RTOS for PIC18 microcontrollers

To eliminate busy waiting as much as possible, handle several tasks of different computation length and increase interrupt latency, using a RTOS (Real Time Operating System) on a microcontroller is efficient and effective. Although several RTOS´s are available for PIC microcontrollers most of them are not provided free and expensive and rarely available for PIC18 devices. This paper describes a compact and efficient RTOS for PIC18 devices. This RTOS includes Preemptive multitasking, voluntary yield, Dynamic memory allocation, Inter thread communication, and Drivers for hardware which minimizes busy waiting and achieves optimum performance. The design has good performance, smaller code size and low memory usage as the design was specifically implemented for PIC18 devices.