From 9fb326c92bdbe45d2ab7076dc67e24e111fefac0 Mon Sep 17 00:00:00 2001
From: Jonas Scharpf <jonas@brainelectronics.de>
Date: Wed, 19 Jul 2023 22:47:47 +0200
Subject: [PATCH] Add single char wait time after flush to avoid RTU control
 pin timing issue, see #68 and #72

---
 changelog.md       | 7 ++++++-
 package.json       | 2 +-
 umodbus/serial.py  | 2 ++
 umodbus/version.py | 2 +-
 4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/changelog.md b/changelog.md
index e64a3ce..6377292 100644
--- a/changelog.md
+++ b/changelog.md
@@ -15,6 +15,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 <!-- ## [Unreleased] -->
 
 ## Released
+## [2.3.7] - 2023-07-19
+### Fixed
+- Add a single character wait time after flush to avoid timing issues with RTU control pin, see #68 and #72
+
 ## [2.3.6] - 2023-07-19
 ### Added
 - Add contribution guideline, see #67
@@ -303,8 +307,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - PEP8 style issues on all files of [`lib/uModbus`](lib/uModbus)
 
 <!-- Links -->
-[Unreleased]: https://github.com/brainelectronics/micropython-modbus/compare/2.3.6...develop
+[Unreleased]: https://github.com/brainelectronics/micropython-modbus/compare/2.3.7...develop
 
+[2.3.7]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.7
 [2.3.6]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.6
 [2.3.5]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.5
 [2.3.4]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.4
diff --git a/package.json b/package.json
index ffac8a7..a34361d 100644
--- a/package.json
+++ b/package.json
@@ -38,5 +38,5 @@
         ]
     ],
     "deps": [],
-    "version": "2.3.6"
+    "version": "2.3.7"
 }
\ No newline at end of file
diff --git a/umodbus/serial.py b/umodbus/serial.py
index 5f60896..11b8bee 100644
--- a/umodbus/serial.py
+++ b/umodbus/serial.py
@@ -274,8 +274,10 @@ def _send(self, modbus_pdu: bytes, slave_addr: int) -> None:
         # 360-400us @ 9600-115200 baud (measured) (ESP32 @ 160/240MHz)
         self._uart.write(modbus_adu)
         send_finish_time = time.ticks_us()
+
         if self._has_uart_flush:
             self._uart.flush()
+            time.sleep_us(self._t1char)
         else:
             sleep_time_us = (
                 self._t1char * len(modbus_adu) -    # total frame time in us
diff --git a/umodbus/version.py b/umodbus/version.py
index 1b69b57..e6b8ffa 100644
--- a/umodbus/version.py
+++ b/umodbus/version.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
 # -*- coding: UTF-8 -*-
 
-__version_info__ = ("2", "3", "6")
+__version_info__ = ("2", "3", "7")
 __version__ = '.'.join(__version_info__)