From 8cd677d697144898cb554f7744dea4e64723968e Mon Sep 17 00:00:00 2001
From: Damjan Adamic <projectkk2glider@gmail.com>
Date: Fri, 6 May 2016 22:35:17 +0200
Subject: [PATCH] Projectkk2glider/issue 3463 negative filtered sensor values
 (#3469) (ported from master)

* Fixes #3463: negative sensor values were invalid if filter was active for the sensor

* Re #3463: enable simultaneous use of `offset` and `filter` (was: when `offset` was enabled, the `filter` was always inactive even if enabled)
---
 radio/src/telemetry/telemetry_sensors.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/radio/src/telemetry/telemetry_sensors.cpp b/radio/src/telemetry/telemetry_sensors.cpp
index 74bef8907..63ac6f7b7 100644
--- a/radio/src/telemetry/telemetry_sensors.cpp
+++ b/radio/src/telemetry/telemetry_sensors.cpp
@@ -171,16 +171,18 @@ void TelemetryItem::setValue(const TelemetrySensor & sensor, int32_t val, uint32
       }
       newVal += std.offsetAuto;
     }
-    else if (sensor.filter) {
+    if (sensor.filter) {
       if (!isAvailable()) {
         for (int i=0; i<TELEMETRY_AVERAGE_COUNT; i++) {
           std.filterValues[i] = newVal;
         }
       }
       else {
-        // calculate the average from values[] and value
-        // also shift readings in values [] array
-        unsigned int sum = std.filterValues[0];
+        // Calculate the average from values[] and value,
+        // also shift readings in values [] array.
+        // There is a possibility of value overflow in `sum` but
+        // in reality no sensor value should be so big to cause it.
+        int32_t sum = std.filterValues[0];
         for (int i=0; i<TELEMETRY_AVERAGE_COUNT-1; i++) {
           int32_t tmp = std.filterValues[i+1];
           std.filterValues[i] = tmp;