working ADC input + FFT analysis + py logger

plotter.py

@@ -0,0 +1,132 @@
+"""
+Live serial plotter for audio_analysis firmware.
+
+Reads prefixed lines from UART:
+  RAW:s0,s1,s2,...   → time-domain waveform (decimated by 4)
+  FFT:m0,m1,m2,...   → frequency-domain spectrum (first 128 bins)
+
+Usage:
+  python plotter.py COM5          # Windows
+  python plotter.py /dev/ttyACM0  # Linux
+
+Requirements:
+  pip install pyserial matplotlib numpy PyQt5
+"""
+
+import sys
+import threading
+import matplotlib
+matplotlib.use("Qt5Agg")
+import serial
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.animation import FuncAnimation
+
+# ── Config ──────────────────────────────────────────
+
+BAUD = 115200
+SAMPLE_RATE = 44100
+BUF_SIZE = 1024
+DECIMATION = 4
+DISPLAY_SAMPLES = BUF_SIZE // DECIMATION  # 256
+DISPLAY_BINS = 128
+
+# ── Serial setup ────────────────────────────────────
+
+if len(sys.argv) < 2:
+    print(f"Usage: python {sys.argv[0]} <COM_PORT>")
+    sys.exit(1)
+
+port = sys.argv[1]
+ser = serial.Serial(port, BAUD, timeout=0.1)
+
+# ── Plot setup ──────────────────────────────────────
+
+fig, (ax_time, ax_freq) = plt.subplots(2, 1, figsize=(10, 6))
+fig.suptitle("Audio Analysis — Live")
+
+# Time domain (decimated)
+time_x = np.arange(DISPLAY_SAMPLES) * DECIMATION / SAMPLE_RATE * 1000  # ms
+time_line, = ax_time.plot(time_x, np.zeros(DISPLAY_SAMPLES), color="cyan")
+ax_time.set_xlim(0, time_x[-1])
+ax_time.set_ylim(-1.1, 1.1)
+ax_time.set_xlabel("Time (ms)")
+ax_time.set_ylabel("Amplitude")
+ax_time.set_title("Waveform")
+ax_time.grid(True, alpha=0.3)
+
+# Frequency domain (first DISPLAY_BINS bins)
+freq_x = np.arange(DISPLAY_BINS) * SAMPLE_RATE / BUF_SIZE  # Hz
+freq_line, = ax_freq.plot(freq_x, np.zeros(DISPLAY_BINS), color="orange")
+ax_freq.set_xlim(0, freq_x[-1])
+ax_freq.set_ylim(0, 1)
+ax_freq.set_xlabel("Frequency (Hz)")
+ax_freq.set_ylabel("Magnitude")
+ax_freq.set_title("Spectrum")
+ax_freq.grid(True, alpha=0.3)
+
+plt.tight_layout()
+
+# ── Thread-safe data storage ───────────────────────
+
+lock = threading.Lock()
+raw_data = np.zeros(DISPLAY_SAMPLES)
+fft_data = np.zeros(DISPLAY_BINS)
+
+# ── Background serial reader thread ───────────────
+
+def serial_reader():
+    global raw_data, fft_data
+
+    while True:
+        try:
+            raw_line = ser.readline()
+            if not raw_line:
+                continue
+            line = raw_line.decode("utf-8", errors="ignore").strip()
+        except Exception:
+            continue
+
+        if line.startswith("RAW:"):
+            try:
+                values = line[4:].split(",")
+                samples = np.array([int(v) for v in values if v],
+                                   dtype=np.float32)
+                normalized = (samples - 2048.0) / 2048.0
+                with lock:
+                    raw_data = normalized[:DISPLAY_SAMPLES]
+            except (ValueError, IndexError):
+                pass
+
+        elif line.startswith("FFT:"):
+            try:
+                values = line[4:].split(",")
+                mags = np.array([float(v) for v in values if v])
+                with lock:
+                    fft_data = mags[:DISPLAY_BINS]
+            except (ValueError, IndexError):
+                pass
+
+reader_thread = threading.Thread(target=serial_reader, daemon=True)
+reader_thread.start()
+
+# ── Animation update ────────────────────────────────
+
+def update(frame):
+    with lock:
+        rd = raw_data.copy()
+        fd = fft_data.copy()
+
+    time_line.set_ydata(rd)
+
+    freq_line.set_ydata(fd)
+    peak = np.max(fd)
+    if peak > 0:
+        ax_freq.set_ylim(0, peak * 1.2)
+
+    return time_line, freq_line
+
+ani = FuncAnimation(fig, update, interval=100, blit=False, cache_frame_data=False)
+
+plt.show()
+ser.close()