Software Troubleshooting

This page is designed to help with the most common issues with your DH4D hand. If you experience any issues not covered here or would like a personalized assistance, we'll be more than happy to be of help at support@seedorbotics.com

Hand is not communicating over the Dynamixel Interface

Ensure the unit is powered and booted properly

First, make sure the unit is being powered through external power applied (at least 8V) to the main interface port (the one on the back of the hand). Powering via USB will turn on the main board but will not power any of the subsystems such as the actuators.

On power up, the hand LED becomes bright white (or a solid colour, if you an EROS Architecture) during initialization and after a couple of seconds turns to a dimmer white.
If your unit is not exhibiting this behaviour during boot, we suggest re installing the firmware. If the problem persists, please get in touch with Seed Robotics support. There are a few more steps you can do have the eeprom settings reset.

Check for any errors reported by a blinking LED

If, upon power up, the LED begins blinking, please check the LED Error codes. This is a self diagnostic feature that will let you know exactly what is happening with your unit. You may get in touch with our Support Team if you need help understanding or overcoming any of the errors.

Check the Dynamixel Communication Settings

Lack of communication of often caused by incorrect setting of the Baud Rate, Return Delay Time of Status Return level.
Incorrect IDs can also cause this but are usually easier to diagnose.

To diagnose the Dynamixel settings you need to connect to the hand over USB. After connecting via USB, please enter the following console command: did (for Aries Architecture) or status for Eros Architecture
(if the command returns no reply, make sure your Serial Terminal has the Line Ending set to CR LF)

On the reply you get, check the following:

  • Baud Rate: make sure it is set to the same Baud Rate at which your system is operating. (factory default is 1Mbps).
  • Status Return Level: should be set to 2 (which means “always return”). If it is set to a lower number the unit may not return a reply on certain conditions (see the Robotis Dynamixel documentation to understand this parameter).
  • Return Delay Time: this should be set somewhere between 0~250 (meaning between 0 and 500 micro seconds).

IMPORTANT: there is a firmware implementation error for the Return Delay Time in firmware versions ⇐9. This is known to cause issues as the hand interprets the parameter as return timeout.
We encourage users to upgrade to version 10 or newer. If you do not wish to upgrade, as a work around, leave the parameter at 250 which will keep the unit responsive, and responding as fast as possible.

Ares Only:
If your Dynamixel Communication settings are incorrect and you would like to return them to defaults, enter the command ree 1 in the USB or Bluetooth Console. This will reset the Baud Rate, Return Delay Time and Status Return Level to factory defaults: 1Mbps, 250(500microsecs), 2(always return).

Finally, if you have incorrect I Ds and need to change them, please follow the normal procedure to change Dynamixel I D's. The best practice, if you have overlapping I D's on the bus, is to disconnect all devices and connect only the Hand when performing the I D change procedure.

Hand is not communicating over the USB Interface

Check that the device is recognized by the Host computer

The USB interface exposes a Virtual COMM port to the operating system.

The first thing to check is if your O/S is recognizing the device once it's connected. In Windows you can do this in Device Manager. In Linux it should be listed under /dev. Linux and Mac should not require any special drivers. However, for certain versions of Windows you may need to install the Drivers for the Serial port. See the USB console instructions.

Check the Line Ending on your Serial Terminal program

Every console command must be terminated by CR+LF in order to be parsed by the hand. Serial Terminal software packages, usually have an option to define the characters for line ending. Make sure they are set to CR+LF.

Hand is not communicating over the Bluetooth Interface or I simply can't find it when scanning

Confirm that your hand was equipped with the Bluetooth module

The Bluetooth interface is an optional component, which is fitted on customer request. Therefore not all hands will have this option.
To check if your Bluetooth module is installed, connect to your Hand over USB and enter the command bti (Ares Architecture) or status (Eros Architecture).
It will tell you whether the module is Not Present or, if present, what are the connection settings (including broadcast name and Pairing code). If you are absolutely sure your hand was fitted with a Bluetooth module, and the above command tells you otherwise, then please get in touch with our support team for additional troubleshooting.

Check your Broadcast name, Pairing code and the Power status of module

For this step, you will need to connect to your Hand over USB and enter the command bti (Ares Architecture) or status (Eros Architecture).

The output will tell you:

  • Your hand broadcast name. (by default 'SEED_[S/N]')
  • The pairing code (by default '1234', but this is user changeable to please double check it)
  • The Power Status of the module. This is particularly important because it is possible to turn the module OFF through the Control Table of the Virtual I D / Main Board.

If the unit shows the module is powered off, you can re enable it through the control tables. Alternatively if you power cycle the whole unit, when it comes back up, the module should be powered up again (this is the default behavior)

Check the Line Ending on your Serial Terminal program

Every console command must be terminated by CR LF in order to be parsed by the hand. Serial Terminal software packages, usually have an option to define the characters for line ending. Make sure they are set to CR LF.

Please get in touch with our support team at support@seedrobotics.com

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  • dh4d/softwaretroubleshooting.txt
  • Last modified: 2017/03/23 12:20
  • by wadmin