I have been working on a project watch which would work best if it is entirely sealed (to waterproof it). The watch may need future updates, but I will be unable to send code to it using a usb connector or isp programmer without opening the case. What is the best way to connect my PC with this watch wirelessly?

I gather that the serial ports are usually used to send code via the usb, and that most Bluetooth modules use serial coms to communicate with the Arduino.

The Arduino that I am using is an Arduino Pro Mini clone.

Any help will be greatly appreciated.

  • Go simple, and use light. IR-receiver or photo-transistor.
    – Gerben
    Mar 17, 2016 at 18:45
  • There actually exists an Arduino BT board. (arduino.cc/en/Main/ArduinoBoardBT) which should be extremely easy (virtual bt COM-port as if it was connected to a cable). I'm not sure how up to date or available the board is though.
    – Paul
    Mar 17, 2016 at 22:03
  • 1
    Alternatively, you could push a pin header through the box/casing, connect it, and cover it in hot glue. Which may be waterproof to some point.
    – Paul
    Mar 17, 2016 at 22:05

1 Answer 1


You could use ESP8266 and ESP-LINK firmware to update the arduino firmware over the wire. Its also enables you to debug it wirelessly. What it does is provide a serial link but over wifi. Just like connecting it via cable.

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