EXTRACTED FROM THE PDF FILE DESCRIBING OPEX
beta 1. Testing to date with demo program is reliable with long run times.
OPEX Is …
C software for WinAVR (GCC) optionally using the Atman IDE
For an embedded system (microprocessor) programmer who is using the C language.
A control program
To oversee multiple “thread-like” processes. Each process or “task” uses only ~22 bytes of overhead
To cause processes to run when desired, such as:·
At specific dates and/or times, optionally recurring·
At time intervals, either fixed or variable, optionally recurring·;
When the serial port receives a byte or an end-of-line character·;
When inter-process signals are received
An Easy Way To Implement Multiple State Machines
Using the Scheduler’s functions which include, among others·
Task Create and Quit·
Task time delay or wait for specific date/time·
Task wait-for-flag, set-flag (semaphore)
A clock and calendar
With time zone, daylight savings and leap year, maintained using a microprocessor timer such as the 32768KHz asynchronous oscillator of the Atmel megas.
Serial port support
Functions for interrupt driven input/output, optionally non-blocking, for binary or string (ASCII 8 bit) data
Monitoring and Debugging Aids
Functions to format and display a list of all processes, the detailed state and status of each, plus RAM used and unused, and maximum observed stack depth
Automatic Memory Allocation Housekeeping A task may use the OPEX forms of malloc() to obtain temporary use of a block of RAM. When the task quits, OPEX automatically frees this memory if the task did not do so. A modified version of the standard malloc() is included in OPEX.
Complete with Examples
Dallas 1-wire reader for DS1820 temperature chips
I/O bit sensing and switch debouncingSerial I/O for host commands
and set clock/calendar