Pololu 3pi Robot User Manual

Page 55

set_motors(-60, 60);

while(get_ms() < 750)

calibrate_line_sensors(IR_EMITTERS_ON);

set_motors(60, -60);

while(get_ms() < 1000)

calibrate_line_sensors(IR_EMITTERS_ON);

set_motors(0, 0);

serial_send_blocking("c",1);

}

// Turns on PID according to the supplied PID constants

void set_pid()

{

unsigned char constants[5];

unsigned char i;

for(i=0;i<5;i++)

{

constants[i] = read_next_byte();

if(check_data_byte(constants[i]))

return;

}

// make the max speed 2x of the first one, so that it can reach 255

max_speed = (constants[0] == 127 ? 255 : constants[0]*2);

// set the other parameters directly

p_num = constants[1];

p_den = constants[2];

d_num = constants[3];

d_den = constants[4];

// enable pid

pid_enabled = 1;

}

// Turns off PID

void stop_pid()

{

set_motors(0,0);

pid_enabled = 0;

}

/////////////////////////////////////////////////////////////////////

int main()

{

pololu_3pi_init(2000);

play_mode(PLAY_CHECK);

clear();

print("Slave");

// start receiving data at 115.2 kbaud

serial_set_baud_rate(115200);

serial_set_mode(SERIAL_CHECK);

serial_receive_ring(buffer, 100);

while(1)

{

// wait for a command

char command = read_next_byte();

// The list of commands is below: add your own simply by

// choosing a command byte and introducing another case

// statement.

switch(command)

{

case (char)0x00:

// slient error - probable master resetting

break;

case (char)0x81:

send_signature();

break;

case (char)0x86:

send_raw_sensor_values();

Pololu 3pi Robot User's Guide

10. Expansion Information

Page 55 of 63