我在为我的状态机使用 case 语句数组时遇到问题。大多数网站都提到数组不能用于 case 语句，所以我一直在尝试解决它，但到目前为止还没有成功。我真的很感激任何帮助或建议。 澄清:我不想对状态进行硬编码，我试图以这样的方式制作程序，即如果用户仅更改 fsm_state_array[] 中的顺序，程序将以该方式执行仅排序而不更改 void loop() 中的任何其他内容。
这是我到目前为止尝试过的方法，当用户在数组中输入他们的状态序列时，我使用硬编码函数来检查先前状态、当前状态和下一个状态，所以在我下面的代码中状态应该去从 0 --> 2 --> 3--> 1，但是，我得到 0 --> 2 --> 1 --> 3。我知道如果我只在案例中使用数组，这个问题可以很容易地解决声明，但编译器给我一个错误。我非常感谢对此的任何帮助或建议。
我的代码如下所示:
//Objectives: Use input from laser to control pre-amp on adc. Multiplex the inputs on Pre-Amp
//Type: Pulse, Freq:20Hz (50ms), Amp:5.0 Vpp, Offset:500mV, Width = 100ns
//-----------------------PROJECT LIBRARIES----------------------------------
#include <Bounce2.h>
#include <Arduino.h>
#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/interrupt.h>
//-----------------------DEFINES------------------------------------------
//Declare Laser Input Pin
#define LASER_PIN 2
//Declare Reset Pin
#define RESET_PIN 3
typedef enum {
STATE_0,
STATE_1,
STATE_2,
STATE_3
} fsm_state;
//User can change or remove states here
fsm_state fsm_state_Array[] = {STATE_0, STATE_2, STATE_3, STATE_1};
//*eNextstate controls on which state the program starts the state machine, default is STATE_00, Must be same value as Transition_State[0]
fsm_state eNextState = fsm_state_Array[0];
int Current_State = 0;
int Next_State = 0;
int Previous_State = 0;
// -------------------------CONSTANTS (won't change)-------------------------------------
const unsigned long period = 1000; //the value is a number of milliseconds
//-------------------------VARIABLES (will change)-------------------------------------
bool only_for_print = false;//used only for print state ments
int reset_switch = 1;//Start HIGH to avoid reset
int PulseCount = 0; //Pulse count from X-RAY
int Output = 0;//Switch state on the Pre-Amp
int wait = 0;//wait for pulses count
int N = 20;//no. of pulses to count before switching states
volatile int IRQcount = 0;
volatile boolean reset_flag = false;
unsigned long start_time = 0;
unsigned long current_time = 0;
//----------------------------USER DEFINED FUNCTIONS---------------------------------
void fsm();
void loop();
void setup();
void WDT_RESET();
void IRQcounter();
void CountPulses();
//-----------------------------DEBOUNCE FUNCTIONS---------------------------------------
//--------------------------------MAIN SETUP--------------------------------------
void setup()
{
Serial.begin(115200);
//Pin Setup
pinMode(LASER_PIN, INPUT_PULLUP);
pinMode(RESET_PIN, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(LASER_PIN), IRQcounter, RISING);//attach interrupt handler to laser input
attachInterrupt (digitalPinToInterrupt (RESET_PIN), RESET_ISR, FALLING); // attach interrupt handler to reset, wait for user press button or switch
start_time = millis(); //initial start time
sei();//Turn on Interrupts
WaitForPulses();//Waits to detect 20 pulses
}
//--------------------------------MAIN LOOP----------------------------------
void loop()
{
current_time = millis();
fsm();//State machine
}
//--------------------------------PULSE COUNT FUNCTION--------------------------------------------
void CountPulses()
{
// current_time = millis();
if ((current_time - start_time) >= period)
{
start_time = current_time;
cli();//disable interrupts
PulseCount = IRQcount;
IRQcount = 0;
Serial.print(F("Pulse Count is = "));
Serial.println(PulseCount);
sei();//enable interrupts
}
}
//--------------------------------STATE MACHINE FUNCTION--------------------------------------------
void fsm()
{
switch (eNextState)
{
case STATE_0:
/////////Print Statement only for debugging//////////
while (only_for_print == false)
{
Serial.println("The state is 0");
only_for_print = true;
}
///////// Count Pulses Setup /////////////////
Previous_State = fsm_state_Array[3];
Current_State= 0;
Next_State = fsm_state_Array[1];
current_time = millis();
CountPulses();
Output = 0;
if (PulseCount == N)
{
PulseCount = 0;//Reset Pulse Count
only_for_print = false; //used only for print statments
State_Check_0_to_1();//Move to next state
}
break;
case STATE_1:
/////////Print Statement only for debugging//////////
while (only_for_print == false)
{
Serial.println("The state is 1");
only_for_print = true;
}
///////// Count Pulses Setup /////////////////
Previous_State = fsm_state_Array[0];
Current_State= 1;
Next_State = fsm_state_Array[2];
current_time = millis();
CountPulses();
Output = 1;
if (PulseCount == N)
{
PulseCount = 0;//Reset Pulse Count
only_for_print = false; //used only for print statments
State_Check_1_to_2();//Move to next state
}
break;
case STATE_2:
/////////Print Statement only for debugging//////////
while (only_for_print == false)
{
Serial.println("The state is 2");
only_for_print = true;
}
///////// Count Pulses Setup /////////////////
Previous_State = fsm_state_Array[1];
Current_State= 2;
Next_State = fsm_state_Array[3];
current_time = millis();
CountPulses();
Output = 2;
if (PulseCount == N)
{
PulseCount = 0;//Reset Pulse Count
only_for_print = false; //used only for print statments
State_Check_2_to_3();//Move to next state
}
break;
case STATE_3:
/////////Print Statement only for debugging//////////
while (only_for_print == false)
{
Serial.println("The state is 3");
only_for_print = true;
}
///////// Count Pulses Setup /////////////////
Previous_State = fsm_state_Array[2];
Current_State= 3;
Next_State = fsm_state_Array[0];
current_time = millis();
CountPulses();
Output = 3;
if (PulseCount == N)
{
PulseCount = 0;//Reset Pulse Count
only_for_print = false; //used only for print statments
State_Check_3_to_0();//Move to next state
}
break;
}
}
//----------------------------------RESET SWITCH ISR-------------------------------------
void RESET_ISR()
{
reset_flag = true;
if (reset_flag == true)
{
// Serial.println("System will now Reset");// Only for debugging
reset_flag = false;//Reset reset switch flag
wdt_enable(WDTO_500MS);//Reset after 0.5 seconds
while (1)
{
// wdt_reset(); // uncomment to avoid reboot
}
}
}
//-----------------------PULSE COUNT ISR---------------------------------------
void IRQcounter()
{
IRQcount++;
}
//-----------------------WAIT FOR PULSES---------------------------------------
void WaitForPulses()
{
while (wait < 20)
{
if (bit_is_set(EIFR, INTF0))
{
Serial.println("Pulse is detected ");
wait++;
}
}
wait = 0;//reset
}
void State_Check_0_to_1()//Check values of state 0 before going to state 1
{
if(Previous_State == fsm_state_Array[3] && Current_State == 0 && Next_State == fsm_state_Array[1])
{
eNextState = Next_State;
}
}
void State_Check_1_to_2()//Check values of state 1 before going to state 2
{
if((Previous_State == fsm_state_Array[0]) && (Current_State == 1) && (Next_State == fsm_state_Array[2]))
{
eNextState = Next_State;
}
}
void State_Check_2_to_3()//Check values of state 2 before going to state 3
{
if((Previous_State == fsm_state_Array[1]) && (Current_State == 2) && (Next_State == fsm_state_Array[3]))
{
eNextState = Next_State;
}
}
void State_Check_3_to_0()//Check values of state 3 before going to state 0
{
if((Previous_State == fsm_state_Array[2]) && (Current_State == 3) && (Next_State == fsm_state_Array[0]))
{
eNextState = Next_State;
}
}
这是我的串行监视器显示的内容:
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
Pulse is detected
The state is 0 -----> State 0
Pulse Count is = 72
Pulse Count is = 19
Pulse Count is = 20
The state is 2 -----> State 2
Pulse Count is = 20
The state is 1 -----> State 1
Pulse Count is = 21
Pulse Count is = 19
Pulse Count is = 21
Pulse Count is = 19
Pulse Count is = 21
Pulse Count is = 19
Pulse Count is = 21
Pulse Count is = 19
Pulse Count is = 21
Pulse Count is = 20
The state is 3 -----> State 3
Pulse Count is = 20
The state is 0
Pulse Count is = 20
The state is 2
Pulse Count is = 20
The state is 1
Pulse Count is = 20
The state is 3
按照评论中的建议，使用指针测试 FSM 的单独代码:
typedef void (*current_state)();
void state0();
void state1();
void state2();
void state3();
current_state states[4]={&state0,&state2,&state3,&state1};
current_state next_state;
void setup()
{
Serial.begin(115200);
}
void loop()
{
current_state();
}
void state0()
{
next_state = states[1]; // No parenthesis!
Serial.println("I am in STATE 0");
}
void state1()
{
next_state = states[2]; // No parenthesis!
Serial.println("I am in STATE 1");
}
void state2()
{
next_state = states[3]; // No parenthesis!
Serial.println("I am in STATE 2");
}
void state3()
{
next_state = states[0]; // No parenthesis!
Serial.println("I am in STATE 3");
}
最佳答案
此代码来自 STATE_2 的处理
Next_State = fsm_state_Array[3];
将 Next_State 设置为 STATE_1 因为数组初始化为
fsm_state fsm_state_Array[] = {STATE_0, STATE_2, STATE_3, STATE_1};
这意味着...
fsm_state_Array[0] = STATE_0;
fsm_state_Array[1] = STATE_2;
fsm_state_Array[2] = STATE_3;
fsm_state_Array[3] = STATE_1; // This is the element used
为了提供一个更“动态”的解决方案，可能对状态使用函数指针比使用开关效果更好:
// Current state is just a apointer to a void function
// accepting no parameters
void (*current_state)();
// All states are just void functions accepting no parameters
void state1();
void state2();
...
// To set what is the next state you update current_state
void state1() {
...
current_state = state2; // No parenthesis!
}
// In the main handler you just call current_state
...
current_state(); // Do the state processing
如果你想执行一系列操作然后使用函数指针你可以只保留一个数组并迭代它:
void (*states[])() = {
state1,
state2,
state3,
...
NULL /// To mark the end of the sequence
};
然后你可以按顺序执行这些步骤
void main() {
for(int i=0; states[i]; i++) {
states[i](); // Execute the step
}
}
关于c++ - Case 语句中的数组，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/58720331/