPORTPINS,S_SERVO);
}

SIGNAL(SIG_OVERFLOW2)
{
	outb(TCNT2,0); /*(i dunno if this is necissary )*/

        if ((--duration)<=0) {
   	  thingtodo=thingtodo->next;
        } else {
          return;
        }
	  sservo=thingtodo->shoulder+STRIM;
	  eservo=thingtodo->elbow+ETRIM;
	  duration=thingtodo->duration;

}
void main(void)
{

        outb(TIMSK,(_BV(TOIE2)|_BV(TOIE1)|_BV(OCIE1A)|_BV(OCIE1B))); /* enable TCNT overflow */
        outw(TCNT1,0xFF00); // idea is to start with an interupt (not sure if this wil work).
	outb(TCCR1A,0);
	outb(TCCR1B,2); //  ck/8

        duration=10;
	cbi(ASSR,AS2);
	outb(TCNT2,0x00);
	outb(TCCR2,3); //   ck/1024

	eservo=PULSECENTER+ETRIM;
	sservo=PULSECENTER+STRIM;

    	outb(SERVOPORTDDR,0xff);      /* servoport = output */
    	outb(SERVOPORTPINS,0x00);     /* switch outputs off */

    	sei();                 /* enable interrupts */

}