first commit

sound_meter/sound_meter_moving_avg.c

@@ -0,0 +1,122 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <linux/i2c-dev.h>
+#include <sys/ioctl.h>
+
+#define MAX_MEASURES 60  // To store 60 sound level measurements
+
+int main()
+{
+    int file;
+    char data;
+    int soundLevels[MAX_MEASURES];
+    int index = 0;
+    int sum = 0;
+    int i;
+    FILE *fileOutput;  // File pointer for writing to file
+
+
+    // Initialize the soundLevels array
+    for (i = 0; i < MAX_MEASURES; i++) {
+        soundLevels[i] = 0;
+    }
+
+    // Open I2C1 for reading the sound meter module registers
+    if ((file = open("/dev/i2c-1", O_RDWR)) < 0)
+    {
+        perror("Failed to open I2C1!");
+        exit(1);
+    }
+
+    // 0x48 is the decibel meter I2C address
+    if (ioctl(file, I2C_SLAVE, 0x48) < 0)
+    {
+        perror("db Meter module is not connected/recognized at I2C addr = 0x48");
+        close(file);
+        exit(1);
+    }
+
+    while (1)
+    {
+        // Decibel value is stored in register 0x0A
+        data = 0x0A;
+
+        // Write: send 1 byte from data (memory address pointer) to file
+        if (write(file, &data, 1) != 1)
+        {
+            perror("Failed to write register 0x0A");
+            close(file);
+            exit(1);
+        }
+
+        // Read the sound level from register 0x0A
+        if (read(file, &data, 1) != 1)
+        {
+            perror("Failed to read register 0x0A");
+            close(file);
+            exit(1);
+        }
+
+        // Insert the new reading into the array
+        sum -= soundLevels[index];  // Subtract the old value to maintain the sum
+        soundLevels[index] = data;  // Store the new value
+        sum += soundLevels[index];  // Add the new value to the sum
+
+        // Move to the next index, wrap around if needed
+        index = (index + 1) % MAX_MEASURES;
+
+        // Calculate the moving average (sum of the last 60 values)
+        int movingAverage = sum / MAX_MEASURES;
+
+        
+
+        // Find the max and min values in the soundLevels array
+        int max = soundLevels[0];
+        int min = soundLevels[0];
+        for (i = 1; i < MAX_MEASURES; i++)
+        {
+            if (soundLevels[i] > max) {
+                max = soundLevels[i];
+            }
+            if (soundLevels[i] < min) {
+                min = soundLevels[i];
+            }
+        }
+
+         // Open the file to write the moving average (overwrite)
+        fileOutput = fopen("/var/www/nebuleair_pro_4g/sound_meter/moving_avg_minute.txt", "w");
+
+        if (fileOutput == NULL)
+        {
+            perror("Failed to open file for writing");
+            close(file);
+            exit(1);
+        }
+        // Write the moving average to the file
+        fprintf(fileOutput, "%d %d %d\n", movingAverage, max, min);
+         // Close the file after writing
+        fclose(fileOutput);
+
+        // Display the current sound level and the moving average
+        printf("Current Sound level: %d\n", data);
+        printf("Current index: %d\n", index);
+
+        printf("Sound levels array: ");
+        for (i = 0; i < MAX_MEASURES; i++)
+        {
+            printf("%d ", soundLevels[i]);
+        }
+        printf("\nMax Sound level: %d\n", max);
+        printf("Min Sound level: %d\n", min);
+        printf("Moving Average (Last 60 seconds): %d\n\n", movingAverage);
+
+
+        // Wait for 1 second before taking the next measurement
+        sleep(1);
+    }
+
+    close(file);
+    return 0;
+}