Delta robot is a 3-axis parallel manipulator. It has a unique kinematic design that allows it to perform translation without changing its orientation. In addition, all the three motors are placed stationary on the ground making it able to move faster because it does not have to carry around the weight of the motor. The mechanical design and the forward and inverse kinematics was completed by an undergraduate student, Mr. Sikarin, at Mahidol University. This delta robot prototype was built in 2005. All of the robot's motion controller is designed and made in-house. Each motor is controlled by the DC motor controller, which is implemented on PIC microcontroller 18F2331. It decodes the motor's quadrature signal into a position count, and generates motor PWM command according to a PD control scheme. The main controller, implemented on a PIC microcontroller 18F458 serves as an I2C master to communicate with the three PIC18F2331 (I2C slaves) and with a PC through RS232 protocol. The motor driver uses four MOSFETs IRFZ44N to form a H-Bridge configuration. The MOSFET is controlled using an H-Bridge controller HIP4080. The driver takes the following inputs: (1) PWM, (2) direction, and (3) ground reference. The control inputs are isolated from the power by an opto isolator, which allows the circuit to have separate power and control grounds. The robot can be controlled by a PC via its serial port (RS232). The user can use HyperTerminal or Matlab to control the robot position. With HyperTerminal, the user can read the robot's joint positions in encoder counts and send out desired positions to the robot. With Matlab, in addition to reading and writing joint positions like in HyperTerminal, the user can also compute inverse kinematics in order to control the robot in Cartesian coordinates.Circuit Schematic Diagrams