1 files changed, 153 insertions, 0 deletions
diff --git a/airspy_waterfall.py b/airspy_waterfall.py
new file mode 100644
index 0000000..255ecd5
--- /dev/null
+++ b/airspy_waterfall.py
@@ -0,0 +1,153 @@
+import os
+import sys
+import math
+
+import airspyhf
+
+import matplotlib
+import numpy
+import pylab
+
+import pygame
+from pygame import gfxdraw
+
+CENTER_FREQ = 4e6
+SAMPLE_RATE = 196e3
+SAMPLE_NUM = 2048
+GAIN = 'auto'
+
+SCREEN_X = 1025
+SCREEN_Y = 320
+
+MOVE_STEP = 0.1e6
+
+# init RTLSDR and if no then go out
+try:
+    pass
+except IOError:
+    print
+    "Probably RTLSDR device not attached"
+    sys.exit(0)
+
+# config rtlsdr device
+#rtl.sample_rate = SAMPLE_RATE
+#rtl.center_freq = CENTER_FREQ
+#rtl.gain = GAIN
+
+
+def iq_abs(c):
+    return (math.sqrt((c.real ** 2 + c.imag ** 2)))
+
+
+# point should be normalised to 0.0 ... 1.0
+def color_normalise(point):
+    ret = (255, 0, 0)
+    # blue
+    if (point < 0.3):
+        ret = (0, 0, int(point * 255 * 3.3))
+    # yello
+    elif (point < 0.7):
+        ret = (0, int((point - 0.3) * 255 * 2.5), 0)
+    # red
+    elif (point <= 1.0):
+        ret = (int((point - 0.7) * 255 * 3.3), 0, 0)
+    else:
+        # print "Color Error ", point
+        pass
+    return ret
+
+
+def color_mapping(x):
+    "assumes -50 to 0 range, returns color"
+    r = int((x + 50) * 255 // 50)
+    r = max(0, r)
+    r = min(255, r)
+    return (r, r, 100)
+
+
+# def draw_Hz( surface, x, y, hz ):
+
+
+arr = [[0 for i in range(0, SCREEN_X)] for j in range(0, SCREEN_Y)]
+
+# init all pygame modules audio,video and more
+pygame.init()
+
+# [NEW] creates screen surface using constants
+screen = pygame.display.set_mode((SCREEN_X, SCREEN_Y))
+
+#samples = rtl.read_samples(SAMPLE_NUM)
+samples = []
+
+run = True
+line = 0
+while run:
+
+    # print "update"
+
+    # check for all events that where ocure
+    for event in pygame.event.get():
+        # if some one clicked on close button
+        if event.type == pygame.QUIT:
+            # terminate programm
+            run = False
+            # don't waste your time by waiting while event loop will end
+            break
+        elif event.type == pygame.KEYDOWN:
+            if event.key == pygame.K_LEFT:
+                print
+                "Left"
+                rtl.center_freq -= MOVE_STEP
+                print
+                "Center freq: ", rtl.center_freq, " Hz"
+            elif event.key == pygame.K_RIGHT:
+                print
+                "Right"
+                rtl.center_freq += MOVE_STEP
+                print
+                "Center freq: ", rtl.center_freq, " Hz"
+
+    width = SCREEN_X
+    height = SCREEN_Y
+
+    samples = rtl.read_samples(SAMPLE_NUM)
+    spect = numpy.fft.fft(samples)
+    spect = spect[0:len(spect) / 2]
+
+    # (1/(Fs*N)) * abs(xdft).^2;
+    spect_n = [(1.0 / (SAMPLE_NUM * len(spect))) * iq_abs(x) ** 2 for x in spect]
+    spect_n = (10 * numpy.log10(spect_n)).tolist()
+
+    # total data size
+    spect_len = len(spect_n)
+
+    # calculate amount spect points per pixel without rounding
+    pixel_width = spect_len / SCREEN_X + 1
+    pixel_steps = spect_len / pixel_width
+
+    for step in range(0, pixel_steps):
+        avg = 0.0
+        for i in range(0, pixel_width):
+            avg += spect_n[step * pixel_width + i]
+        avg /= pixel_width
+
+        # print avg
+        # gfxdraw.pixel( screen, step, line, color_normalise((100-abs(avg))/10))
+        gfxdraw.pixel(screen, step, line, color_mapping(avg))
+
+    # draw central freq
+    font = pygame.font.Font(None, 20)
+    text = font.render(str(rtl.center_freq / 1e6), 1, (200, 30, 30), (0, 0, 0))
+    screen.blit(text, (SCREEN_X / 2, SCREEN_Y - 20))
+    text = font.render(str((rtl.center_freq + SAMPLE_RATE / 2) / 1e6), 1, (200, 30, 30), (0, 0, 0))
+    screen.blit(text, (SCREEN_X - 40, SCREEN_Y - 20))
+    text = font.render(str((rtl.center_freq - SAMPLE_RATE / 2) / 1e6), 1, (200, 30, 30), (0, 0, 0))
+    screen.blit(text, (20, SCREEN_Y - 20))
+
+    pygame.display.flip()
+    line += 1
+    if (line > SCREEN_Y):
+        line = 0
+
+pygame.quit
+