SpaceDragon Robot Programmer turns robot arm motion into something you can see and edit directly.

Instead of hand-writing servo commands, you drag command blocks onto a timeline. Horizontal position is when a movement happens, vertical lane is which servo. Blocks stacked at the same point run simultaneously; blocks that overlap run overlapped. Every angle is an absolute target position, so moving a block along the timeline never changes where the arm ends up.

The app knows the physical limits of your arm. Before it will generate anything, it sweeps the entire movement plan — sampling every joint every 20 ms — and checks the mechanical constraints across the whole trajectory, not just at the target angles. That matters: two movements that are each perfectly legal on their own can still swing the arm through an illegal pose while both servos are travelling. When that happens you get the exact time window, the angles involved, and the range the offending axis needs to be in.

When the plan is valid, the Code page produces a complete, commented Arduino sketch you can copy straight into the Arduino IDE.

Included robot: Dragon-Arm Demo — three axes plus a servo gripper, MG996R servos on a PCA9685 PWM expander.