I just built a 3018CNC (from Banggood) and the included GrblControl and downloaded UGB both are seeing garbled returns from the machine. GrblControl promptly crashes, while UGB at least keeps running. It even fails using Putty terminal just sending an "$$" command. This is a small excerpt from UGB:
$0 = 10 (step pulse, usec)
$1 = 25 (step idle delay, msec)
$2OBšÑ•Á?port invert mask:00000000)
$3 = 0 (dir port invert mask:00000000)
$4 = 0 (step enable invert,½½±¥)
[Error] Error while processing response <<Idle,MPos:0.000,0 ‚‚b‚r‚‚‚bºA½Íé0.000,0.000,0.000>>
[Error] Error while processing response <<Idle,MPos:0 ‚‚b‚r‚‚‚b‚r‚‚‚bºA½Íé0.000, 0.000,0.000>>
[Error] Error while processing response <<Idle,MPos:0.000,0.000,0 ‚‚bºA½Íé0.000,0.000,0.000>>
I've tried setting the Port Properties under Device Manager to all three flow control options with no impact. Of course the kit didn't include any instructions beyond mechanical assembly.
Maybe the crystal that drives the control board is off frequency or something that I'll never find. I'll be pleasantly surprised if I even hear from Banggood support, let alone get useful help.