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print_long(bat);
print(
"mV"
);
lcd_goto_xy(0,1);
print(
"Press B"
);
delay_ms(100);
}
// Always wait for the button to be released so that 3pi doesn't
// start moving until your hand is away from it.
wait_for_button_release(BUTTON_B);
delay_ms(1000);
// Auto-calibration: turn right and left while calibrating the
// sensors.
for
(counter=0;counter<80;+)
{
if
(counter < 20 || counter >= 60)
set_motors(40,-40);
else
set_motors(-40,40);
// This function records a set of sensor readings and keeps
// track of the minimum and maximum values encountered.
The
// IR_EMITTERS_ON argument means that the IR LEDs will be
// turned on during the reading, which is usually what you
// want.
calibrate_line_sensors(IR_EMITTERS_ON);
// Since our counter runs to 80, the total delay will be
// 80*20 = 1600 ms.
delay_ms(20);
}
set_motors(0,0);
// Display calibrated values as a bar graph.
while
(!button_is_pressed(BUTTON_B))
{
// Read the sensor values and get the position measurement.
unsigned
int
position = read_line(sensors,IR_EMITTERS_ON);
// Display the position measurement, which will go from 0
// (when the leftmost sensor is over the line) to 4000 (when
// the rightmost sensor is over the line) on the 3pi, along
// with a bar graph of the sensor readings.
This allows you
// to make sure the robot is ready to go.
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 music and wait for it to finish before we start driving.
play_from_program_space(go);
while
(is_playing());
Pololu 3pi Robot User’s Guide
© 2001–2019 Pololu Corporation
7. Example Project #1: Line Following
Page 33 of 85
