Example DesignProgramming controls for an imaginary robot.

The robot has to drive around, use a camera to track a green light, aim using a turret, and shoot projectiles at the target.

The drive system for the robot consists of two independent drive channels, controlled by two separate PWMs driven by two joysticks. The joysticks’ y-axes control the velocities of the drive motors; stopped, forward and reverse.

The turret autonomously tracks the target using the CMU Cam2 and is limited in its travel to +/- 45 degrees by a potentiometer.

The driver can re-center the turret with a button on the joystick, and can drive the shooter to load and fire with another button.

The OI is programmed to have indicators for the drive controls and a “locked-on-target” LED.

void main (void){#ifdef UNCHANGEABLE_DEFINITION_AREA IFI_Initialization (); /* DO NOT CHANGE! */#endif

User_Initialization(); /* You edit this in user_routines.c */

statusflag.NEW_SPI_DATA = 0; /* DO NOT CHANGE! */

while (1) /* This loop will repeat indefinitely. */ {#ifdef _SIMULATOR statusflag.NEW_SPI_DATA = 1;#endif

if (statusflag.NEW_SPI_DATA) /* 26.2ms loop area */ { /* I'm slow! I only execute every 26.2ms because */ /* that's how fast the Master uP gives me data. */ Process_Data_From_Master_uP(); /* You edit this in user_routines.c */

if (autonomous_mode) /* DO NOT CHANGE! */ { User_Autonomous_Code(); /* You edit this in user_routines_fast.c */ } } Process_Data_From_Local_IO(); /* You edit this in user_routines_fast.c */ /* I'm fast! I execute during every loop.*/ } /* while (1) */} /* END of Main */

void Process_Data_From_Master_uP(void){ static unsigned char i;

Getdata(&rxdata); /* Get fresh data from the master microprocessor. */

Camera_Process_Data_From_Master_uP();

Default_Routine(); /* Optional. See below. */

/* Add your own code here. (a printf will not be displayed when connected to the breaker panel unless a Y cable is used) */

printf("Port1 Y %3d, X %3d, Fire %d, Top %d\r",pwm01,pwm05,p1_sw_trig,p1_sw_top); /* printf EXAMPLE */

Generate_Pwms(pwm13,pwm14,pwm15,pwm16);

Putdata(&txdata); /* DO NOT CHANGE! */}

void Default_Routine(void) {

//pwm01 left drive motors

//pwm02 right drive motors

//pwm03 firing motor

//pwm04 shooter loader motor

//relay1 turret rotator motor

DriveControl();

TurretControl();

ShooterControl();

IndicatorOutput();

} /* END Default_Routine(); */

void DriveControl(void) {/* Using pwm01 as left drive motors and pwm02 as right * drive motors. We are limiting the change of the speed of * the drive motors to be less than +/-32.*/int delta = 32; //Allowable change to drive pwms per 26.2ms(tick)pwm01 = DeltaLimiter(delta, pwm01, p1_y);pwm02 = DeltaLimiter(delta, pwm02, p2_y);

}

int DeltaLimiter(int delta, int pwm, int joy) {if (joy > (pwm + delta)) {

return (pwm + delta);} else {

if (joy < (pwm - delta)) {return (pwm - delta);

} else {return joy;

}}

}

void TurretControl(void) {int pot = Get_Analog_Value(turret_pot);int lowerBuffer = 10;if (p3_sw_top) { //recalibrate button

if (pot < 124) {relay1_fwd = 1;relay1_rev = 0;

} else {if (pot > 130) {

relay1_fwd = 0;relay1_rev = 1;

} else {relay1_fwd = 0;relay1_rev = 0;

}}

} else {if (Get_Tracking_State() & STATE_PAN_ON_TARGET) { // Camera locked

int min = 64;int max = 192;if (PAN_SERVO > (127 + lowerBuffer)) {

relay1_fwd = DegreeLimiter(min, max, turret_pot);relay1_rev = 0;

} else {if (PAN_SERVO < (127 - lowerBuffer)) {

relay1_rev = DegreeLimiter(min, max, turret_pot);

relay1_fwd = 0;} else {

relay1_fwd = 0;relay1_rev = 0;

}}

} else {relay1_fwd = 0;relay1_rev = 0;

}}

}

int DeltaLimiter(int delta, int pwm, int joy) {if (joy > (pwm + delta)) {

return (pwm + delta);} else {

if (joy < (pwm - delta)) {return (pwm - delta);

} else {return joy;

}}

}

void ShooterControl(void) {

if (p4_sw_trig) {

pwm03 = 255;

pwm04 = 255;

} else {

pwm03 = 127;

pwm04 = 127;

}

}

void IndicatorOutput(void) {

//…Code Hidden

Switch1_LED = !(int)rc_dig_in01;

Switch2_LED = !(int)rc_dig_in02;

if (Get_Tracking_State() & STATE_PAN_ON_TARGET ) {

Switch3_LED = 1;

} else {

Switch3_LED = 0;

}

}