From b4a9684a7438e0dd1a425703982b5a65156a3072 Mon Sep 17 00:00:00 2001
From: mishafarms <github@mishafarms.us>
Date: Mon, 20 Jan 2020 12:34:57 -0800
Subject: [PATCH] Fix SerialBT.flush (#3579)

* Fix flush

flush should not flush the read buffer, it should wait till all output is drained from the write buffer.

* Update BluetoothSerial.cpp

Co-authored-by: Me No Dev <me-no-dev@users.noreply.github.com>
---
 libraries/BluetoothSerial/src/BluetoothSerial.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libraries/BluetoothSerial/src/BluetoothSerial.cpp b/libraries/BluetoothSerial/src/BluetoothSerial.cpp
index 5b554f0d..a52e48d8 100755
--- a/libraries/BluetoothSerial/src/BluetoothSerial.cpp
+++ b/libraries/BluetoothSerial/src/BluetoothSerial.cpp
@@ -660,7 +660,11 @@ size_t BluetoothSerial::write(const uint8_t *buffer, size_t size)
 
 void BluetoothSerial::flush()
 {
-    while(read() >= 0){}
+    if (_spp_tx_queue != NULL){
+        while(uxQueueMessagesWaiting(_spp_tx_queue) > 0){
+	    delay(5);
+        }
+    }
 }
 
 void BluetoothSerial::end()