The RH4D exposes multiple interfaces and protocol options, such as the Seed Robotics STP protocol and the Dynamixel Protocol.
This document assumes you are familiar with the Dynamixel Protocol.

The RH4D, like all Seed Robotics products, can be connected directly to any chain of Dynamixel devices. It is compatible with TTL and RS485 devices (depending on your choice of model) and supports the Dynamixel 1.0 and 2.0 protocol.
It will operate on the bus like any other Dynamixel device, exposing its IDs and Memory Table.

The RH4D ships configured with the following defaults:

By default the unit ships configured for operation at 1Mbps (8 data bits, no parity, 1 stop bit like all Dynamixel devices) on the External communications port (the one at the back of the hand).

It is possible to change the communication speed from 9600bps up to 3Mbps. We recommend operating at 1Mbps.

The RH4D exposes 5 IDs on the bus:

  • 1 I D for the main control board where you can query the high-level functionality of the system as well as get all real-time current measurements at once.
  • 4 I Ds for the actuators: each actuator has its own I D and Control table, for direct control and individual tuning of PID, zero offset and other parameters.

For ease of use, we pre configure the IDs on each unit. Furthermore, each I D is connected to a main board port that is directly related to the I D number. To get the board port, take the last digit of the I D and subtract it by 1.

For example, for I D 24, take the last digit - 4 - and subtract 1, becoming 3. This I D is connected to the main board port 3, where you will be able to find the current reading and other parameters that are externally measured for the unit.

The default I Ds can be changed to suit the user needs. However, for ease of use, we recommend keeping some form of relation between the ID number and the port number on the board.

Default I Ds for the Left Hand

  • 22 Main board
  • 24 Wrist Rotation
  • 26 Wrist Flexion
  • 28 Thumb finger flexion
  • 30 Index finders flextion

Default I Ds for the Right Hand

  • 21 Main board
  • 23 Wrist Rotation
  • 25 Wrist Flexion
  • 27 Thumb finger flexion
  • 29 Index finders flextion

The SR-RH4D is symmetrical in terms of mechanical design; therefore, even though they may come programmed with Left hand or Right hand IDs, they can be used in the symmetrical position. You may want to adjust the IDs accordingly though.

For further information on controlling the unit, please consult the RH4D Control Tables.

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  • rh4d/dynamixelidsandcommsettings.txt
  • Last modified: 2018/02/19 11:10
  • by Pedro Ramilo