From 1a6076c253bee6ba882b0e3e78e92a5b61af5484 Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Tue, 14 Mar 2023 09:28:00 +0100
Subject: [PATCH] Add flush before disabling tx (#17247)

---
 lib/default/TasmotaSerial-3.6.0/src/TasmotaSerial.cpp   | 1 +
 lib/lib_basic/TasmotaModbus-3.6.0/src/TasmotaModbus.cpp | 1 +
 2 files changed, 2 insertions(+)

diff --git a/lib/default/TasmotaSerial-3.6.0/src/TasmotaSerial.cpp b/lib/default/TasmotaSerial-3.6.0/src/TasmotaSerial.cpp
index a233422be..e54692ab5 100644
--- a/lib/default/TasmotaSerial-3.6.0/src/TasmotaSerial.cpp
+++ b/lib/default/TasmotaSerial-3.6.0/src/TasmotaSerial.cpp
@@ -460,6 +460,7 @@ size_t TasmotaSerial::write(uint8_t b) {
     size = 1;
   }
   if (m_tx_enable_pin > -1) {
+    flush();  // Must wait for all data sent
     digitalWrite(m_tx_enable_pin, LOW);
   }
   return size;
diff --git a/lib/lib_basic/TasmotaModbus-3.6.0/src/TasmotaModbus.cpp b/lib/lib_basic/TasmotaModbus-3.6.0/src/TasmotaModbus.cpp
index 4319c5d8a..0ab48f824 100644
--- a/lib/lib_basic/TasmotaModbus-3.6.0/src/TasmotaModbus.cpp
+++ b/lib/lib_basic/TasmotaModbus-3.6.0/src/TasmotaModbus.cpp
@@ -171,6 +171,7 @@ uint8_t TasmotaModbus::Send(uint8_t device_address, uint8_t function_code, uint1
   write(frame, framepointer);
 #ifdef TASMOTA_MODBUS_TX_ENABLE
   if (mb_tx_enable_pin > -1) {
+    flush();  // Must wait for all data sent
     digitalWrite(mb_tx_enable_pin, LOW);
   }
 #endif  // TASMOTA_MODBUS_TX_ENABLE