From 9638f6cab9c51928c98488150de5266540a5245b Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 14 Jun 2018 09:10:14 +1000
Subject: [PATCH] AP_BattMonitor: changes from PR review

---
 .../AP_BattMonitor_BLHeliESC.cpp              | 26 +++++++++++++------
 .../AP_BattMonitor/AP_BattMonitor_BLHeliESC.h |  5 +++-
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.cpp b/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.cpp
index b946258fda..c8fb24a6f6 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.cpp
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.cpp
@@ -29,7 +29,7 @@ void AP_BattMonitor_BLHeliESC::init(void)
 
 void AP_BattMonitor_BLHeliESC::read(void)
 {
-    AP_BLHeli *blheli = AP_BLHeli::get_instance();
+    AP_BLHeli *blheli = AP_BLHeli::get_singleton();
     if (!blheli) {
         return;
     }
@@ -42,21 +42,25 @@ void AP_BattMonitor_BLHeliESC::read(void)
     uint32_t now = AP_HAL::millis();
     uint32_t highest_ms=0;
     
-    for (uint8_t i=0; i<8; i++) {
+    for (uint8_t i=0; i<AP_BLHELI_MAX_ESCS; i++) {
         AP_BLHeli::telem_data td;
-        uint32_t timestamp_ms;
-        blheli->get_telem_data(i, td, timestamp_ms);
-        if (now - timestamp_ms > 1000) {
+        blheli->get_telem_data(i, td);
+
+        // accumulate consumed_sum regardless of age, to cope with ESC
+        // dropping out
+        consumed_sum += td.consumption;
+        
+        if (now - td.timestamp_ms > 1000) {
             // don't use old data
             continue;
         }
+        
         num_escs++;
         voltage_sum += td.voltage;
         current_sum += td.current;
-        consumed_sum += td.consumption;
         temperature_sum += td.temperature;
-        if (timestamp_ms > highest_ms) {
-            highest_ms = timestamp_ms;
+        if (td.timestamp_ms > highest_ms) {
+            highest_ms = td.timestamp_ms;
         }
     }
 
@@ -73,6 +77,12 @@ void AP_BattMonitor_BLHeliESC::read(void)
     _state.consumed_mah = consumed_sum;
     _state.last_time_micros = highest_ms * 1000;
     _state.temperature_time = highest_ms;
+
+    if (current_sum > 0) {
+        // if we have ever got a current value then we know we have a
+        // current sensor
+        have_current = true;
+    }
 }
 
 #endif // HAVE_AP_BLHELI_SUPPORT
diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.h b/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.h
index 486864b1c5..ebe55f7d24 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.h
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_BLHeliESC.h
@@ -35,5 +35,8 @@ public:
     void read() override;
 
     // BLHeliESC provides current info
-    bool has_current() const override { return true; };
+    bool has_current() const override { return have_current; };
+
+private:
+    bool have_current;
 };