diff --git a/src/ZeDMDComm.cpp b/src/ZeDMDComm.cpp
index c6eb013..7346cee 100644
--- a/src/ZeDMDComm.cpp
+++ b/src/ZeDMDComm.cpp
@@ -498,9 +498,9 @@ bool ZeDMDComm::Handshake(char* pDevice)
   sp_nonblocking_write(m_pSerialPort, data, ZEDMD_COMM_MAX_SERIAL_WRITE_AT_ONCE);
 
   // For Linux and macOS, 200ms seem to be sufficient. But some Windows installations require a longer sleep here.
-  std::this_thread::sleep_for(std::chrono::milliseconds(500));
+  std::this_thread::sleep_for(std::chrono::milliseconds(200));
   memset(data, 0, ZEDMD_COMM_MAX_SERIAL_WRITE_AT_ONCE);
-  sp_blocking_read(m_pSerialPort, data, 20, ZEDMD_COMM_SERIAL_READ_TIMEOUT);
+  int result = sp_blocking_read(m_pSerialPort, data, 20, ZEDMD_COMM_SERIAL_READ_TIMEOUT);
 
   if (memcmp(data, CTRL_CHARS_HEADER, 4) == 0)
   {
@@ -681,10 +681,9 @@ bool ZeDMDComm::SendChunks(uint8_t* pData, uint16_t size)
     (defined(__APPLE__) && ((defined(TARGET_OS_IOS) && TARGET_OS_IOS) || (defined(TARGET_OS_TV) && TARGET_OS_TV))) || \
     defined(__ANDROID__))
 
-  uint8_t ack[1] = {0};
+  uint8_t ack[CTRL_CHARS_HEADER_SIZE + 1] = {0};
   int status = 0;
   uint16_t sent = 0;
-  uint8_t numCtrlCharsFound = 0;
 
   while (sent < size && !m_stopFlag.load(std::memory_order_relaxed))
   {
@@ -717,32 +716,17 @@ bool ZeDMDComm::SendChunks(uint8_t* pData, uint16_t size)
     }
     sent += status;
 
-    numCtrlCharsFound = 0;
-    while (!m_stopFlag.load(std::memory_order_relaxed) && numCtrlCharsFound < CTRL_CHARS_HEADER_SIZE)
-    {
-      status = sp_nonblocking_read(m_pSerialPort, ack, 1);
-      if (status == 1)
-      {
-        // Detect 5 consecutive start bits
-        if (ack[0] == CTRL_CHARS_HEADER[numCtrlCharsFound])
-        {
-          numCtrlCharsFound++;
-        }
-        else
-        {
-          numCtrlCharsFound = 0;
-        }
-      }
-    }
+    status = sp_blocking_read(m_pSerialPort, ack, CTRL_CHARS_HEADER_SIZE + 1, ZEDMD_COMM_SERIAL_READ_TIMEOUT);
 
-    status = sp_blocking_read(m_pSerialPort, ack, 1, ZEDMD_COMM_SERIAL_READ_TIMEOUT);
-    if (ack[0] == 'F')
+    if (status < CTRL_CHARS_HEADER_SIZE + 1 || memcmp(ack, CTRL_CHARS_HEADER, CTRL_CHARS_HEADER_SIZE) != 0 ||
+        ack[CTRL_CHARS_HEADER_SIZE] == 'F')
     {
       m_fullFrameFlag.store(true, std::memory_order_release);
-      Log("Full frame requested by ZeDMD because of internal error");
+      Log("Full frame forced, error %d", status);
       return false;
     }
-    else if (ack[0] != 'A')
+
+    if (ack[CTRL_CHARS_HEADER_SIZE] != 'A')
     {
       m_fullFrameFlag.store(true, std::memory_order_release);
       Log("Full frame forced, error %d", status);