Source code – Pololu 3pi Robot User Manual

Page 57

• GND-GND

• PD0-PD1

• PD1-PD0

Turn on both master and slave. The master will display a “Connect” message followed by the signature of the slave
source code (e.g. “3pi1.0”). The master will then instruct the slave to display “Connect” and play a short tune.
Pressing the B botton on the master causes the slave to go through an auto-calibration routine, after which you can
drive the slave around using the A and C buttons on the master, while viewing sensor data on the master’s LCD.
Holding down the B button causes the slave to do PID line following.

Source code

#include

* 3pi-serial-master - An example serial master program for the Pololu

* 3pi Robot. This can run on any board supported by the library;

* it is intended as an example of how to use the master/slave

* routines.

* http://www.pololu.com/docs/0J21

* http://www.pololu.com/docs/0J20

* http://www.poolu.com/

// Data for generating the characters used in load_custom_characters

// and display_readings. By reading levels[] starting at various

// offsets, we can generate all of the 7 extra characters needed for a

// bargraph. This is also stored in program space.

const char levels[] PROGMEM = {

0b00000,

0b11111,

0b11111

};

// This function loads custom characters into the LCD. Up to 8

// characters can be loaded; we use them for 6 levels of a bar graph

// plus a back arrow and a musical note character.

void load_custom_characters()

{

lcd_load_custom_character(levels+0,0); // no offset, e.g. one bar

lcd_load_custom_character(levels+1,1); // two bars

lcd_load_custom_character(levels+2,2); // etc...

lcd_load_custom_character(levels+4,3); // skip level 3

lcd_load_custom_character(levels+5,4);

lcd_load_custom_character(levels+6,5);

clear(); // the LCD must be cleared for the characters to take effect

}

// 10 levels of bar graph characters

const char bar_graph_characters[10] = {' ',0,0,1,2,3,3,4,5,255};

void display_levels(unsigned int *sensors)

{

clear();

int i;

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

// Initialize the array of characters that we will use for the

// graph. Using the space, an extra copy of the one-bar

Pololu 3pi Robot User's Guide

10. Expansion Information

Page 57 of 63