Diff: main.cpp

Revision:

0:6895e81fba91

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Jun 30 06:28:12 2017 +0000
@@ -0,0 +1,56 @@
+/* See
+ * http://lancaster-university.github.io/microbit-docs/advanced/
+ * for docs about using the micro:bit library
+*/
+#ifndef M_PI
+#define M_PI           3.14159265358979323846
+#endif
+
+#include "MicroBit.h"
+
+// a,b line normal vector coordinates, should be normalized, a^2 + b^2 = 1 
+// returns if distance of point at coordinates x, y and vector line does not 
+// exceed given range
+bool inRange(float a, float b, float x, float y, float range = 0.5)
+{
+    return abs(a*x + b*y) < range;
+}
+// answer if the LED in row, column should be lit or turned off
+bool isLit(float a, float b, int row, int column)
+{
+    float x = column - 2;
+    float y = 2 - row;
+    return inRange(a,b,x,y);
+}
+
+float deg2rad(int deg)
+{
+    return (float) deg * M_PI / 180;
+}
+
+MicroBit uBit;
+
+int main()
+{
+
+
+    uBit.init();
+
+    while (true) {
+        int heading = uBit.compass.heading();
+        //uBit.serial.printf("%d\r\n", heading);
+        
+        float angle = M_PI / 2 - deg2rad(heading); //calculate angle of displayed line
+        float a = sin(angle); //calculate line normal vector parameters a, b
+        float b = cos(angle); 
+        
+        for (int row = 0; row < 5; row++) {
+            for (int col = 0; col < 5; col++) {
+                uBit.display.image.setPixelValue(col,row,isLit(a, b, row, col) ? 255 : 0);
+            }
+        }
+        
+        uBit.sleep (100);
+    }
+}
+