Previous examples illustrated VELOOS programming aspects. This post provides an example of using object oriented paradigm for designing VELOOS application. Unlike the previous examples which were purely programming exercises, this example is dedicated to a utilitarian home appliance application and provides a "reference design" for VELOOS applications.
This example for PIC12F675 implements set of “actuators” and “generators” controlled via USART. Actuators produce one 300 ms pulse when it receives command ‘ON’ and three 100 ms pulses delimited with 100 ms spaces (pauses) on command ‘OFF’. Generators, when turned on, produce pulses and spaces of the specified duration (1..255).
VELOOS is an object-oriented message-triggered cooperative operating system for 8-bit Microchip microcontrollers licensed to public under the Open Software License
Release 1.0 includes VELOOS kernel and two timer drivers (TMR0 and TMR2 based). It has been tested on the following devices: PIC12F675, PIC16F690, PIC18F248.
This post continues series of examples and describes how VELOOS can be used for implementing time-triggered applications.
The previous post gave a brief introduction to VELOOS design idea. VELOOS assumes that an application is decomposed on PDOs (Process Data Objects). This post describes by example features provided by VELOOS for implementing PDO.
VELOOS - Very Low Overhead Operating System
VELOOS is a message-triggered cooperative operating system designed to run in places were a large vehicles can not run. Its implementation for PIC12F takes less than 200 instructions and 20 data registers1. With addition of a timer driver, it becomes a time-triggered RTOS.