Arduino陣列中的損壞值

Question

該程序應該不斷收聽來自花盆中土壤濕度傳感器的433 MHz消息，並根據這些讀數來決定是否激活泵。
另外，它應該在收聽時檢查有線水傳感器。

所有收到的433 MHz消息應存儲在數組sensor_data[i] 。
在啟動時，位置1到NUM_Sensors （在這種情況下為3）填充有常量int NO_DATA （500）。
問題是，由於某種原因，我損壞了陣列編號3中的數字：

串行打印：

Wired Flower Pots Checked
All Sensors or Timeout reached
Array_Print: 500
Array_Print: 500
Array_Print: 30001

在這種情況下，30001出現在陣列中沒有特定原因（我想）。.沒有收到消息。
這是更改為最少的代碼，以便發生錯誤：

#include <RCSwitch.h>
RCSwitch mySwitch = RCSwitch();
//Receiver Setup for wireless soil moisture readings
unsigned long last_ground_check = 0;
const int NUM_SENSORS = 3;
const uint32_t SENSOR_TIMEOUT = 30000;
int sensor_data[NUM_SENSORS];
uint32_t last_message_time = 0;
uint32_t elapsed = 0;
float total_value = 0;
float real_value = 0;
int count = 0;
const int NO_DATA = 500;
boolean received = false;
//###################//
void setup()
{
    Serial.begin(9600);
    mySwitch.enableReceive(INT1); // Interrupt 2 = Pin 2
    delay(1500);
    Serial.println("<><><><><><><><><><><><>");
    Serial.println("          Start         ");
    Serial.println("<><><><><><><><><><><><>");
    for (int i = 0; i <= NUM_SENSORS; i++) {
        sensor_data[i] = NO_DATA;
    }
} // Setup END
void loop()
{
    if (received == false) {
        if (millis() - last_ground_check > 10000) {
            Serial.println("Checking Wired Flower Pot");
        }
        Serial.println("Wired Flower Pots Checked");
        last_ground_check = millis();
    }
    if (mySwitch.available()) { // Start whenever a 433 MHz Message is received
        received = true;
        double value = mySwitch.getReceivedValue();
        delay(1000);
        int sensor_id = 1;
        int sensor_value = 2;
        if (sensor_value >= 0 && sensor_value <= 100) {
            sensor_data[sensor_id] = sensor_value;
            last_message_time = millis();
            mySwitch.resetAvailable();
        }
    }
    byte sensors_reported = 0;
    for (int i = 0; i <= NUM_SENSORS; i++) {
        if (NO_DATA != sensor_data[i]) {
            sensors_reported += 1; // CODE Gets here because of corrupted Array Value although no message was received
        }
    }
    if (sensors_reported != 0) {
        uint32_t elapsed = millis() - last_message_time;
        if (NUM_SENSORS == sensors_reported || elapsed > SENSOR_TIMEOUT) {
            Serial.println("All Sensors or Timeout reached");

            for (int i = 1; i <= NUM_SENSORS; i++) {
                Serial.print("Array_Print: ");
                Serial.println(sensor_data[i]);
            }
            for (int i = 1; i <= NUM_SENSORS; i++) {
                if (sensor_data[i] < NO_DATA) {
                    count++;
                    total_value += sensor_data[i];
                }
            }

            real_value = total_value / count;
            Serial.print("Soil Moisture: ");
            Serial.println(real_value);
            if (real_value <= 20) {
                //Set Pump ON
            }
            for (int i = 1; i <= NUM_SENSORS; i++) {
                sensor_data[i] = NO_DATA;
            }
            total_value = 0;
            real_value = 0;
            sensors_reported = 0;
            count = 0;
            received = false;
            Serial.println("RESET #### RESET ####");
            delay(5000);
        }
    }
} //LOOP

Answer 1

首先分配大小為NUM_SENSORS=3的數組，然后繼續使用它，就好像大小為4。

您的數組具有3個元素sensor_data[0] ， [1]和[2] 。 您的循環條件i <= NUM_SENSORS導致訪問sensor_data[3] ，這只是最后一個數組元素之后的一些內存。 即使在設置中設置了sensor_data[3] ，如果其他變量引用了相同的存儲器，則NO_DATA也將被覆蓋。

索引從i = 0到i < NUM_SENSORS的數據數組的循環。