Jan Koupil
A simple compass using the BBC Micro:Bit. Uses a point-line distance calculation to light the LEDs instead of commonly used pre-calculated LED Matrix which gives nicer representation of the direction.
Revision 0:6895e81fba91, committed 2017-06-30
- Comitter:
- jan_koupil
- Date:
- Fri Jun 30 06:28:12 2017 +0000
- Commit message:
- Initial commit
Changed in this revision
| main.cpp | Show annotated file Show diff for this revision Revisions of this file |
| microbit.lib | Show annotated file Show diff for this revision Revisions of this file |
--- /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);
+ }
+}
+
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/microbit.lib Fri Jun 30 06:28:12 2017 +0000 @@ -0,0 +1,1 @@ +https://developer.mbed.org/teams/Lancaster-University/code/microbit/#4b89e7e3494f