diff --git a/src/cfg.c b/src/cfg.c
index 545410c..233c82a 100644
--- a/src/cfg.c
+++ b/src/cfg.c
@@ -50,7 +50,7 @@ cfg_t cfg;
 /* Configuration error message */
 char cfg_err[INTBUFSIZE + 1];
 
-#define CFG_ERR(s, v) snprintf(cfg_err, INTBUFSIZE, s, v)
+#define CFG_ERR(...) snprintf(cfg_err, INTBUFSIZE, __VA_ARGS__)
 
 /*
  * Setting up config defaults
@@ -232,7 +232,7 @@ cfg_handle_param(char *name, char *value)
   {
     if (!strlen(value))
     {
-      CFG_ERR("missing logfile value", value);
+      CFG_ERR("missing logfile value");
       return 0;
     }
     else if (*value != '/')
diff --git a/src/conn.c b/src/conn.c
index 9077f92..5266e2c 100644
--- a/src/conn.c
+++ b/src/conn.c
@@ -245,8 +245,6 @@ conn_write(int d, void *buf, size_t nbytes, int istty)
 {
   int rc;
   fd_set fs;
-  struct timeval ts, tts;
-  long delay;
 
 #ifdef TRXCTL
   if (istty && cfg.trxcntl != TRX_ADDC)
@@ -266,7 +264,8 @@ conn_write(int d, void *buf, size_t nbytes, int istty)
 #ifdef TRXCTL
   if (istty && cfg.trxcntl != TRX_ADDC )
   {
-    tty_delay(DV(nbytes, tty.bpc, cfg.ttyspeed));
+    // one char more delay to prevent too early GPIO switch on some HW
+    tty_delay(DV((nbytes + 1), tty.bpc, cfg.ttyspeed));
     tty_set_rx(d);
   }
 #endif
@@ -839,7 +838,7 @@ conn_loop(void)
               if (curconn->ctr >= MB_DATA_NBYTES)
               {
                 /* compute request data length for fc 15/16 */
-                unsigned int len;
+                unsigned int len = 0;
                 switch (MB_FRAME(curconn->buf, MB_FCODE))
                 {
                   case 15: /* Force Multiple Coils */
diff --git a/src/main.c b/src/main.c
index 630b0fa..f122f42 100644
--- a/src/main.c
+++ b/src/main.c
@@ -194,7 +194,7 @@ main(int argc, char *argv[])
   while ((rc = getopt(argc, argv,
                "dh"
 #ifdef TRXCTL
-               "ty:Y:"
+               "try:Y:"
 #endif
 #ifdef HAVE_TIOCRS485
                "S"