What is the sense of a RTOS on a single-chip microcontroller?

Question

Hello,I do not have a idea, where a RTOS on a singlechip microcontroller isgood for. I know, that it is good for making two (or more) processesparallel but cannot imagine, how this works. O.K, a simple example tomake it clear. There is microcontroller and two processes shall run onit. The first one ANDs two intput-pins and gives the result to anoutput-pin. The second one ORs two other inputs and gives the resultto another output-pin. If I want to make this processes parallel Iwrite both commands into one program and they will run "parallel".What would be the way, the RTOS would make this two processes"parallel"?

DJ Delorie · Accepted Answer

Consider my furnace project. Each MCU is constantly running a 1wire search to check for buttons, scanning a 1wire temperature and humidity module, talking to the gumstix via i2c, queuing up serial data for the LCD, keeping track of the time, and keeping some LEDs updated.

Or look at something like eCos, which includes interrupt-driven device drivers for serial, USB, ethernet, etc, and includes a full TCP/IP stack and file system drivers for everything from flash to hard drives.

The two "processes" don't have to both be applications. You can have one application (the "main" thread) and lots of threads taking care of your devices.

And RTOS also provides a number of standard services, like networking, serial channels (rs232, usb, SPI), file systems, etc.

FreeRTOS.org · Answer

Here are some ideas, although it is really very dependent on the characteristics of your application.-- Regards,Richard.+  official architecture ports, 1000 downloads per week.+  by TÜV as meeting the requirements for safety related systems.

Paul Rosen · Answer

Thanks, very good. That answers indeed, what I was not able to ask.:-) A further question: Are there URLs, a forum or a group concerningFreeRTOS on the Microchip dsPIC signalcontrollers?

FreeRTOS.org · Answer

Specific to  in general, rather than just the dsPIC: -- Regards,Richard.+  official architecture ports, 1000 downloads per week.+  by TÜV as meeting the requirements for safety related systems.

Archi · Answer

OT: DJ, I am still using your wanderful GCC port for DOS (lot ofthanks for it). I never had any idea your intrests are so wide!Thanks,Arcady

What is the sense of a RTOS on a single-chip microcontroller?

Join the Discussion

Didn't find your answer?