From ed20c4cbc82e152c1068b6adf14502e3e3ac9ecc Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Sun, 14 Jul 2013 21:59:15 +1000
Subject: [PATCH] Plane: fixed initial reporting of battery remaining

we were not showing battery remaining 100% until we used some battery
---
 ArduPlane/ArduPlane.pde   |  2 ++
 ArduPlane/GCS_Mavlink.pde |  8 ++++----
 ArduPlane/sensors.pde     | 13 ++++++-------
 3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/ArduPlane/ArduPlane.pde b/ArduPlane/ArduPlane.pde
index c3a47763e9..e808f51bb3 100644
--- a/ArduPlane/ArduPlane.pde
+++ b/ArduPlane/ArduPlane.pde
@@ -447,6 +447,8 @@ static struct {
     float current_total_mah;
     // true when a low battery event has happened
     bool low_batttery;
+    // time when current was last read
+    uint32_t last_time_ms;
 } battery;
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/ArduPlane/GCS_Mavlink.pde b/ArduPlane/GCS_Mavlink.pde
index 02d25683ae..131a2d3f45 100644
--- a/ArduPlane/GCS_Mavlink.pde
+++ b/ArduPlane/GCS_Mavlink.pde
@@ -216,10 +216,10 @@ static NOINLINE void send_extended_status1(mavlink_channel_t chan, uint16_t pack
     uint16_t battery_current = -1;
     uint8_t battery_remaining = -1;
 
-    if (battery.current_total_mah != 0 && g.pack_capacity != 0) {
-        battery_remaining = (100.0 * (g.pack_capacity - battery.current_total_mah) / g.pack_capacity);
-    }
-    if (battery.current_total_mah != 0) {
+    if (battery.last_time_ms != 0) {
+        if (g.pack_capacity != 0) {
+            battery_remaining = (100.0 * (g.pack_capacity - battery.current_total_mah) / g.pack_capacity);
+        }
         battery_current = battery.current_amps * 100;
     }
 
diff --git a/ArduPlane/sensors.pde b/ArduPlane/sensors.pde
index eb9a112c05..ddac273e83 100644
--- a/ArduPlane/sensors.pde
+++ b/ArduPlane/sensors.pde
@@ -52,17 +52,16 @@ static void read_battery(void)
     }
 
     if (g.battery_monitoring == 4) {
-        static uint32_t last_time_ms;
         uint32_t tnow = hal.scheduler->millis();
-        float dt = tnow - last_time_ms;
-        if (last_time_ms != 0 && dt < 2000) {
-            // this copes with changing the pin at runtime
-            batt_curr_pin->set_pin(g.battery_curr_pin);
-            battery.current_amps    = CURRENT_AMPS(batt_curr_pin);
+        float dt = tnow - battery.last_time_ms;
+        // this copes with changing the pin at runtime
+        batt_curr_pin->set_pin(g.battery_curr_pin);
+        battery.current_amps = CURRENT_AMPS(batt_curr_pin);
+        if (battery.last_time_ms != 0 && dt < 2000) {
             // .0002778 is 1/3600 (conversion to hours)
             battery.current_total_mah += battery.current_amps * dt * 0.0002778f; 
         }
-        last_time_ms = tnow;
+        battery.last_time_ms = tnow;
     }
 
     if (battery.voltage != 0 &&