New example

README.md

@@ -28,7 +28,7 @@ Ctrl-C
 - Synchronizing motors
 - Obstacle avoidance
 
-**Example files** : `sensor.c motor.c synch.c avoid.c` 
+**Example files** : `sensor.c motor.c motor_synch.c avoid.c avoid_alter.c` 
 
 ## Working Principles
 ### DC Motor Driver

src/examples/Makefile

@@ -3,7 +3,7 @@ CFLAGS = -I. -Wall
 LDFLAGS = -L.
 LDLIBS = -lrobot
 LIBS = -lwiringPi
-EXE = sensor motor synch avoid
+EXE = sensor motor motor_synch avoid avoid_alter
 
 all : $(EXE)
 

src/examples/avoid_alter.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <wiringPi.h>
+#include "robot.h"
+
+/* Macros */
+#define MINDIST		10	// possible range 2~400 cm (3.3V)
+#define SPEEDA		150 	// possible range 60~255 PWM
+#define SPEEDB		150
+
+int turning = 0;
+char turn_dir;
+
+int main(void)
+{
+	setup();
+	float dist;
+	while (1) {
+		dist = calc_dist();
+		delay(10);
+
+		/* Modify here */
+		if ((dist < MINDIST) && (dist > 0)) {
+			if(prev_dir == FW){
+				if (turning) {
+					turning = 0;
+					turn_dir = LEFT;
+				}
+				else {
+					turning = 1;
+					turn_dir = RIGHT;
+				}
+			}
+			move_slow(turn_dir, SPEEDA, SPEEDB);
+		}
+		else {
+			move_slow(FW, SPEEDA, SPEEDB);
+		}
+	}
+
+	return 0;
+}