Originally the Pioneer Robot was purchased by Murdoch University with an on-board Linux based personal computer to facilitate teaching Software Engineering. As Murdoch’s Software Engineering program has since been abandoned, the computer has been replaced with microcontrollers to facilitate Industrial Computer Systems Engineering teachings. Given that existing industrial networking protocols often require large memory allocations and significant processing power, this thesis looks at building a protocol to connect these multiple microcontrollers that uses less processing and memory requirements. Another key requirement is the ability to report exceptional events outside routine polling undertaken by the communications master.
The outcome was the development of a new master-slave protocol over an RS-485 physical layer using an New Micros NMIS 5000 board and an Arduino shield built using a National Semiconductors DS75176BN integrated circuit. The protocol was implemented within a prototype system using personal computers connected by Alfatron RS-232 to RS-485 interface converters. State machine program design was used to develop the prototype protocol in the National Instruments Labview environment. Data collision issues were overcome using a scheduling approach to refine the ‘free bus’ idea for exceptional event reporting. Although the final prototype would benefit from further refinement, it is advanced enough to be implemented in a functioning network.