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complete DMI code, untested

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parent
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dcd8babc67
2 changed files with 46 additions and 10 deletions
  1. +16
    -10
      dmi.py
  2. +30
    -0
      noptica.py

stabilize.py → dmi.py View File

@@ -1,40 +1,46 @@
import SoapySDR
import numpy as np
from scipy.signal import blackmanharris

from stabilizer import InductionHeater, Stabilizer
from noptica import InductionHeater, Stabilizer, PositionTracker


def main():
freq_sample = 5e6
freq_base = 1086e6
bufsize = 4096

induction = InductionHeater("/dev/ttyUSB0", 430e3, 445e3)
induction.start()
try:
stabilizer = Stabilizer(freq_sample, 0.4, 1088.3e6 - freq_base, 200e-6, induction)
position_tracker = PositionTracker(int(0.1*freq_sample/bufsize))

sdr = SoapySDR.Device()
sdr.setSampleRate(SoapySDR.SOAPY_SDR_RX, 0, freq_sample)
sdr.setFrequency(SoapySDR.SOAPY_SDR_RX, 0, base_freq)
for channel in range(2):
sdr.setSampleRate(SoapySDR.SOAPY_SDR_RX, channel, freq_sample)
sdr.setFrequency(SoapySDR.SOAPY_SDR_RX, channel, freq_base)

samples = np.array([0]*4096, np.complex64)
rx_stream = sdr.setupStream(SoapySDR.SOAPY_SDR_RX, SoapySDR.SOAPY_SDR_CF32)
samples_ref = np.array([0]*bufsize, np.complex64)
samples_meas = np.array([0]*bufsize, np.complex64)
rx_stream = sdr.setupStream(SoapySDR.SOAPY_SDR_RX, SoapySDR.SOAPY_SDR_CF32, [0, 1])
try:
sdr.activateStream(rx_stream)
try:
# We can't update faster than the MHS5200A serial interface
stabilizer_throttle = 0
while True:
sr = sdr.readStream(rx_stream, [samples], len(samples))
if sr.ret != len(samples):
sr = sdr.readStream(rx_stream, [samples_ref, samples_meas], bufsize)
if sr.ret != bufsize:
print("SDR sampling error")
return

# We can't update faster than the MHS5200A serial interface
stabilizer_throttle += 1
if stabilizer_throttle == 30:
stabilizer.input(samples)
stabilizer.input(samples_ref)
stabilizer_throttle = 0

position, leakage = position_tracker.input(samples_ref, samples_meas)
print(np.sum(position)/len(position), leakage)
finally:
sdr.deactivateStream(rx_stream)
finally:

stabilizer.py → noptica.py View File

@@ -1,6 +1,7 @@
import serial
import queue
import threading

import numpy as np
from scipy.signal import blackmanharris

@@ -70,3 +71,32 @@ class Stabilizer:
else:
tuning = 0.0
self.tuner.set(tuning)


def continuous_unwrap(last_phase, last_phase_unwrapped, p):
# note: np.unwrap always preserves first element of array
p = np.unwrap(p)
glue = np.array([last_phase_unwrapped, last_phase_unwrapped + (p[0] - last_phase)])
new_p0 = np.unwrap(glue)[1]
return new_p0 + p - p[0]


class PositionTracker:
def __init__(self, leakage_avg):
self.last_phase = 0.0
self.last_position = 0.0
self.leakage = np.zeros(leakage_avg)
self.leakage_ptr = 0

def input(self, ref, meas):
demod = np.conjugate(ref)*meas

self.leakage[self.leakage_ptr] = np.real(np.sum(demod)/len(demod))
self.leakage_ptr = (self.leakage_ptr + 1) % len(self.leakage)
leakage = np.sum(self.leakage)/len(self.leakage)

phase = np.angle(demod - leakage)
position = continuous_unwrap(self.last_phase, self.last_position, phase)/(2.0*np.pi)
self.last_phase = phase[-1]
self.last_position = position[-1]
return position, leakage

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