Author: Norberto Torres-Reyes Email: torresre@unlv.nevada.edu
Date: Last modified on 04/23/19
Keywords: kinematics, planar, robotic arm, 2 link, lego, NXC, NXT, mindstorm, dynamixel, plotting

This tutorial is for anyone who wishes to create a 2-link plotting robotic arm using LEGO Mindstorm, NXC software, and Dynamixel RX-28 servos. This tutorial will also reinforce theoretical knowledge about 2-link planar mechanisms, serial communication, and servo control. Readers of this tutorial are recommended to have the following background and interests:

*Previous experience with LEGO Mindstorm
*Matlab and/or C-based programming experience
*Knowledge of linear algebra
*Some knowledge in serial communcation
*Experience with using servos

The rest of the tutorial is presented as follows:

• Parts List
• Theoretical Background
• Build Plans
• NXC Code
• Running, Testing and Analysis
• Conclusions

A few parts for controlling the Dynamixels will be needed along with some parts used to communicate between the NXT Brick and the Dynamixel. The LEGO parts list is shown in the Build Plans section.

Dynamixel RX28
https://www.trossenrobotics.com/dynamixel-rx-28-robot-actuator.aspx

Lego BreadBoard Adapter
http://www.mindsensors.com/ev3-and-nxt/58-breadboard-connector-kit-for-nxt-or-ev3

SMPS2Dynamixel
http://www.robotis.us/smps2dynamixel/

(Optional) HiLetgo USB Logic Analyzer
https://www.amazon.com/gp/product/B077LSG5P2/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1


Other Parts Needed:

• NXT Cable

• Dynamixel Connector Cables

• USB A-to-C cable

• 12V 2-Amp Power Supply