Error: the selected serial port does not exist or your board is not connected

Support
1

An error happens during coding blinks. I tried plugging in and out, but it didn’t work. I tried restarting arduino, but it didn’t work as well.

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:01:35

             Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
             Copyright (c) 2007-2014 Joerg Wunsch

             System wide configuration file is "/Applications/Arduino.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf"
             User configuration file is "/Users/liushiyun/.avrduderc"
             User configuration file does not exist or is not a regular file, skipping

             Using Port                    : usb
             Using Programmer              : usbtiny
             Setting bit clk period        : 3.0
    avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)

    avrdude done.  Thank you.

    the selected serial port 
     does not exist or your board is not connected```
2

Oh, unplugging the usb and restarting my computer works. Wonder if there are any other solutions that don’t need to restart.

3

Sometimes the programming jig is not firmly pressed on the Blink and causes that error. I’ve found that the reason for programming failure is usually:

  1. Re-press (not too hard) jig on Blink so spring loaded pins make solid contact
  2. Blink battery too low (check voltage between screw and reset pin - should be at least 2.7v)
  3. Make sure USB connection working properly to PC/Mac so ISP is seen.