Microcontrollers are highly integrated computer systems on a chip:a processor and various support functions such as program memory,discrete I/O, A/D converters, serial communications, counter/timers,and watchdog timers are normally integrated in the same chip.
They are the key component for software-based data acquisition and simple controlling applications giving a higher flexibility and autonomous capability versus pure hardware solutions. They are widely used in many spacecraft subsystems and applications such as:
- propulsion system control
- sensor bus control
- robotics applications
- simple motors control
- mechanisms control
- power control
- radiation environment monitors
- thermal control
- antenna pointing control
- AOCS/GNC sensors (Gyro, IMU, MTM)
- RTU control
For this type of applications, where limited performances are requested of the processor, general purpose microprocessors are usually considered inadequate for the tasks due to high power consumption, high pin count packages, an the need of external memories and peripherals. Low-end microcontrollers are therefore considered a more attractive solution.
The following block diagram is an example of Microcontroller for space applications; It is a SPARC based microcontroller derived from a reduced version of the LEON2-FT processor core.