Society of Robots - Robot Forum

Software => Software => Topic started by: lcab on March 23, 2010, 07:21:29 PM

Title: need help doing a subroutine on a axon atmega 640
Post by: lcab on March 23, 2010, 07:21:29 PM

i am trying to write a subroutine for a line follower sensor called tracker 3.0 made by lynx motion. my problems is that i cant get it to go in a straight line if it goes to one side a little bit more then the other. i added a delay to avoid the blind spot but i can't make it go in straight line
this is the code so far
#include "sys/axon.h"
#include "a2d.h"
#include "servos.h"

// Define two motors

SERVO m2a = MAKE_SERVO(FALSE, E5,1499,453); //left side
SERVO m1a = MAKE_SERVO(TRUE, E4,1500,503);  //right side
SERVO arm = MAKE_SERVO(TRUE, H4,1500,500); //gripper arm
// Create the list - remember to place an & at the start of each servo name
SERVO_LIST servos[] = {&m1a,&m2a,&arm};

// Create a driver for the list of servos

SERVO_DRIVER bank1 = MAKE_SERVO_DRIVER(servos);


// Global variable that indicates the current state

uint8_t state;





// Initialise the servos

void appInitHardware(void){
    servoPWMInit(&bank1);
    }
TICK_COUNT appInitSoftware(TICK_COUNT loopStart){
    return 0;
    }
TICK_COUNT appControl(LOOP_COUNT loopCount, TICK_COUNT loopStart){

// A3 Left
// A4

Title: Re: need help doing a subroutine on a axon atmega 640
Post by: Admin on March 24, 2010, 09:53:48 PM

The LynxMotion Tracker has only 3 sensors on it, meaning the resolution is very poor. Poor resolution leads to robot oscillation, in other words, your robot will have trouble going straight.

Two solutions . . . get more sensors, or . . .

Program your robot to go straight more than it turns.

For example, in pseudocode . . .

if(line is on left)
  left_wheel=slow
  right_wheel=fast
if(line is on right)
  left_wheel=fast
  right_wheel=slow
else(line is in center)
  left_wheel=right_wheel=fast

Your robot will always go forward, because all wheels are going forward always, but your bot will turn just a little when the line goes off center.