Diff: LocationHandler.h

Revision:

0:4eaf38ccb19c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LocationHandler.h	Fri Aug 24 03:21:43 2012 +0000
@@ -0,0 +1,79 @@
+#include <math.h>
+#include <string.h>
+
+#define NOTFOUND_MARK (-65536)
+
+struct apinfo registered_ap[] = {
+    { "ap-game-432afd", {0, 0x22, 0xcf, 0x43, 0x2a, 0xfd}, 0 },
+    { "ap-pc-432afc", {0, 0x22, 0xcf, 0x43, 0x2a, 0xfc}, 0 },
+    { "ap-game-433f85", {0, 0x22, 0xcf, 0x43, 0x3f, 0x85}, 0 },
+    { "ap-pc-433f84", {0, 0x22, 0xcf, 0x43, 0x3f, 0x84}, 0 },
+    { "ap-game-433223", {0, 0x22, 0xcf, 0x43, 0x32, 0x23}, 0 },
+    { "ap-pc-433222", {0, 0x22, 0xcf, 0x43, 0x32, 0x22}, 0 },
+    { "ap-game-4334c9", {0, 0x22, 0xcf, 0x43, 0x34, 0xc9}, 0 },
+    { "ap-pc-4334c8", {0, 0x22, 0xcf, 0x43, 0x34, 0xc8}, 0 }
+};  // this structure must be writable
+
+struct pos {
+    float x, y;
+};
+
+const struct pos registered_pos[] = {
+    {0.0, 0.0}, {0.0, 0.0}, {0.0, 100.0}, {0.0, 100.0}, 
+    {100.0, 0.0}, {100.0, 0.0}, {100.0, 100.0}, {100.0, 100.0}
+};
+
+struct pos result_pos;
+
+void LocationManagerCalcPos(int apinfo_count, struct apinfo* searched_ap)
+{
+    int i, j, k;
+    int match_count;
+    const int length_of_registered_ap = sizeof(registered_ap) / sizeof(struct apinfo);
+    float proportion;
+    float sum;
+
+    for ( i = 0; i < length_of_registered_ap; i++ ) {
+        registered_ap[i].power = NOTFOUND_MARK;
+    }
+    match_count = 0;
+    for ( i = 0; i < apinfo_count; i++ ) {
+        for ( j = 0; j < length_of_registered_ap; j++ ) {
+            for ( k = 0; k < ESSID_LEN; k++ ) {
+                if ( registered_ap[j].essid[k] == '\0' ) {
+                    break;
+                }
+                if ( searched_ap[i].essid[k] != registered_ap[j].essid[k] ) {
+                    goto no_match;
+                }
+            }
+            if ( memcmp( registered_ap[j].bssid, searched_ap[i].bssid, MACADDR_LEN) != 0 ) {
+                continue;
+            }
+            registered_ap[j].power = searched_ap[i].power;
+            match_count++;
+            break;
+no_match:;
+        }
+    }
+    
+    if ( match_count == 0 ) {
+        lcd.cls();
+        lcd.printf("location lost\nAP count %d", apinfo_count);
+        return;
+    }
+    
+    result_pos.x = result_pos.y = 0.0;
+    sum = 0.0;
+    for ( i = 0; i < length_of_registered_ap; i++ ) {
+        proportion = pow(10, registered_ap[i].power / 40.0f);   // calc dB to linear number
+        sum += proportion;
+        result_pos.x += registered_pos[i].x * proportion;
+        result_pos.y += registered_pos[i].y * proportion;
+    }
+    result_pos.x /= sum;
+    result_pos.y /= sum;
+    
+    lcd.cls();
+    lcd.printf("AP %d/%d, location x=%.1f, y=%.1f", match_count, apinfo_count, result_pos.x, result_pos.y);
+}
\ No newline at end of file