The device is controlled by 3 byte commands sent via USB control transfers. Command format is byte0, byte1, byte2. Each byte controls a group of arm features. All motors could be controlled independently. Most commands start action which is continued until next action is signalled. Byte '00' universally used as stop action.
The first byte (Byte0) controls Gripper, Shoulder, Elbow and Wrist.
The bits of Byte0 are assigned as follows:
| Bit Positions | Joints | Rules |
|---|---|---|
| 1, 0 | Gripper | 00-do not move, 01-close, 10-open |
| 3, 2 | Wrist | 00-do not move, 01-move up, 10-move down |
| 5, 4 | Elbow | 00-do not move, 01-move up, 10-move down |
| 7, 6 | Shoulder | 00-do not move, 01-move up, 10-move down |
Note there is no '11' in the rule for any joint.
The combination of bits with different values in Byte0 achieves simultaneous controlling of the four joints.
The second byte (Byte1) controls Base.
The bits of Byte1 are assigned as follows:
| Bit Positions | Joints | Rules |
|---|---|---|
| 1, 0 | Base | 00-do not move, 01-rotate clockwise, 10-rotate anticlockwise |
Higher positioned bits are ignored.
The third byte (Byte2) controls LED light inside the gripper.
The bits of Byte2 are assigned as follows:
| Bit Positions | Joints | Rules |
|---|---|---|
| 0 | Light | 0-off, 1-on |
In a byte there are eight bits, which are usually indexed as follows:
