From ee9b26ecfa86fa33dc374f19d7779e9bc066ac7b Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Sun, 12 Aug 2018 16:15:03 +0200
Subject: [PATCH] 6.1.1.5 - Fix Pow R2 and S31

Fix some Pow R2 and S31 checksum errors using optimized re-sync
---
 sonoff/_changelog.ino     |  7 ++++--
 sonoff/sonoff_version.h   |  2 +-
 sonoff/xdrv_03_energy.ino | 50 +++++++++++++++++++--------------------
 3 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/sonoff/_changelog.ino b/sonoff/_changelog.ino
index 1aa01acaf..b985976c8 100644
--- a/sonoff/_changelog.ino
+++ b/sonoff/_changelog.ino
@@ -1,6 +1,9 @@
-/* 6.1.1.4
+/* 6.1.1.5
+ * Fix some Pow R2 and S31 checksum errors using optimized re-sync
+ *
+ * 6.1.1.4
  * Change version representation from 1.1.1a to 1.1.1.1 for better change reference
- * 
+ *
  * 6.1.1c
  * Add iFan02 Fanspeed + and Fanspeed - command options (#3415)
  * Fix some Pow R2 and S31 checksum errors (#3425)
diff --git a/sonoff/sonoff_version.h b/sonoff/sonoff_version.h
index 9ce29bcea..534ed4d7c 100644
--- a/sonoff/sonoff_version.h
+++ b/sonoff/sonoff_version.h
@@ -20,6 +20,6 @@
 #ifndef _SONOFF_VERSION_H_
 #define _SONOFF_VERSION_H_
 
-#define VERSION  0x06010104
+#define VERSION  0x06010105
 
 #endif  // _SONOFF_VERSION_H_
diff --git a/sonoff/xdrv_03_energy.ino b/sonoff/xdrv_03_energy.ino
index 5fef4631e..8a5e38eff 100644
--- a/sonoff/xdrv_03_energy.ino
+++ b/sonoff/xdrv_03_energy.ino
@@ -307,7 +307,6 @@ void CseReceived()
   //  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
   // 55 5A 02 F7 60 00 03 AB 00 40 10 02 60 5D 51 A6 58 03 E9 EF 71 0B 7A 36
   // Hd Id VCal---- Voltage- ICal---- Current- PCal---- Power--- Ad CF--- Ck
-  AddLogSerial(LOG_LEVEL_DEBUG_MORE);
 
   uint8_t header = serial_in_buffer[0];
   if ((header & 0xFC) == 0xFC) {
@@ -315,14 +314,6 @@ void CseReceived()
     return;
   }
 
-  // Calculate checksum
-  uint8_t checksum = 0;
-  for (byte i = 2; i < 23; i++) checksum += serial_in_buffer[i];
-  if (checksum != serial_in_buffer[23]) {
-    AddLog_P(LOG_LEVEL_DEBUG, PSTR("CSE: " D_CHECKSUM_FAILURE));
-    return;
-  }
-
   // Get chip calibration data (coefficients) and use as initial defaults
   if (HLW_UREF_PULSE == Settings.energy_voltage_calibration) {
     long voltage_coefficient = 191200;  // uSec
@@ -392,24 +383,33 @@ bool CseSerialInput()
   if (cse_receive_flag) {
     serial_in_buffer[serial_in_byte_counter++] = serial_in_byte;
     if (24 == serial_in_byte_counter) {
-      CseReceived();
-      cse_receive_flag = 0;
-      return 1;
+      AddLogSerial(LOG_LEVEL_DEBUG_MORE);
+      uint8_t checksum = 0;
+      for (byte i = 2; i < 23; i++) { checksum += serial_in_buffer[i]; }
+      if (checksum == serial_in_buffer[23]) {
+        CseReceived();
+        cse_receive_flag = 0;
+        return 1;
+      } else {
+        AddLog_P(LOG_LEVEL_DEBUG, PSTR("CSE: " D_CHECKSUM_FAILURE));
+        do {                                  // Sync buffer with data (issue #1907 and #3425)
+          memmove(serial_in_buffer, serial_in_buffer +1, 24);
+          serial_in_byte_counter--;
+        } while ((serial_in_byte_counter > 1) && (0x5A != serial_in_buffer[1]));
+        if (0x5A == serial_in_buffer[1]) {
+          AddLog_P(LOG_LEVEL_DEBUG, PSTR("CSE: Fixed out-of-sync"));
+          serial_in_byte_counter++;
+        } else {
+          cse_receive_flag = 0;
+          serial_in_byte_counter = 0;
+        }
+      }
     }
   } else {
-    if ((0x5A == serial_in_byte) && (serial_in_byte_counter)) {  // 0x5A - Packet header 2
-      if ((0x55 == serial_in_buffer[serial_in_byte_counter -1]) ||
-          (0xAA == serial_in_buffer[serial_in_byte_counter -1]) ||
-          (serial_in_buffer[serial_in_byte_counter -1] > 0xF0)) {
-        if (serial_in_byte_counter > 1) {                        // Sync buffer with data (issue #1907 and #3425)
-          serial_in_buffer[0] = serial_in_buffer[--serial_in_byte_counter];
-          serial_in_byte_counter = 1;
-          AddLog_P(LOG_LEVEL_DEBUG, PSTR("CSE: Fixed out-of-sync"));
-        }
-        cse_receive_flag = 1;
-      } else {
-        serial_in_byte_counter = 0;
-      }
+    if ((0x5A == serial_in_byte) && (1 == serial_in_byte_counter)) {  // 0x5A - Packet header 2
+      cse_receive_flag = 1;
+    } else {
+      serial_in_byte_counter = 0;
     }
     serial_in_buffer[serial_in_byte_counter++] = serial_in_byte;
   }