title: Arduino Pro Mini IDE 1.8.4 avrdude: stk500recv(): programmer is not responding
body: <p>I was working on a project that I started a few months ago, and uploading seemed OK until randomly everything stopped. I've updated the IDE to the latest version (1.8.4), updated the Driver (USBTinyISP), disabled/enabled the COM port, tried multiple pro mini's, uploading example sketches, changed usb ports, and enabled verbose output during upload. What's weird is I can see the old serial monitor data printing from my previous upload changes this morning, so I know communication is working. The following is the message displayed after attempting to upload the sketch to the board.</p>
  
  <pre><code>Arduino: 1.8.4 (Windows 8.1), Board: "Arduino Pro or Pro Mini, ATmega168 (3.3V, 8 MHz)"
  
  Archiving built core (caching) in: C:\Users\pxb07\AppData\Local\Temp\arduino_cache_814882\core\core_arduino_avr_pro_cpu_8MHzatmega168_0c812875ac70eb4a9b385d8fb077f54c.a
  Sketch uses 3284 bytes (22%) of program storage space. Maximum is 14336 bytes.
  Global variables use 335 bytes (32%) of dynamic memory, leaving 689 bytes for local variables. Maximum is 1024 bytes.
  C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf -v -patmega168 -carduino -PCOM8 -b19200 -D -Uflash:w:C:\Users\pxb07\AppData\Local\Temp\arduino_build_381498/SoftwareSerialExample.ino.hex:i 
  
  avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
           Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
           Copyright (c) 2007-2014 Joerg Wunsch
  
           System wide configuration file is "C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf"
  
           Using Port                    : COM8
           Using Programmer              : arduino
           Overriding Baud Rate          : 19200
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x28
  avrdude: stk500_recv(): programmer is not responding
  avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x28
  
  avrdude done.  Thank you.
  
  Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
  
  This report would have more information with
  "Show verbose output during compilation"
  option enabled in File -&gt; Preferences.
  </code></pre>