From 882244795b9bec1f2c86d596d4ab4ecd4346c8b9 Mon Sep 17 00:00:00 2001
From: Bryan Biedenkapp <gatekeep@gmail.com>
Date: Wed, 10 Apr 2024 21:43:16 -0400
Subject: [PATCH] fix support for incoming long frames;

---
 SerialPort.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/SerialPort.cpp b/SerialPort.cpp
index 2958f17..ec4ab79 100644
--- a/SerialPort.cpp
+++ b/SerialPort.cpp
@@ -82,12 +82,18 @@ void SerialPort::process()
         }
         else if (m_ptr == 1U) {
             // Handle the frame length
-            m_len = m_buffer[m_ptr] = c;
+            if (m_dblFrame) {
+                m_buffer[m_ptr] = c;
+                m_len = ((c & 0xFFU) << 8);
+            } else {
+                m_len = m_buffer[m_ptr] = c;
+            }
             m_ptr = 2U;
         }
         else if (m_ptr == 2U && m_dblFrame) {
             // Handle the frame length
-            m_len = m_buffer[m_ptr] = (c + 255U);
+            m_buffer[m_ptr] = c;
+            m_len = (m_len + (c & 0xFFU));
             m_ptr = 3U;
         }
         else {