Scara Arm(2 link) on Marlin firmware making revolution when x <=0 and coordinates changes on y axis mean after passing 0 makes one more rotation. Note both arm can move 360 no obstacle inbetween in hardware.
SEE LOGS
Recv:19:57:07.686: X:0.00 Y:220.00 Z:0.00 Count A:150B:155 Z:0
Recv:19:57:07.688: SCARA Theta:90.00 Psi:90.12
Recv:19:57:15.210: X:0.00 Y:220.00 Z:0.00 Count A:150B:155 Z:0 (3)
Recv:19:57:15.210: SCARA Theta:90.00 Psi:90.12
Recv:19:57:28.232: X:0.00 Y:20.00 Z:0.00 Count A:290B:11 Z:0
Recv:19:57:28.232: SCARA Theta:174.00 Psi:6.40
Recv:19:57:33.356: X:-10.00 Y:20.00 Z:0.00 Count A:335B:56 Z:0
Recv:19:57:33.356: SCARA Theta:201.00 Psi:32.56
Recv:19:57:43.649: X:-10.00 Y:0.00 Z:0.00 Count A:446B:159 Z:0
Recv:19:57:43.649: SCARA Theta:267.59 Psi:92.44
Till here the theta is +ve and when it goes y passes axis it take one more rotation as per kinematics to -49 degree
Recv:19:57:49.740: X:-10.00 Y:-10.00 Z:0.00 Count A:-83B:-383 Z:0
Recv:19:57:49.743: SCARA Theta:-49.80 Psi:-222.67
Recv:19:57:54.751: X:-10.00 Y:-20.00 Z:0.00 Count A:-57B:-350 Z:0
Recv:19:57:54.751: SCARA Theta:-34.20 Psi:-203.49
Thank You : )
