Proceedings of International Conference on Computational Methods in Engineering and Health Sciences, December 17-19, 2014. Directorate of Research, Manipal University ES013- 01 Abstract—This paper considers a computation method for accepting data about the present status of a motor, and then controlling it to move in a specific direction, up to a specific limit using the CANopen communication protocol. The investigation is focused on developing a reliable algorithm for controlling such motors in a CANopen network with multiple nodes (based on the BioBike project being carried out at Hochschule Ulm, Germany). PIC microcontrollers are used to communicate over the CAN bus-network, along with a Bluetooth interface to communicate with a control program on a remote computer. The major considerations in coding the embedded programs for such communication are explained. Special attention is paid to the management of data traffic and to improving the response of various nodes over the network. Keywords—: BioBike, CANopen, data traffic, motor position control. I. INTRODUCTION HE growing trend of integrating multiple independently manufactured electronics components into a single compact system has given rise to the idea of standardization of communication protocols. Such standards enable the addition of newer components or „nodes‟ to the system over time, allowing continuity in any ongoing project or research. The BioBike (Fig. 1) project being developed at Hochschule Ulm, University of Applied Sciences, Germany, aims to develop a special test bench for bikers covering biomechanics, effective pedaling, and optimal power consumption. The project extracts the optimal position between the biker‟s seat, the handlebars, and the pedals in order to produce maximum forces through minimum effort by the biker. Vedant Prusty is an undergraduate Student pursuing a Bachelor‟s degree at the Dept. of Mechatronics, in Manipal Institute of Technology, Manipal, India 576104. This paper is based on his work at Hochschule Ulm – University of Applied Sciences, Ulm, Germany, where he worked at the Laboratory for Medical Technology in the Department of Mechatronics and Medical Engineering. (e-mail: vedant.prusty@learner.manipal.edu). The BioBike has four DC motors, controlling the Seat and Handlebar positions, forwards-backwards and up- down. The seat and the handlebar have four potentiometers attached to them. These potentiometers send back values as voltages, which is interpreted by the microcontroller as the present position of the seat and handlebar. Simple DC motor control using microcontrollers is being researched upon even today [1]. However, the complexity presented through multiple nodes and various types of devices in the BioBike require that a dedicated and fast communication protocol be used. Fig. 1 Control Plan of the BioBike System being designed at Hochschule Ulm II. COMMUNICATION WITH CANOPEN PROTOCOL A. CAN-bus The CAN (Controller Area Network) bus is a serial bus that works with a differential tension. Each CAN node is connected in parallel. (Two termination resistors of 120 Ohm at the ends of the bus are recommended. [2]) Here, a node represents any device following the same Implementing the CANopen protocol in a Multiple Node System in the BioBike for Motor Position Control Vedant Prusty T