From ed3bf2c1e7e02d12e2f58f21bab79cf2baddd093 Mon Sep 17 00:00:00 2001
From: Randy Mackay <rmackay9@yahoo.com>
Date: Sun, 7 Jul 2013 17:49:45 -1000
Subject: [PATCH] Copter: relax pre-arm checks for mag field

previously it was 50% ~ 150% of expected mag field but now expanded to
35% ~ 165%.
---
 ArduCopter/motors.pde | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ArduCopter/motors.pde b/ArduCopter/motors.pde
index 07aab627fa..c73860ee08 100644
--- a/ArduCopter/motors.pde
+++ b/ArduCopter/motors.pde
@@ -249,7 +249,7 @@ static void pre_arm_checks(bool display_failure)
 
     // check for unreasonable mag field length
     float mag_field = pythagorous3(compass.mag_x, compass.mag_y, compass.mag_z);
-    if (mag_field > COMPASS_MAGFIELD_EXPECTED*1.5 || mag_field < COMPASS_MAGFIELD_EXPECTED*0.5) {
+    if (mag_field > COMPASS_MAGFIELD_EXPECTED*1.65 || mag_field < COMPASS_MAGFIELD_EXPECTED*0.35) {
         if (display_failure) {
             gcs_send_text_P(SEVERITY_HIGH,PSTR("PreArm: Check mag field"));
         }