From e9205c88fae477ba98f5fb297dcff124f609537b Mon Sep 17 00:00:00 2001
From: Jose <joseraj@gmail.com>
Date: Fri, 25 Apr 2025 08:57:10 +0200
Subject: [PATCH] Dynamic rangelimit on serial

---
 src/main.cpp | 72 ++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 67 insertions(+), 5 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 3df1c9c..8b230eb 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,5 +1,6 @@
 #include <Arduino.h>
 #include <driver/i2s.h>
+#include <deque>
 
 // you shouldn't need to change these settings
 #define SAMPLE_BUFFER_SIZE 512
@@ -11,13 +12,67 @@
 #define I2S_MIC_LEFT_RIGHT_CLOCK 9
 #define I2S_MIC_SERIAL_DATA 10
 
+// Add sample history tracking for range limiting
+#define HISTORY_DURATION_MS 3000  // 3 seconds history
+#define SAMPLES_PER_MS (SAMPLE_RATE / 1000)
+#define HISTORY_SIZE (HISTORY_DURATION_MS * SAMPLES_PER_MS)
+
+class AudioLevelTracker {
+public:
+    AudioLevelTracker() {
+        resetMaxLevel();
+    }
+
+    void updateMaxLevel(int32_t sample) {
+        uint32_t currentTime = millis();
+        
+        // Remove old samples (older than 10 seconds)
+        while (!sampleHistory.empty() && 
+               (currentTime - sampleHistory.front().timestamp) > HISTORY_DURATION_MS) {
+            sampleHistory.pop_front();
+        }
+
+        // Add new sample
+        int32_t absValue = abs(sample);
+        SamplePoint newPoint = {currentTime, absValue};
+        sampleHistory.push_back(newPoint);
+
+        // Update maximum
+        maxLevel = 0;
+        for (const auto& point : sampleHistory) {
+            if (point.value > maxLevel) {
+                maxLevel = point.value;
+            }
+        }
+    }
+
+    int32_t getMaxLevel() const {
+        return maxLevel;
+    }
+
+    void resetMaxLevel() {
+        maxLevel = 0;
+        sampleHistory.clear();
+    }
+
+private:
+    struct SamplePoint {
+        uint32_t timestamp;
+        int32_t value;
+    };
+    std::deque<SamplePoint> sampleHistory;
+    int32_t maxLevel;
+};
+
+AudioLevelTracker audioLevelTracker;
+
 // don't mess around with this
 i2s_config_t i2s_config = {
     .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
     .sample_rate = SAMPLE_RATE,
     .bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
     .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
-    .communication_format = I2S_COMM_FORMAT_I2S,
+    .communication_format = I2S_COMM_FORMAT_STAND_I2S,  // Updated from I2S_COMM_FORMAT_I2S
     .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
     .dma_buf_count = 4,
     .dma_buf_len = 1024,
@@ -48,17 +103,24 @@ void loop()
   size_t bytes_read = 0;
   i2s_read(I2S_NUM_0, raw_samples, sizeof(int32_t) * SAMPLE_BUFFER_SIZE, &bytes_read, portMAX_DELAY);
   int samples_read = bytes_read / sizeof(int32_t);
-  // dump the samples out to the serial channel.
+  
+  // Calculate dynamic range limit based on max level from last 10 seconds
+  int32_t currentMaxLevel = audioLevelTracker.getMaxLevel();
+  int32_t rangelimit = currentMaxLevel > 0 ? currentMaxLevel : 20000; // fallback to default if no history
+
+  // dump the samples out to the serial channel
   for (int i = 0; i < samples_read; i++)
   {
-    // False print statements to "lock range" on serial plotter display
-    // Change rangelimit value to adjust "sensitivity"
-    int rangelimit = 2000000;
+    // Update the max level tracker with current sample
+    audioLevelTracker.updateMaxLevel(raw_samples[i]);
+
+    // Print range limits for plotter
     Serial.print(rangelimit * -1);
     Serial.print(" ");
     Serial.print(rangelimit);
     Serial.print(" ");
 
+    // Print the actual sample
     Serial.printf("%ld\n", raw_samples[i]);
   }
 }
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