Testing CAN for Robotic Control

Hany Ferdinando

Research output: Book/ReportReportOther research output


This project elaborates link drivers for the ADSP-21992. They are link drivers for Analog to Digital Converter (ADC), Encoder Interface Unit (EIU), Auxiliary PWM and the Control Area Network (CAN) bus. All link drivers are derived from the abstract LinkDriver class available in the CT Library. These link drivers are applied to a DC motor speed control with the PID Controller. This project will use two ADSP-21992 EZ-KIT LITE boards (evaluation board). There are two configurations, i.e. one-way and two-way configurations. For the one-way configuration, board 1 reads reference signal (from ADCLinkDriver) and actual speed (from EIULinkDriver) then send the difference between those two to board 2 via CAN bus (CANLinkDriver). Before sending this data to board 2, board 1 send synchronization pulse to board 2 to write PWM value. Upon receiving this data, board 2 calculates the PID Controller output, then wait for synchronization pulse from board 1. There is only one communication between two boards. For the two-way configuration, board 1 reads value from ADC and encoder, actuates the PWM by writing PWM value and sends the difference between reference signal and actual speed as in one-way configuration. The process on board 2 is almost the same as in the one-way configuration, except the result is not written to PWM but to CAN bus. The main issue is the highest sampling frequency for each configuration. The sampling frequency also depends on the CAN speed. Therefore, this is presented based on the CAN speed. From the experiment, it can be concluded that sampling frequency depends on the CAN speed. The relationship between CAN speed and sampling frequency is not linear. This is due to the fact that reading data from ADC and EIU (encoder) do not depend on CAN speed.
Original languageUndefined
Publication statusPublished - 2004
Externally publishedYes


  • IR-56342

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