Updated OTW script

- Added argparse for argument parsing.
- The ExpressLink version is read before OTW and EOL is chosen based on version.
- Starting with v1.X.X of ExpressLink, the module sends an OK message upon entering OTW mode.
  The script has been updated to accomodate this change in behaviour.

tools/otw.py

@@ -4,11 +4,31 @@
 import os
 import serial
 import time
+import re
+import argparse
 
+semver = {"major": '0', "minor": '0', "patch": '0'}
+
+def get_parser():
+    parser = argparse.ArgumentParser(prog='OTW Update Script',
+    description='''This script can be used to
+    switch between firmware versions on Espressif ExpressLink modules/devkits. 
+    The firmware upgrade/downgrade is carried out over the same
+    UART interface that accepts AT commands.
+    ''')
+    parser.add_argument('port', help="UART Serial Port")
+    parser.add_argument('filepath', help="Firmware binary filepath")
+    parser.add_argument('--blocksize', '-b', type=int, help="Size of each block of the OTW firmware update (the default is 2048)", default=2048)
+    return parser
+
+def read_semver(input_string):
+    global semver
+    regex = r'''(\d+(?:\.\d+)*)'''
+    version_string = re.findall(regex, input_string)[0]
+    semver = dict(zip(semver.keys(), version_string.split('.')))
 
 def wait_for_ok_complete():
     data = ser.readline();
-    print(data)
     if not data:
         print("Timeout reading over serial");
     if data == str.encode("OK COMPLETE\n"):
@@ -17,43 +37,60 @@ def wait_for_ok_complete():
 
 def wait_for_ok():
     data = ser.readline();
+    if int(semver["major"]) > 0:
+        ok_string = "OK\r\n"
+    else:
+        ok_string = "OK\n"
     if not data:
         print("Timeout reading over serial");
-    if data == str.encode("OK\n"):
+    if data == str.encode(ok_string):
         return "OK"
     return "ERR"
 
+def otw(port, filepath, blocksize):
+    filestat = os.stat(filepath)
+    print(f"File size {filestat.st_size}")
 
-if __name__ == "__main__":
-    if (len(sys.argv) < 3):
-        print(f"Usage: {sys.argv[0]} <portname> <filename>")
-        sys.exit()
-    port = sys.argv[1]
-    filename = sys.argv[2]
+    global ser
+    ser = serial.Serial(port, 115200, timeout=60)
+
+    cmd = "AT+CONF? Version\n"
+    ser.write(str.encode(cmd))
 
+    cmd = "AT+OTW "+ str(filestat.st_size) + f",{blocksize}\n"
+    ser.write(str.encode(cmd))
+    data = ser.readline();
+    if data:
+        read_semver(data.decode())
+    else:
+        print("Timeout reading over serial");
+
+    stream = open(filepath, 'rb')
+    total_data_written = 0;
 
-filestat = os.stat(filename)
-print(f"File size {filestat.st_size}")
+    if int(semver["major"]) > 0:
+        ret = wait_for_ok()
+        if ret != "OK":
+                print("\nError in OTW update")
+                sys.exit()
 
-ser = serial.Serial(port, 115200, timeout=60)
-cmd = "AT+OTW "+ str(filestat.st_size) + ",2048\n"
-ser.write(str.encode(cmd))
+    while True:
+        data = stream.read(blocksize);
+        if not data:
+            break;
+        ser.write(data)
+        total_data_written += len(data)
+        ret = wait_for_ok()
+        percent_str = 'Uploaded ' + str(round(total_data_written * 100 / filestat.st_size, 2)) + '%'
+        sys.stdout.write('\r%s' % percent_str)
+        if ret != "OK":
+            print("\nError in OTW update")
+            break
 
-stream = open(filename, 'rb')
+    ret = wait_for_ok_complete()
+    print("\nDone...")
 
-total_data_written = 0;
-while True:
-    data = stream.read(2048);
-    if not data:
-        break;
-    ser.write(data)
-    total_data_written += len(data)
-    ret = wait_for_ok()
-    percent_str = 'Uploaded ' + str(round(total_data_written * 100 / filestat.st_size, 2)) + '%'
-    sys.stdout.write('\r%s' % percent_str)
-    if ret != "OK":
-        print("\nError in OTW update")
-        break
-
-ret = wait_for_ok_complete()
-print("\nDone...")
+if __name__ == "__main__":
+    parser = get_parser()
+    args = parser.parse_args()
+    otw(args.port, args.filepath, args.blocksize)