def run(self):
logging.debug("PulseDetector.run")
try:
sdr = RtlSdr()
sdr.rs = 2.4e6
sdr.fc = 146e6
sdr.gain = 10
except Exception as e:
logging.exception("SDR init failed")
return
last_max_mag = 0
leadingEdge = False
rgPulse = []
lastPulseTime = time.time()
#timeoutCount = 0
pulseCount = 0
while True:
# Handle change in frequency
try:
newFrequency = self.setFreqQueue.get_nowait()
except Exception as e:
pass
else:
logging.debug("Changing frequency %d", newFrequency)
sdr.fc = newFrequency
# Handle change in gain
try:
newGain = self.setGainQueue.get_nowait()
except Exception as e:
pass
else:
sdr.gain = newGain
logging.debug("Changing gain %d:%f", newGain, sdr.gain)
# Adjust noise threshold
sdrReopen = False
#noiseThreshold = self.calcNoiseThreshold(self.amp, sdr.gain)
#logging.debug("Noise threshold %f", noiseThreshold)
# Read samples
try:
samples = sdr.read_samples(NUM_SAMPLES_PER_SCAN)
except Exception as e:
logging.exception("SDR read failed")
sdrReopen = True
if sdrReopen:
logging.debug("Attempting reopen")
try:
sdr.open()
except Exception as e:
logging.exception("SDR reopen failed")
return
try:
samples = sdr.read_samples(NUM_SAMPLES_PER_SCAN)
except Exception as e:
logging.exception("SDR read failed")
return
# Process samples
mag, freqs = magnitude_spectrum(samples, Fs=sdr.rs)
if not leadingEdge:
# Detect leading edge
strength = self.detectedPulseStrength(mag)
if strength:
leadingEdge = True
#logging.debug("leading edge strength:background %d %d", strength, self.backgroundNoise)
rgPulse = [strength]
else:
# Detect trailing edge falling below background noise
strength = self.detectedPulseStrength(mag)
if strength:
rgPulse.append(strength)
else:
leadingEdge = False
pulseCaptureCount = len(rgPulse)
self.adjustBackgroundNoise(strength)
if pulseCaptureCount >= self.minPulseCaptureCount:
pulseStrength = max(rgPulse)
pulseCount += 1
logging.debug(
"***** %d %d %d pulseStrength:len(rgPulse):background",
pulseStrength, pulseCaptureCount,
self.backgroundNoise)
if self.pulseQueue:
self.pulseQueue.put(pulseStrength)
lastPulseTime = time.time()
else:
logging.debug("pulse too short %d", pulseCaptureCount)
for skippedStrength in rgPulse:
self.adjustBackgroundNoise(skippedStrength)
rgPulse = []
# Check for no pulse
if time.time() - lastPulseTime > 3:
#timeoutCount += 1
if leadingEdge:
leadingEdge = False
logging.error(
"failed to detect trailing edge - len(rgPulse):background %d %d",
len(rgPulse), self.backgroundNoise)
else:
logging.debug("no pulse for two seconds - background %d",
self.backgroundNoise)
if self.pulseQueue:
self.pulseQueue.put(0)
rgPulse = []
lastPulseTime = time.time()
sdr.close()
