I am using an Arduino UNO R3 and an IDE of 1.8.4. Laptop is Win7 64bit, 8Gb of ram, i7 quad Laptop is MSI GE70 brand. To answer your questions above, the COM port is 3, no, the com port has not changed, and yes I did test the communication using the serial monitor (see description below). After my last post, I ordered a bluetooth module to see if by bypassing the pc version of the dropController, I would have better luck. Before installing the bluetooth module on 11/18, I thought I would attempt to use the pc version, and it ran okay. I managed to get a total of 560 images and only had a few difficulties. Typically, the dropcontroller would run `0-30 cycles before failure (message was “No reply received from dropController”). After resetting the Arduino, and opening the program again it would function satisfactorily for another batch of shots. It did manage to loop for 100 cycles one time and 56 another time. Today I again planned to run another series of shots, but cannot get more than one cycle before getting the message “No reply received from dropController”. When I clear that popup message, the popup “Unhandled error…” appears. Attempting to setup with the bluetooth module, has been a complete failure, as it will not connect to my android app even though the module will pair with the phone. I have reset the sketch back to the device =1, recompiled and uploaded again, and experience the same difficulty as described above. I also reset everything and attempted to get a response to the “hello” and “version” using the serial monitor with no response. I can, however, get a single cycle to run with the pc version before failure. Would a Windows 10 laptop function better ?