Accurate than the 3pi some twists and stop

accurate than the 3pi some twists and stop
accurate than the 3pi stop 15 seconds after the start
how to do it?
accurate than the 3pi some twists and stop
t
how to do it?

Hello.

I am not sure exactly what you are trying to do. You can get the 3pi to stop by setting both motors to “0” using the “set_motors” command. Additional “set_motors” commands can be used for forward, backward, and turn functions. You can create time based loops by comparing the difference between two “get_ms()” commands. Additionally, you can put delays in your code with the “delay(unsigned int milliseconds)” command. All of these commands can be seen in the “Pololu AVR Library Command Reference”.

If you are still unable to create the program you are attempting, I recommend posting the code you are having trouble with so we can see what might be going wrong.

-Derrill

[code]/TESTE/

#include <pololu/3pi.h>
#include <avr/pgmspace.h>
#include <pololu/orangutan.h>
#include <pololu/qtr.h>
#include <pololu/encoders.h>
#include <pololu/analog.h>
#include <pololu/buzzer.h>
#include <pololu/time.h>
#include <pololu/motors.h>
#include <pololu/lcd.h>
#include <pololu/leds.h>
#include <pololu/pushbuttons.h>
#include <pololu/serial.h>

const char welcome_line1[] PROGMEM = " Pololu";
const char welcome_line2[] PROGMEM = “3\xf7 Robot”;
const char demo_name_line1[] PROGMEM = “Line”;
const char demo_name_line2[] PROGMEM = “follower”;

const char welcome[] PROGMEM = “>g32>>c32”;
const char go[] PROGMEM = “L16 cdegreg4”;

const char levels[] PROGMEM = {
0b00000,
0b00000,
0b00000,
0b00000,
0b00000,
0b00000,
0b00000,
0b11111,
0b11111,
0b11111,
0b11111,
0b11111,
0b11111,
0b11111
};

void load_custom_characters()
{
lcd_load_custom_character(levels+0,0);
lcd_load_custom_character(levels+1,1);
lcd_load_custom_character(levels+2,2);
lcd_load_custom_character(levels+3,3);
lcd_load_custom_character(levels+4,4);
lcd_load_custom_character(levels+5,5);
lcd_load_custom_character(levels+6,6);
clear();
}

void display_readings(const unsigned int *calibrated_values)
{
unsigned char i;

for(i=0;i<5;i++) {
	
	const char display_characters[10] = {' ',0,0,1,2,3,4,5,6,255};
	
	char c = display_characters[calibrated_values[i]/101];
	
	print_character(c);
}

}

void initialize()
{
unsigned int counter;
unsigned int sensors[5];

pololu_3pi_init(2000);
load_custom_characters();

print_from_program_space(welcome_line1);
lcd_goto_xy(0,1);
print_from_program_space(welcome_line2);
play_from_program_space(welcome);
delay_ms(1000);

clear();
print_from_program_space(demo_name_line1);
lcd_goto_xy(0,1);
print_from_program_space(demo_name_line2);
delay_ms(1000);

while(!button_is_pressed(BUTTON_B))
{
	int bat = read_battery_millivolts();
	
	clear();
	print_long(bat);
	print("mV");
	lcd_goto_xy(0,1);
	print("Press B");
	
	delay_ms(100);
}

wait_for_button_release(BUTTON_B);
delay_ms(1000);

for(counter=0;counter<80;counter++)
{
if(counter < 20 || counter >= 60)
set_motors(40,-40);
else
set_motors(-40,40);

calibrate_line_sensors(IR_EMITTERS_ON);

delay_ms(20);

}
set_motors(0,0);

while(!button_is_pressed(BUTTON_B))
{
unsigned int position = read_line(sensors,IR_EMITTERS_ON);

clear();
print_long(position);
lcd_goto_xy(0,1);
display_readings(sensors);

delay_ms(100);

}
wait_for_button_release(BUTTON_B);

clear();

print(“Go!”);

play_from_program_space(go);
while(is_playing());
}

int main()
{
unsigned int sensors[5];

initialize();

while(1)
{
	unsigned int position = read_line_white(sensors,IR_EMITTERS_ON);
	
	if(position < 1000)
	{
		
		set_motors(0,100);
		
		left_led(0);
		right_led(1);
	}
	else if(position < 3000)
	{
		set_motors(100,100);
		left_led(0);
		right_led(0);
	}
	else
	{
		set_motors(100,0);
		left_led(1);
		right_led(0);
	}
}

}[/code]

it only takes one turn and stop

The video you linked to looks like it shows a 3pi Robot running a working line follower program, is the 3pi in the video the one you are having an issue with? If not, can you post a video showing the problem you are having? Can you check your batteries to be sure they are new or freshly charged and try again? If changing the batteries does not work, can you simplify your code to the simplest program that still demonstrates the problem?

-Derrill

The robot is following the line perfectly but it will I need it for a spin and stop
I want to program in a routine for him to tell time eg 15s and stop

It sounds like you want to your robot use the line follower code for about 15 seconds then stop. If so, you can use the “get_ms()” command I referenced in my first response to do something like that.

-Derrill

using the command in my program?
necessary that the robot stops after 15s I precione b button

get_ms (15000)

Hello.

You can use get_ms() to check how much time has elapsed. To stop your robot after 15 seconds , you might use something like:

// after button is pressed
unsigned long start_time = get_ms();
while(get_ms() - start_time < 15000)
{
	// insert command to move robot
}
// stop robot after it gets out of the while loop

You might also find the Arduino Blink Without Delay example helpful for understanding how get_ms() works (the millis() command for Arduino is similar to the get_ms() command).

- Jeremy

it worked thanks
one more question what is the biggest amount I can put the variable

long start_time = get_ms();
while(get_ms() - start_time < ???)

As mentioned in the “Timing and Delay” section of the AVR Library Command Reference, the maximum value that can be stored in an unsigned long is 4294967295, and that would be the largest value you could use there, which in milliseconds would correspond to a little more than 49 days. (Please note, I have changed start_time to an unsigned long in my previous code.) If you want to run it longer, you might consider using nested loops.

- Jeremy