Floating-point code

pico-daq/.#pico_daq.cpp

@@ -0,0 +1 @@
+alex@Alexs-MBP.home.44315

pico-daq/pico_daq.cpp

@@ -14,15 +14,15 @@
 // 0     = 500,000 Hz
 // 960   = 50,000 Hz
 // 9600  = 5,000 Hz
-#define CLOCK_DIV 9600
+#define CLOCK_DIV 12000
 
 // Channel 0 is GPIO26
 #define CAPTURE_CHANNEL 0
 #define LED_PIN 25
-#define NSAMP 20000
+#define NSAMP 10000
 
 uint16_t capture_buf[NSAMP];
-uint16_t sending_buf[NSAMP];
+float sending_buf[NSAMP];
 
 int main() {
     stdio_init_all();
@@ -77,16 +77,26 @@ int main() {
       gpio_put(LED_PIN, 1);
       adc_run(true);
 
-      // first transmission will be garbage since we haven't filled the buffer yet
+      // first transmission will be garbage since we haven't filled buf
       std::string encoded =
-	base64_encode((unsigned char const *)sending_buf, NSAMP*2);
+	base64_encode((unsigned char const *)sending_buf, NSAMP*4);
+      
       printf("%s", encoded.c_str());
 
       gpio_put(LED_PIN, 0);
 
       dma_channel_wait_for_finish_blocking(dma_chan);
 
-      
-      memcpy(sending_buf, capture_buf, NSAMP*2);
+      uint16_t min = 32768;
+      uint16_t max = 0;
+	
+      for (uint32_t i=0; i<NSAMP; i++) {
+	if (capture_buf[i] > max) max = capture_buf[i];
+	if (capture_buf[i] < min) min = capture_buf[i];
+      }
+	    
+      for (uint32_t i=0; i<NSAMP; i++) {
+	features[i] = ((float)capture_buf[i]-(float)min)/((float)max-(float)min)*2-1;
+      }
     }
 }

pico-daq/py/b64_16_to_wave.py

@@ -3,8 +3,8 @@ import numpy as np
 import base64
 
 if __name__=="__main__":
-    infile = "/Users/alex/Desktop/pico/other-3"
-    outfile = "/Users/alex/Desktop/pico/other.wav"
+    infile = "/Users/alex/Desktop/4khz/extinguish"
+    outfile = "/Users/alex/Desktop/4khz/extinguish.wav"
 
     f = open(infile, "r")
 
@@ -28,7 +28,7 @@ if __name__=="__main__":
     audio = AudioSegment(
         data.tobytes(),
         sample_width=2,
-        frame_rate=5000,
+        frame_rate=4000,
         channels=1
     )
     

pico-daq/py/b64_float_to_wave.py

@@ -0,0 +1,48 @@
+from pydub import AudioSegment
+import scipy.io.wavfile
+import numpy as np
+import base64
+import io
+import matplotlib.pyplot as plt
+
+if __name__=="__main__":
+    infile = "/Users/alex/Desktop/float-test/noise"
+    outfile = "/Users/alex/Desktop/float-test/noise.wav"
+
+    f = open(infile, "r")
+
+    byte_data = bytearray()
+    vals = f.read(1000)
+    # Reading all at once didn't work for some reason
+    while vals:
+        byte_data.extend(base64.b64decode(vals))
+        vals = f.read(1000)
+        if len(vals) != 1000: break
+    f.close()
+
+    # Enforce little endian
+    dt = np.dtype(np.float32)
+    dt = dt.newbyteorder('<')
+
+    data = np.zeros(int(len(byte_data)/4), dtype=dt)
+    num_idx = 0
+    byte_idx = 0
+    while byte_idx < len(byte_data)-4:
+        num = np.frombuffer(byte_data[byte_idx:byte_idx+4], dtype=dt)
+        if (num > 1 or num < -1):
+            print("Skipped one")
+            byte_idx = byte_idx + 3
+        else:
+            data[num_idx] = num[0]
+            num_idx = num_idx+1
+            byte_idx = byte_idx + 4
+    
+    #plt.plot(data)
+    #plt.show()
+
+    wav_io = io.BytesIO()
+    scipy.io.wavfile.write(wav_io, 4000, data)
+    wav_io.seek(0)
+    sound = AudioSegment.from_wav(wav_io)
+        
+    sound.export(outfile, format="wav")