From d15cc3e12a87f97f56b1076efc43c418ba8f4456 Mon Sep 17 00:00:00 2001
From: Dave Marples <dave@marples.net>
Date: Fri, 20 Sep 2024 22:44:09 +0100
Subject: [PATCH] Add COBS draining state to ensure fast resync

---
 Inc/cobs.h |  3 ++-
 Src/cobs.c | 10 +++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/Inc/cobs.h b/Inc/cobs.h
index 2b0827f7..a4199186 100644
--- a/Inc/cobs.h
+++ b/Inc/cobs.h
@@ -26,7 +26,8 @@ extern "C" {
 enum COBSPumpState
 {
     COBS_IDLE,
-    COBS_RXING
+    COBS_RXING,
+    COBS_DRAINING
 };
 
 struct Frame
diff --git a/Src/cobs.c b/Src/cobs.c
index be1c2930..36f4ae17 100644
--- a/Src/cobs.c
+++ b/Src/cobs.c
@@ -132,6 +132,14 @@ void COBSPump( struct COBS *t, const uint8_t *incoming, int len,
 
                 break;
 
+            case COBS_DRAINING:  // ---------------------------------------------------------------
+                if ( COBS_SYNC_CHAR == *fp )
+                {
+                    t->s = COBS_IDLE;
+                }
+
+                break;
+
             case COBS_RXING: // -------------------------------------------------------------------
                 t->intervalCount--;
 
@@ -160,7 +168,7 @@ void COBSPump( struct COBS *t, const uint8_t *incoming, int len,
                     if ( ( t->f.len > COBS_MAX_PACKET_LEN  ) || ( COBS_SYNC_CHAR == *fp ) )
                     {
                         t->error++;
-                        t->s = COBS_IDLE;
+                        t->s = COBS_DRAINING;
                     }
                     else
                     {