diff --git a/system/ymodem/rb_main.c b/system/ymodem/rb_main.c
index 1beb8c2a2..6dd084084 100644
--- a/system/ymodem/rb_main.c
+++ b/system/ymodem/rb_main.c
@@ -330,6 +330,12 @@ static void show_usage(FAR const char *progname)
   fprintf(stderr,
           "\t-t|--threshold <size>: Threshold for writing asynchronously."
           "Threshold must be less than or equal buffersize, Default: 0kB\n");
+  fprintf(stderr,
+          "\t-i|--interval <time>: Waiting interval for transmitting data."
+          "Max:255 Min:1 Default:15 unit: 100 milliseconds\n");
+  fprintf(stderr,
+          "\t-r|--retry <retry>: Number of retries."
+          "Will try <retry> times to transmitting, Default:100\n");
   fprintf(stderr,
           "\t-k <size>: Use a custom size to tansfer, Default: 1kB\n");
 
@@ -352,13 +358,17 @@ int main(int argc, FAR char *argv[])
       {"buffersize", 1, NULL, 'b'},
       {"skip_prefix", 1, NULL, 'p'},
       {"skip_suffix", 1, NULL, 's'},
-      {"threshold", 1, NULL, 't'}
+      {"threshold", 1, NULL, 't'},
+      {"interval", 1, NULL, 'i'},
+      {"retry", 1, NULL, 'r'},
     };
 
   memset(&priv, 0, sizeof(priv));
   memset(&ctx, 0, sizeof(ctx));
-  while ((ret = getopt_long(argc, argv, "b:d:f:hk:p:s:t:", options, NULL))
-         != ERROR)
+  ctx.interval = 15;
+  ctx.retry = 100;
+  while ((ret = getopt_long(argc, argv, "b:d:f:hk:p:s:t:i:r:",
+                            options, NULL)) != ERROR)
     {
       switch (ret)
         {
@@ -391,6 +401,12 @@ int main(int argc, FAR char *argv[])
           case 't':
             priv.threshold = atoi(optarg) * 1024;
             break;
+          case 'i':
+            ctx.interval = atoi(optarg);
+            break;
+          case 'r':
+            ctx.retry = atoi(optarg);
+            break;
 
           case '?':
           default:
diff --git a/system/ymodem/sb_main.c b/system/ymodem/sb_main.c
index 22d0676f9..9b84ad41c 100644
--- a/system/ymodem/sb_main.c
+++ b/system/ymodem/sb_main.c
@@ -275,6 +275,12 @@ static void show_usage(FAR const char *progname)
   fprintf(stderr,
           "\t-b|--buffersize <size>: Asynchronously send buffer size."
           "If greater than 0, accept data asynchronously, Default: 0kB\n");
+  fprintf(stderr,
+          "\t-i|--interval <time>: Waiting interval for transmitting data."
+          "Max:255 Min:1 Default:15 unit: 100 milliseconds\n");
+  fprintf(stderr,
+          "\t-r|--retry <retry>: Number of retries."
+          "Will try <retry> times to transmitting, Default:100\n");
   fprintf(stderr,
           "\t-k <size>: Use a custom size to tansfer, Default: 1kB\n");
 
@@ -294,10 +300,14 @@ int main(int argc, FAR char *argv[])
   struct option options[] =
     {
       {"buffersize", 1, NULL, 'b'},
+      {"interval", 1, NULL, 'i'},
+      {"retry", 1, NULL, 'r'},
     };
 
   memset(&priv, 0, sizeof(priv));
   memset(&ctx, 0, sizeof(ctx));
+  ctx.interval = 15;
+  ctx.retry = 100;
   while ((ret = getopt_long(argc, argv, "b:d:k:h", options, NULL))
          != ERROR)
     {
@@ -317,6 +327,13 @@ int main(int argc, FAR char *argv[])
               }
 
             break;
+          case 'i':
+            ctx.interval = atoi(optarg);
+            break;
+          case 'r':
+            ctx.retry = atoi(optarg);
+            break;
+
           case 'h':
           case '?':
           default:
diff --git a/system/ymodem/sbrb.py b/system/ymodem/sbrb.py
index 7c8dd191f..8fdca2f70 100755
--- a/system/ymodem/sbrb.py
+++ b/system/ymodem/sbrb.py
@@ -21,7 +21,6 @@ import binascii
 import datetime
 import io
 import os
-import signal
 import sys
 import termios
 
@@ -54,47 +53,35 @@ def format_time(seconds):
     return time
 
 
-class Timeout(Exception):
-    pass
-
-
-def timeout_handle(signum, frame):
-    sys.stderr.write("timeout!\n")
-    sys.stderr.flush()
-    raise Timeout("Timeout")
-
-
 def ymodem_stdread(size):
     fd = sys.stdin.fileno()
     old_settings = termios.tcgetattr(fd)
-    signal.signal(signal.SIGALRM, timeout_handle)
-    signal.alarm(3)
-    try:
-        new_settings = termios.tcgetattr(fd)
-        new_settings[3] &= ~(termios.ICANON | termios.ECHO)
-        termios.tcsetattr(fd, termios.TCSADRAIN, new_settings)
-        data = sys.stdin.buffer.read(size)
-        sys.stdin.flush()
-        return data
-    except Timeout:
-        return
-    finally:
-        signal.alarm(0)
-        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
+    new_settings = termios.tcgetattr(fd)
+    new_settings[3] &= ~(termios.ICANON | termios.ECHO)
+    termios.tcsetattr(fd, termios.TCSADRAIN, new_settings)
+    data = sys.stdin.buffer.read(size)
+    termios.tcflush(sys.stdin, termios.TCIFLUSH)
+    sys.stdin.flush()
+    termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
+    return data
 
 
 def ymodem_stdwrite(data):
     fd = sys.stdout.fileno()
     old_settings = termios.tcgetattr(fd)
-    try:
-        new_settings = termios.tcgetattr(fd)
-        new_settings[3] &= ~(termios.ICANON | termios.ECHO)
-        termios.tcsetattr(fd, termios.TCSADRAIN, new_settings)
-        data = sys.stdout.buffer.write(data)
-        sys.stdout.flush()
-        return data
-    finally:
-        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
+    new_settings = termios.tcgetattr(fd)
+    new_settings[3] &= ~(termios.ICANON | termios.ECHO)
+    termios.tcsetattr(fd, termios.TCSADRAIN, new_settings)
+    data = sys.stdout.buffer.write(data)
+    termios.tcflush(sys.stdout, termios.TCIFLUSH)
+    sys.stdout.flush()
+    termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
+    return data
+
+
+def ymodem_stdclear():
+    sys.stdin.flush()
+    sys.stdout.flush()
 
 
 def ymodem_stdprogress(data):
@@ -115,6 +102,13 @@ def ymodem_ser_write(data):
     fd_serial.flush()
 
 
+def ymodem_ser_clear():
+    global fd_serial
+
+    fd_serial.reset_input_buffer()
+    fd_serial.reset_output_buffer()
+
+
 def calc_crc16(data, crc=0):
     crctable = [
         0x0000,
@@ -388,15 +382,21 @@ class ymodem:
         read=ymodem_stdread,
         write=ymodem_stdwrite,
         progress=ymodem_stdprogress,
+        clear=ymodem_stdclear,
         timeout=100,
+        maxretry=RETRIESMAX,
         debug="",
         customsize=0,
     ):
         self.read = read
         self.write = write
+        self.clear = clear
         self.timeout = timeout
+        self.maxretry = maxretry
         self.progress = progress
         self.customsize = customsize
+        self.retries = 0
+
         if debug != "":
             self.debugfd = open(debug, "w+")
         else:
@@ -460,24 +460,28 @@ class ymodem:
 
         return 0
 
+    def send_handshake(self):
+        self.write(CRC)
+        while self.retries < self.maxretry:
+            chunk = self.read(1)
+            if chunk == CRC:
+                return True
+            else:
+                self.retries += 1
+                self.clear()
+
+        self.progress("too many retries\n")
+        return False
+
     def send(self, filelist):
-        retries = 0
         need_sendfile_num = len(filelist)
         cnt = 0
         now = datetime.datetime.now()
         base = float(int(now.timestamp() * 1000)) / 1000
         totolbytes = 0
 
-        while retries < 10:
-            self.write(CRC)
-            chunk = self.read(1)
-            if chunk == CRC:
-                break
-            else:
-                retries += 1
-
-        if retries == 10:
-            return False
+        if not self.send_handshake():
+            return -EINVAL
 
         while need_sendfile_num != 0:
             now = datetime.datetime.now()
@@ -485,13 +489,10 @@ class ymodem:
             self.init_pkt()
             self.head = SOH
             filename = os.path.basename(filelist[cnt])
-
-            self.progress("name:" + filename)
             self.data = filename.encode("utf-8")
             self.data = self.data + bytes([0x00] * 1)
             filesize = os.path.getsize(filelist[cnt])
             sendfilesize = 0
-            self.progress(" filesize:%d\n" % (filesize))
             self.data = self.data + str(filesize).encode("utf-8")
             self.data = self.data.ljust(self.get_pkt_size(), b"\x00")
             self.send_pkt()
@@ -500,14 +501,21 @@ class ymodem:
             if ret == -EAGAIN:
                 continue
             elif ret == -EINVAL:
+                if self.send_handshake():
+                    continue
                 return ret
 
             ret = self.recv_cmd(CRC)
             if ret == -EAGAIN:
                 continue
             elif ret == -EINVAL:
+                if self.send_handshake():
+                    continue
                 return ret
 
+            self.progress("name:" + filename)
+            self.progress(" filesize:%d\n" % (filesize))
+
             self.add_seq()
             readfd = open(filelist[cnt], "rb")
             self.progress("     ")
@@ -656,7 +664,6 @@ class ymodem:
         return 0
 
     def recv(self):
-        retries = 0
         now = datetime.datetime.now()
         base = float(int(now.timestamp() * 1000)) / 1000
         totolbytes = 0
@@ -673,12 +680,12 @@ class ymodem:
                 continue
 
             elif ret < 0:
-                if retries > RETRIESMAX:
+                if self.retries > self.maxretry:
                     return -1
 
                 self.progress("recv ret %d\n" % ret)
                 self.debug("recv frist packet\n")
-                retries += 1
+                self.retries += 1
                 continue
 
             filename = bytes.decode(self.data.split(b"\x00")[0], "utf-8")
@@ -699,9 +706,9 @@ class ymodem:
                 ret = self.recv_packet()
                 if ret < 0:
                     self.debug("recv a bad data packet\n")
-                    if retries > RETRIESMAX:
+                    if self.retries > self.maxretry:
                         return -1
-                    retries += 1
+                    self.retries += 1
                     continue
 
                 size = 0
@@ -791,6 +798,13 @@ if __name__ == "__main__":
             """,
     )
 
+    parser.add_argument(
+        "--maxretry",
+        type=int,
+        default=RETRIESMAX,
+        help="This opthin set max retry for transmission",
+    )
+
     parser.add_argument(
         "--debug", help="This opthin is save debug log on host", default=""
     )
@@ -821,9 +835,13 @@ if __name__ == "__main__":
             customsize=args.kblocksize * 1024,
             read=ymodem_ser_read,
             write=ymodem_ser_write,
+            clear=ymodem_ser_clear,
+            maxretry=args.maxretry,
         )
     else:
-        sbrb = ymodem(debug=args.debug, customsize=args.kblocksize * 1024)
+        sbrb = ymodem(
+            debug=args.debug, customsize=args.kblocksize * 1024, maxretry=args.maxretry
+        )
 
     if len(args.filelist) == 0:
         sbrb.progress("receiving\n")
diff --git a/system/ymodem/ymodem.c b/system/ymodem/ymodem.c
index 1f8cf6ff6..961af3a6c 100644
--- a/system/ymodem/ymodem.c
+++ b/system/ymodem/ymodem.c
@@ -60,8 +60,6 @@
 #define CAN           0x18  /* Two of these in succession aborts transfer */
 #define CRC           0x43  /* 'C' == 0x43, request 16-bit CRC */
 
-#define MAX_RETRIES   100
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -216,7 +214,7 @@ recv_packet:
       /* other errors, like ETIMEDOUT, EILSEQ, EBADMSG... */
 
       tcflush(ctx->recvfd, TCIOFLUSH);
-      if (++retries > MAX_RETRIES)
+      if (++retries > ctx->retry)
         {
           ymodem_debug("recv_file: too many errors, cancel!!\n");
           goto cancel;
@@ -340,7 +338,7 @@ static int ymodem_send_file(FAR struct ymodem_ctx_s *ctx)
   int ret;
 
   ymodem_debug("waiting handshake\n");
-  for (retries = 0; retries < MAX_RETRIES; retries++)
+  for (retries = 0; retries < ctx->retry; retries++)
     {
       ret = ymodem_recv_cmd(ctx, CRC);
       if (ret >= 0)
@@ -349,7 +347,7 @@ static int ymodem_send_file(FAR struct ymodem_ctx_s *ctx)
         }
     }
 
-  if (retries >= MAX_RETRIES)
+  if (retries >= ctx->retry)
     {
       ymodem_debug("waiting handshake error\n");
       return -ETIMEDOUT;
@@ -581,7 +579,7 @@ int ymodem_recv(FAR struct ymodem_ctx_s *ctx)
   tcgetattr(ctx->recvfd, &term);
   memcpy(&saveterm, &term, sizeof(struct termios));
   cfmakeraw(&term);
-  term.c_cc[VTIME] = 15;
+  term.c_cc[VTIME] = ctx->interval;
   term.c_cc[VMIN] = 255;
   tcsetattr(ctx->recvfd, TCSANOW, &term);
 
diff --git a/system/ymodem/ymodem.h b/system/ymodem/ymodem.h
index 6c66be7b6..d52b4934e 100644
--- a/system/ymodem/ymodem.h
+++ b/system/ymodem/ymodem.h
@@ -50,6 +50,8 @@ struct ymodem_ctx_s
   CODE int (*packet_handler)(FAR struct ymodem_ctx_s *ctx);
   size_t custom_size;
   FAR void *priv;
+  uint8_t interval;
+  int retry;
 
   /* Public data */