User Tools

Site Tools


product:usb2ax:advanced_instructions

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
product:usb2ax:advanced_instructions [2014/02/25 00:47]
xevel
product:usb2ax:advanced_instructions [2018/04/02 22:16] (current)
xevel [SYNC_READ]
Line 55: Line 55:
 This allows for a significant performance boost when reading the same values in a lot of devices. This allows for a significant performance boost when reading the same values in a lot of devices.
  
-An implementation in the DynamxelSDK library is availalbe in the [[https://​github.com/​Xevel/​usb2ax/​tree/​master/​pc_software/​usb2ax_DynamixelSDK|GitHub repository]]+An (obsolete) ​implementation in the DynamxelSDK ​v1 library is availalbe in the [[https://​github.com/​Xevel/​usb2ax/​tree/​master/​pc_software/​usb2ax_DynamixelSDK|GitHub repository]]. The newer revisions of the Dynamixel SDK are not compatible with this definition of the SYNC_READ, which pre-dates the official one.
  
 **Warning: Various implementations of custom Dynamixel multiple-read commands named SYNC_READ can be found over the Internet, this one is based on the one found in the arbotix_python ROS package by Michael Ferguson. **Warning: Various implementations of custom Dynamixel multiple-read commands named SYNC_READ can be found over the Internet, this one is based on the one found in the arbotix_python ROS package by Michael Ferguson.
Line 73: Line 73:
   <​0xFF><​0xFF><​ID><​Length><​Instruction><​Param 1><​Param 2><​Param 3> ... <Param N+2><​Checksum>​   <​0xFF><​0xFF><​ID><​Length><​Instruction><​Param 1><​Param 2><​Param 3> ... <Param N+2><​Checksum>​
  
-  ID         : ​0XFD or 0xFE +  ID         : ​0xFD or 0xFE 
   Length ​    : N + 4 (N: number of Dynamixel actuators to read from, value between 1 and 32 inclusive) ​   Length ​    : N + 4 (N: number of Dynamixel actuators to read from, value between 1 and 32 inclusive) ​
-  Instruction: ​0X84+  Instruction: ​0x84
   Param 1    : Starting address of the location where the data is to be read from    Param 1    : Starting address of the location where the data is to be read from 
   Param 2    : L (L: length of the data to be read, value between 1 and 6 inclusive)   Param 2    : L (L: length of the data to be read, value between 1 and 6 inclusive)
Line 84: Line 84:
  
  
-**WARNING** Some choices of implementation of the Dynamixel SDK make it impossible to simply send this packet and expect a valid response. A modified version of the SDK will be availalbe to fix this problem.+**WARNING** Some choices of implementation of the Dynamixel SDK make it impossible to simply send this packet and expect a valid response.
  
  
product/usb2ax/advanced_instructions.1393285624.txt.gz · Last modified: 2014/02/25 00:47 by xevel