What is Real Time Operating System(RTOS) ?
Operating System must have heard this name earlier but only in relation to Windows, Linux, and MAC OS which are there in Laptops and Computer devices. Most people are aware of only these Operating Systems in general terms which are there in most the General Purpose Computers. But what if I told you that there is an Operating System in most of the electronic devices (Embedded devices) around us like Earphones, Setup Boxes, Cars, speakers, Air Conditioners, Smart Watches, Medical devices and etc?
Operating System is basically a software stack that allows the Electronic/Electrical devices to mimic the sensing of multiple inputs, their processing and correspondingly controlling multiple outputs at an instantaneous time.
All of these Embedded devices have multiple inputs that need to be sensed, then processed, and correspondingly control the outputs. All of this happens in a real-time and mimic to happen at an instantaneous time. These Embedded devices work in Real-time data on time-critical and small memory space constraints.
To put it in a different perspective, imagine a manned spacecraft in low earth orbit traveling about 17,000 miles an hour. Suppose that every 1,000 seconds, it has to fire an orbital maneuvering system rocket for 3.8 seconds to avoid deorbit. A one-second unit of time translates to 25,000 feet of distance covered. Imagine what nightmare would ensue if the spacecraft avionics had to stop, wait for the navigation system to page back in, fire the rockets, and then wait for the next interruption to stop firing the rockets. It could take five seconds or more. In that time the spacecraft will deviate 25 miles from its projected course.
You can take any example, let\’s say of speakers. Speakers are connected to our phones for playing music, the moment when we press a song to be played at just a fraction of sec that music gets start playing. But have you ever thought that what all process is behind this? There is Bluetooth signal that has to be send from our phone to speakers, then speakers process and compute the signal that it receives. Then according to signal, speaker base start vibrating to play the music. The connection between phone and speakers should be continuous, so that signal to play the music (lyrics basically) is not interrupted. If in between to this we need to lower the volume or change the BASS of music those signals also have to be processes, computed and executed. Same way out you can try to think the flow of working of electronic devices around you and realize that Operating System is everywhere not just in our desktops.
Operating system used in Embedded devices is called Real Time Operating System (RTOS). RTOS is very important topic and concept to be understood to make complex electronics/electrical application projects which are time critical like nuclear monitoring devices, Anti-brake system, automotive ECU\’s, Programmable logic Controllers (PLC\’s), Automated guided vehicle\’s (AGV), Motor drivers which are there in metros/airplanes/vehicles, and many such examples (In some cases, instead of RTOS, Linux OS is also used. That is different topic to be touched).
Author: Kunal Gupta
