Add audio visualizer client and server, spi driver speed improvements

raspledstrip/LPD8806.py

@@ -48,11 +48,8 @@ def __init__(self, led_count):
             raise Exception("SPI module not available")
         self.spi = spidev.SpiDev()
         self.spi.open(0, 0)
-        self.spi.max_speed_hz = 12000000
+        self.spi.max_speed_hz = 18000000
         print 'py-spidev MHz: %d' % (self.spi.max_speed_hz / 1000000.0)
 
     def update(self, pixel_buffer):
-        for led in xrange(self.led_count):
-            self.spi.xfer2([i for i in pixel_buffer[led]])
-        self.spi.xfer2([0x00, 0x00, 0x00]) #zero fill the last to prevent stray colors at the end
-        self.spi.xfer2([0x00]) #once more with feeling - this helps :)
+        self.spi.xfer2([item for sublist in pixel_buffer for item in sublist]+[0x00, 0x00, 0x00])

requirements.txt

@@ -1,2 +1,4 @@
 mock==1.0.1
-nose==1.3.3
+nose==1.3.3
+PyAudio==0.2.8
+numpy==1.8.1

visualize_audio_client.py

@@ -0,0 +1,80 @@
+import wave
+import pyaudio
+import numpy
+import socket
+import struct
+
+LED_DRIVER_HOST = '0.0.0.0'  #Set this to the address of the raspberry pi with the LEDs attached
+#LED_DRIVER_HOST = 'localhost'
+LED_DRIVER_PORT = 50007
+BUFFER_SIZE = 512
+
+
+def main():
+    display_buffer = [bytearray([0x00, 0x00, 0x00]) for i in xrange(36)]
+
+    #input_stream = FileReader('8k8bitpcm.wav')  # local file for testing
+    input_stream = LiveReader()
+    output_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+
+    def lpush(buffer, byte):
+        def lpush_iter(buffer, pos, byte):
+            if pos < len(buffer):
+                current_byte = buffer[pos]
+                buffer[pos] = byte
+                return lpush_iter(buffer, pos+1, current_byte)
+            else:
+                return buffer
+
+        return lpush_iter(buffer, 0, byte)
+
+    audio_bytes = input_stream.read_bytes(BUFFER_SIZE)
+
+    while audio_bytes:
+        buf = numpy.frombuffer(audio_bytes, dtype=numpy.int8)
+        window = numpy.hanning(len(buf))
+        buf = buf * window
+        fourier = numpy.fft.rfft(buf, 8)
+
+        power = numpy.abs(fourier)
+        spectrum = (power * 255/power.max()).astype(numpy.int8).clip(0)
+        element = bytearray([spectrum[1], spectrum[2], spectrum[3]])
+
+        display_buffer = lpush(display_buffer, element)
+        buf = ""
+        for pixel in display_buffer:
+            buf += struct.pack('BBB', *pixel)
+        output_socket.sendto(
+            buf,
+            (LED_DRIVER_HOST, LED_DRIVER_PORT)
+        )
+        audio_bytes = input_stream.read_bytes(BUFFER_SIZE)
+
+
+class AudioReader(object):
+    def read_bytes(self, buffer_size):
+        pass
+
+
+class FileReader(AudioReader):
+    def __init__(self, file_name):
+        self._fp = wave.open(file_name, 'r')
+
+    def read_bytes(self, buffer_size):
+        return self._fp.readframes(buffer_size)
+
+
+class LiveReader(AudioReader):
+    def __init__(self):
+        self._paudio = pyaudio.PyAudio()
+        self._stream = self._paudio.open(
+            format=pyaudio.paInt8,
+            channels=1,
+            rate=16000,
+            input=True
+        )
+
+    def read_bytes(self, buffer_size):
+        return self._stream.read(buffer_size)
+
+main()

visualize_audio_server.py

@@ -0,0 +1,33 @@
+import socket
+import struct
+from raspledstrip.LPD8806 import LPD8806SPI
+led_strip = LPD8806SPI(36)
+
+HOST = ''
+PORT = 50007
+
+input_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+input_socket.bind((HOST, PORT))
+display_buffer = [bytearray([0x00, 0x00, 0x00]) for i in xrange(36)]
+gamma = [0x80 | int(pow(float(i) / 255.0, 2.5) * 127.0 + 0.5) for i in range(256)]
+
+
+def lpush(buffer, byte):
+    def lpush_iter(buffer, pos, byte):
+        if pos < len(buffer):
+            current_byte = buffer[pos]
+            buffer[pos] = byte
+            return lpush_iter(buffer, pos+1, current_byte)
+        else:
+            return buffer
+
+    return lpush_iter(buffer, 0, byte)
+
+
+while 1:
+    byte_buffer, from_addr = input_socket.recvfrom(36*3)
+    for i in xrange(36):
+        pixel = struct.unpack('BBB', byte_buffer[i*3:(i*3 + 3)])
+        display_buffer = lpush(display_buffer, bytearray([gamma[pixel[0]], gamma[pixel[1]], gamma[pixel[2]]]))
+    led_strip.update(display_buffer)
+    #print display_buffer