Merge branch 'master' of https://github.com/cogliano/Adafruit_Learning_System_Guides

Author: cogliano

Circuit_Playground_O_Phonor/freq_basic.py

@@ -0,0 +1,58 @@
+import time
+import array
+import board
+import audiobusio
+
+#---| User Configuration |---------------------------
+SAMPLERATE = 16000
+SAMPLES = 1024
+THRESHOLD = 100
+MIN_DELTAS = 5
+DELAY = 0.2
+#----------------------------------------------------
+
+# Create a buffer to record into
+samples = array.array('H', [0] * SAMPLES)
+
+# Setup the mic input
+mic = audiobusio.PDMIn(board.MICROPHONE_CLOCK,
+                       board.MICROPHONE_DATA,
+                       sample_rate=SAMPLERATE,
+                       bit_depth=16)
+
+while True:
+    # Get raw mic data
+    mic.record(samples, SAMPLES)
+
+    # Compute DC offset (mean) and threshold level
+    mean = int(sum(samples) / len(samples) + 0.5)
+    threshold = mean + THRESHOLD
+
+    # Compute deltas between mean crossing points
+    # (this bit by Dan Halbert)
+    deltas = []
+    last_xing_point = None
+    crossed_threshold = False
+    for i in range(SAMPLES-1):
+        sample = samples[i]
+        if sample > threshold:
+            crossed_threshold = True
+        if crossed_threshold and sample < mean:
+            if last_xing_point:
+                deltas.append(i - last_xing_point)
+            last_xing_point = i
+            crossed_threshold = False
+
+    # Try again if not enough deltas
+    if len(deltas) < MIN_DELTAS:
+        continue
+
+    # Average the deltas
+    mean = sum(deltas) / len(deltas)
+
+    # Compute frequency
+    freq = SAMPLERATE / mean
+
+    print("crossings: {}  mean: {}  freq: {} ".format(len(deltas), mean, freq))
+
+    time.sleep(DELAY)

Circuit_Playground_O_Phonor/freq_neopixel.py

@@ -0,0 +1,84 @@
+import time
+import array
+import board
+import audiobusio
+import simpleio
+import neopixel
+
+#---| User Configuration |---------------------------
+SAMPLERATE = 16000
+SAMPLES = 1024
+THRESHOLD = 100
+MIN_DELTAS = 5
+DELAY = 0.2
+
+FREQ_LOW = 520
+FREQ_HIGH = 990
+COLORS = (
+    (0xFF, 0x00, 0x00) , # pixel 0
+    (0xFF, 0x71, 0x00) , # pixel 1
+    (0xFF, 0xE2, 0x00) , # pixel 2
+    (0xAA, 0xFF, 0x00) , # pixel 3
+    (0x38, 0xFF, 0x00) , # pixel 4
+    (0x00, 0xFF, 0x38) , # pixel 5
+    (0x00, 0xFF, 0xA9) , # pixel 6
+    (0x00, 0xE2, 0xFF) , # pixel 7
+    (0x00, 0x71, 0xFF) , # pixel 8
+    (0x00, 0x00, 0xFF) , # pixel 9
+)
+#----------------------------------------------------
+
+# Create a buffer to record into
+samples = array.array('H', [0] * SAMPLES)
+
+# Setup the mic input
+mic = audiobusio.PDMIn(board.MICROPHONE_CLOCK,
+                       board.MICROPHONE_DATA,
+                       sample_rate=SAMPLERATE,
+                       bit_depth=16)
+
+# Setup NeoPixels
+pixels = neopixel.NeoPixel(board.NEOPIXEL, 10, auto_write=False)
+
+while True:
+    # Get raw mic data
+    mic.record(samples, SAMPLES)
+
+    # Compute DC offset (mean) and threshold level
+    mean = int(sum(samples) / len(samples) + 0.5)
+    threshold = mean + THRESHOLD
+
+    # Compute deltas between mean crossing points
+    # (this bit by Dan Halbert)
+    deltas = []
+    last_xing_point = None
+    crossed_threshold = False
+    for i in range(SAMPLES-1):
+        sample = samples[i]
+        if sample > threshold:
+            crossed_threshold = True
+        if crossed_threshold and sample < mean:
+            if last_xing_point:
+                deltas.append(i - last_xing_point)
+            last_xing_point = i
+            crossed_threshold = False
+
+    # Try again if not enough deltas
+    if len(deltas) < MIN_DELTAS:
+        continue
+
+    # Average the deltas
+    mean = sum(deltas) / len(deltas)
+
+    # Compute frequency
+    freq = SAMPLERATE / mean
+
+    print("crossings: {}  mean: {}  freq: {} ".format(len(deltas), mean, freq))
+
+    # Show on NeoPixels
+    pixels.fill(0)
+    pixel = round(simpleio.map_range(freq, FREQ_LOW, FREQ_HIGH, 0, 9))
+    pixels[pixel] = COLORS[pixel]
+    pixels.show()
+
+    time.sleep(DELAY)