From 5588229f681494df8b60c57c613c8288e9fc77d0 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 9 Jan 2020 07:08:11 +1100
Subject: [PATCH] AP_RCProtocol: fixed scaling on FPort RSSI

make it match OpenTX
---
 libraries/AP_RCProtocol/AP_RCProtocol_FPort.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libraries/AP_RCProtocol/AP_RCProtocol_FPort.cpp b/libraries/AP_RCProtocol/AP_RCProtocol_FPort.cpp
index 2550b3246f..612171d2cf 100644
--- a/libraries/AP_RCProtocol/AP_RCProtocol_FPort.cpp
+++ b/libraries/AP_RCProtocol/AP_RCProtocol_FPort.cpp
@@ -22,6 +22,7 @@
 #include <AP_Frsky_Telem/AP_Frsky_Telem.h>
 #include <AP_Vehicle/AP_Vehicle_Type.h>
 #include <RC_Channel/RC_Channel.h>
+#include <AP_Math/AP_Math.h>
 
 extern const AP_HAL::HAL& hal;
 
@@ -116,7 +117,11 @@ void AP_RCProtocol_FPort::decode_control(const FPort_Frame &frame)
     }
 
     bool failsafe = ((frame.control.flags & (1 << FLAGS_FAILSAFE_BIT)) != 0);
-    add_input(MAX_CHANNELS, values, failsafe, frame.control.rssi);
+
+    // we scale rssi by 2x to make it match the value displayed in OpenTX
+    const uint8_t scaled_rssi = MIN(frame.control.rssi*2, 255);
+
+    add_input(MAX_CHANNELS, values, failsafe, scaled_rssi);
 }
 
 /*