I was recently told I should probably update my printer's firmware from the current version (ANET_A8_20160701V2.0) to Marlin (going to use v1.1.9). To do this, I dutifully downloaded both Pronterface and RepetierHost trying to connect with either one of them to my printer. I've checked the Device Mangler (Manager) and found the USB does connect and is recognized on COM5, yet neither software are connecting. The software sees COM5 as active as well, but I get back an error stating "access is denied" for some reason. What might I be doing wrong?
After some trial and error, I discovered you need to set the baud rate to 115200 in the printer settings. I went through and tried each of the baud settings available until it connected. Glad I started with Pronterface, as RepetierHost has a lot longer baud list :o) Setting the baud rate is not inuitive as to the issue, as getting back "access denied" to me implied something else was going on. After that, was able to run direct commands to the printer through the USB port without issues.