Page 366 - Hacking Roomba

Chapter 15 — RoombaCam: Adding Eyes to Roomba 347

The roombacmd application and all other code mentioned can be downloaded from http://
roombahacking.com/software/.

Listing 15-3: roombalib.c Basics

#define COMMANDPAUSE_MILLIS 100
#define DEFAULT_VELOCITY 200
Roomba* roomba_init(char* portname)
{
int fd = roomba_init_serialport(portname,B57600);
if( fd == -1 ) return NULL;
char cmd[1];
cmd[0] = 128; // START
int n = write(fd, cmd, 1);
if( n!=1 ) {
perror(“open_port: Unable to write to port “);
return NULL;
}
roomba_delay(COMMANDPAUSE_MILLIS);
cmd[0] = 130; // CONTROL
n = write(fd, cmd, 1);
if( n!=1 ) {
perror(“open_port: Unable to write to port “);
return NULL;
}
roomba_delay(COMMANDPAUSE_MILLIS);
Roomba* roomba = calloc(1, sizeof(Roomba));
roomba->fd = fd;
roomba->velocity = DEFAULT_VELOCITY;
return roomba;
}
void roomba_drive(Roomba* roomba, int velocity, int radius)
{
char vhi = velocity >> 8;
char vlo = velocity & 0xff;
char rhi = radius >> 8;
char rlo = radius & 0xff;
if(roombadebug) fprintf(stderr,
“roomba_drive: %.2hhx %.2hhx %.2hhx
%.2hhx\n”,