Remove serial flush and stop debug

sw/include/blacksasi.h

@@ -10,7 +10,7 @@
 
 #define LOG_FILENAME "LOG.txt"
 
-#define DEBUG            1      // 0:No debug information output
+#define DEBUG            0      // 0:No debug information output
                                 // 1: Debug information output to USB Serial
                                 // 2: Debug information output to LOG.txt (slow)
 

sw/src/main.cpp

@@ -685,8 +685,6 @@ inline byte readHandshake(void)
 inline void writeHandshake(byte d)
 {
   // This has a 400ns bus settle delay built in. Not optimal for multi-byte transfers.
-  serial.flush();
-
   GPIOD->regs->BSRR = db_bsrr[d]; // setup DB,DBP (160ns)
   TRANSCEIVER_IO_SET(vDTD,DB_OUTPUT)
   TRANSCEIVER_IO_SET(vIND,TR_OUTPUT)