From 7dbdddb5953bc85174f86ef3e27716f58a26e170 Mon Sep 17 00:00:00 2001
From: proddy <paul@derbyshire.nl>
Date: Sun, 30 Aug 2020 21:18:40 +0200
Subject: [PATCH] merge with Michael's latest uart code -
 https://github.com/proddy/EMS-ESP/commit/754356b5e280d00e7be0990a6026e0f782de48dc

---
 src/uart/emsuart_esp8266.cpp | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/uart/emsuart_esp8266.cpp b/src/uart/emsuart_esp8266.cpp
index 720a199bd..8c278eb6c 100644
--- a/src/uart/emsuart_esp8266.cpp
+++ b/src/uart/emsuart_esp8266.cpp
@@ -46,9 +46,9 @@ void ICACHE_RAM_ATTR EMSuart::emsuart_rx_intr_handler(void * para) {
 
     if (USIS(EMSUART_UART) & ((1 << UIBD))) { // BREAK detection = End of EMS data block
         USC0(EMSUART_UART) &= ~(1 << UCBRK);  // reset tx-brk
-        if (emsTxBufIdx < emsTxBufLen) {      // irq tx_mode is interrupted by <brk>
-            emsTxBufIdx = emsTxBufLen + 1;    // stop tx
-            // drop_next_rx = true;              // we have trash in buffer
+        if (emsTxBufLen > 0) {                // timer tx_mode is interrupted by <brk>
+            emsTxBufLen  = 0;
+            drop_next_rx = true;
         }
         USIC(EMSUART_UART) = (1 << UIBD); // INT clear the BREAK detect interrupt
         length             = 0;
@@ -89,6 +89,9 @@ void ICACHE_FLASH_ATTR EMSuart::emsuart_recvTask(os_event_t * events) {
 
 // ISR to Fire when Timer is triggered
 void ICACHE_RAM_ATTR EMSuart::emsuart_tx_timer_intr_handler() {
+    if (emsTxBufLen == 0) {
+        return;
+    }
     emsTxBufIdx++;
     if (emsTxBufIdx < emsTxBufLen) {
         USF(EMSUART_UART) = emsTxBuf[emsTxBufIdx];
@@ -98,7 +101,8 @@ void ICACHE_RAM_ATTR EMSuart::emsuart_tx_timer_intr_handler() {
         timer1_write(EMSUART_TX_BRK_TIMER);
     } else {
         USC0(EMSUART_UART) &= ~(1 << UCBRK); // reset <BRK>
-        sending_ = false;
+        sending_    = false;
+        emsTxBufLen = 0;
     }
 }
 
@@ -279,7 +283,7 @@ uint16_t ICACHE_FLASH_ATTR EMSuart::transmit(uint8_t * buf, uint8_t len) {
 
     /*
      * Logic for tx_mode of 1
-     * based on code from https://github.com/proddy/EMS-ESP/issues/103 by @susisstrolch
+     * based on original code from https://github.com/proddy/EMS-ESP/issues/103 by @susisstrolch
      * 
      * Logic:
      * we emit the whole telegram, with Rx interrupt disabled, collecting busmaster response in FIFO.