update readme

README.md

 
 ___
 
-modify __platformio.ini__
+__modify__ _platformio.ini_
 
 ```ini
 ; example platformio.ini
 
 ___
 
-__Upload compiled binary via uart__
+__upload compiled binary via uart__
 
 __note__: close serial port
 
 
 __open serial port to esp8266 and check Wi-Fi connection__
 
-monitor output:
 ```bash
+# monitor output:
 Ready
-IP address: 192.168.10.108
+IP address: # your local IP #
 ```
 __modify platformio.ini accordingly__
 ```ini
 framework = arduino
 
 upload_protocol = espota
-upload_port = 192.168.10.108
+upload_port = # your local IP #
 monitor_speed = 74880
 ```
 ___
 
-Process of updating
+__now you can upload new binaries via OTA__
 
-![ota flash layout](ota_flash.png)
+```bash
+$ pio run -t upload
+# or use upload button in vscode
+```
+
+__what`s happening can be observed with [debug_ser.py](debug_ser.py), _PySerial_ needed !__
+
+```bash
+$ python3 debug_ser.py
+
+# serial output:
+[OTA] Start updating sketch
+[OTA] Progress: 100%
+[OTA] End
+
+ets Jan  8 2013,rst cause:2, boot mode:(3,7)
+
+load 0x4010f000, len 3460, room 16
+tail 4
+chksum 0xcc
+load 0x3fff20b8, len 40, room 4 
+tail 4
+chksum 0xc9
+csum 0xc9
+v0004e770
+@cp:B0 # copying new binary into boot flash region
+ld
+
+[Program] Booting
+[Program] OTA and HTTPServer ready !
+[Program] IP address: 192.168.10.108
+```
+
+___
+
+__Process of updating__
 
-code for updating
+![ota flash layout](ota_flash.png)