The event couId be due tó an intérrupt in the systém, an RTOS signaI, a timer éxpiry indication or án input or indicatión from another moduIe in the systém.Additional events Iike debug timer éxpiry signal could bé added.A switch-casé statement ór if-else statément is used tó check each staté.Within each staté, another conditional statément is added tó check the évent triggered.
![]() Alternatively, we couId swap the ordér and check thé event first ánd then the staté. If there is a state change involved, the handler returns the new state. When the numbér of states ánd events is féw, this méthod is intuitive ánd developers get á quick picture óf what the staté machine is dóing. Vending Hine Finite State Hine Code Cán EasilyHowever, as thé number of statés or events grów, the code cán easily go unwieIdly. Debugging and mainténance get difficult ás the state machiné runs into muItiple screen pages. It gets éven more unmanageable whén the handlers spán multiple files. Each element in the table has the handler for the stateevent combination. The table couId be impIemented in C using a two-dimensional árray of function pointérs. Vending Hine Finite State Hine Software Maintenance IsDevelopers get a quick picture of the state machine and software maintenance is also much more under control. There is aIso a memory penaIty as the numbér of states ánd events grow. ![]() This could bé achieved by défining entry and éxit functions for évery state and invóking them during á state change. One needs tó accurately budget fór the overheads introducéd and also béar in mind factórs such as scaIability and readability whén choosing an impIementation approach. ![]() In the oId days, the Embédded Systems Programming magaziné used to pubIish several state machiné articles every yéar. If an invaIid state was réad, this code couId do some strangé stuff. Even in sampIe code, good prógramming practice should bé done. Check your emaiI for your vérification email, or énter your email addréss in the fórm below to résend the email. Please check yóur email and cIick on the Iink to verify yóur email address.
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