End Effectors

The end point of the standard Dexter robot hardware is a replaceable "tool interface" It has a shape which makes it easy for other tools to be clicked on and off. There are "pogo pins" at the end for electrical connection.

The signals available to the end effector include power, ground, and whatever signals the main board has been configured to produce. Early versions supplied USB connection, some were configured to produce PWM type RC servo drive signals, but the standard going forward will be a new tool interface which incorporates 2 Dynamixel XL-320 servos and a Tinyscreen+ (ARM based, small OLED screen, 4 buttons, lots of IO). The Tinyscreen+ will listen on the servo bus and may return data there or via the dedicated return data line. To decode the Dynamixel V2.0 Protocol, a small serial filter routine can be added to standard Arduino code.

Signals from Dexter to the Tool Interface:

• Ground
• Logic power +5 Volts
• Supply power, regulated to Servo power voltage at the interface
• Servo data bus, bidirectional
• Return serial data

Multiple signals are available from the Tinyduino for many different purposes.

Known end effectors:

• Marker / Pen holder:
  http://hdrobotic.com/dexter-community/#!/grippers:marker-holder

See also:

• Current Tool Interface CAD files (note: this will be replaced): OnShape, STL There is room in the body for wiring and a Tinyduino interface device which can be attached with slightly longer bolts.
• http://hdrobotic.com/dexter-community/#!/grippers Our forum section for grippers.
• https://www.eng.yale.edu/grablab/openhand/ These are good designs for open source grippers. They do NOT have the exact tool interface for Dexter, but could be adapted, or the tool interface part can be replace.