decimation working

python/filter_design.py

@@ -0,0 +1,26 @@
+import numpy as np
+import scipy
+from matplotlib import pyplot as plt
+
+def main():
+    # Design some filter coefficients
+    n_taps = 33
+    cutoff = 1 / 2
+    filt_coeffs = scipy.signal.firwin(n_taps, cutoff)
+    nfft = 1024
+    filt_resp = np.fft.fft(filt_coeffs, nfft)
+    filt_resp = np.fft.fftshift(filt_resp)
+
+    freq_axis = (np.arange(nfft) - (nfft/2)) / nfft
+
+    plt.figure()
+    plt.plot(freq_axis, 20*np.log10(np.abs(filt_resp)))
+    plt.ylabel('dB')
+    plt.xlabel('Normalized Frequency')
+    plt.title('Filter Response')
+    plt.grid()
+    plt.show()
+
+if __name__ == '__main__':
+
+    main()

python/radar_manager.py

@@ -329,7 +329,7 @@ class RadarManager:
         self.axi_write_register(TIMING_ENGINE_ADDR + 0x8, num_pulses)
         self.axi_write_register(TIMING_ENGINE_ADDR + 0x10, inter_cpi - 1)
 
-    def setup_rx(self, num_samples, start_sample):
+    def setup_rx(self, num_samples, start_sample, dec_rate):
         for i in range(NUM_RX):
             if JESD204B:
                 self.axi_write_register(DIG_RX_ADDR + i*DIG_RX_STRIDE + 0x4, num_samples >> 1)
@@ -338,6 +338,10 @@ class RadarManager:
                 self.axi_write_register(DIG_RX_ADDR + i*DIG_RX_STRIDE + 0x4, num_samples >> 2)
                 self.axi_write_register(DIG_RX_ADDR + i*DIG_RX_STRIDE + 0x8, start_sample >> 2)
 
+            # Decimation Selection
+            dec_sel = int(np.log2(dec_rate))
+            self.axi_write_register(DIG_RX_ADDR + i * DIG_RX_STRIDE + 0xC, dec_sel)
+
             # Setup RX Strobe
             # self.axi_write_register(TIMING_ENGINE_ADDR + 0x88 + i * 8, start_sample >> 2)
             # self.axi_write_register(TIMING_ENGINE_ADDR + 0x8C + i * 8, num_samples >> 2)
@@ -384,9 +388,9 @@ class RadarManager:
 
 
     def configure_cpi(self, pri, inter_cpi, num_pulses, num_samples, start_sample,
-                      tx_num_samples, tx_start_sample, rx_lo_offset, tx_lo_offset):
-        self.load_waveform(0, 1, 0.1, tx_num_samples)
-        self.load_waveform(1, 1, 0.1, tx_num_samples)
+                      tx_num_samples, tx_start_sample, rx_lo_offset, tx_lo_offset, dec_rate):
+        self.load_waveform(0, 1, 0.05, tx_num_samples)
+        self.load_waveform(1, 1, 0.05, tx_num_samples)
 
         num_samples_quant = int(self.packet_size / 4)
         if num_samples % num_samples_quant > 0:
@@ -400,7 +404,7 @@ class RadarManager:
         self.setup_rf_attenuators(rf_atten)
 
         adc_nco = 1e9 % f_adc
-        dac_nco = 1.001e9 % f_dac
+        dac_nco = 1e9 % f_dac
 
         # adc_nco = 2e9
         # adc_nyquist_zone = np.floor(adc_nco / (f_adc / 2))
@@ -416,7 +420,7 @@ class RadarManager:
             self.set_dac_nco(i, dac_nco)
 
         self.setup_timing_engine(pri, num_pulses, inter_cpi)
-        self.setup_rx(num_samples, start_sample)
+        self.setup_rx(num_samples, start_sample, dec_rate)
         self.setup_tx(tx_num_samples, tx_start_sample)
         self.setup_cpi_header(pri, inter_cpi, num_pulses, num_samples, start_sample,
                       tx_num_samples, tx_start_sample, rx_lo_offset, tx_lo_offset)

python/read_data_file.py

@@ -25,7 +25,7 @@ def main():
     headers = []
     offset = 0
 
-    file = 'test1.bin'
+    file = 'test0.bin'
     fid = open(file, 'rb')
 
     # Find header, recording buffer could have wrapped depending on data rate and how long we ran for
@@ -86,21 +86,21 @@ def main():
     vmin = -60
     vmax = 0
 
-    plt.figure()
-    plt.plot(np.diff(cpi_times))
-    plt.plot(np.diff(pps_frac))
-    # plt.ylim([0, .04])
+    # plt.figure()
+    # plt.plot(np.diff(cpi_times))
+    # plt.plot(np.diff(pps_frac))
+    # # plt.ylim([0, .04])
 
-    # plt.figure()
-    # plt.plot(iq.T.real, '.-')
-    # plt.plot(iq.T.imag, '--.')
-    # plt.grid()
-    #
-    # plt.figure()
-    # plt.imshow(db20n(iq), aspect='auto', interpolation='nearest', vmin=vmin, vmax=vmax)
-    # plt.ylabel('Pulse Count')
-    # plt.xlabel('Sample Count')
-    # plt.colorbar()
+    plt.figure()
+    plt.plot(iq.T.real, '.-')
+    plt.plot(iq.T.imag, '--.')
+    plt.grid()
+
+    plt.figure()
+    plt.imshow(db20n(iq), aspect='auto', interpolation='nearest', vmin=vmin, vmax=vmax)
+    plt.ylabel('Pulse Count')
+    plt.xlabel('Sample Count')
+    plt.colorbar()
 
 
     plt.show()

python/test_cpi.py

@@ -45,9 +45,9 @@ def main():
     # CPI Parameters (timing values are in clk ticks)
     num_pulses = 128
     # Should be multiple of udp packet size, currently 4096 bytes, or 1024 samples
-    num_samples = 16384
+    num_samples = 4096
     start_sample = 2000
-    tx_num_samples = 1024
+    tx_num_samples = 4096
     tx_start_sample = start_sample
     prf = 8000
     pri = int(1/prf * clk)
@@ -57,11 +57,13 @@ def main():
     inter_cpi = 20000
     tx_lo_offset = 10e6
     rx_lo_offset = 0
-    test_duration = 60
+    dec_rate = 16
+    test_duration = 2
 
     pri_float = pri / clk
 
     print('PRI', pri_float, 'PRF', 1 / pri_float)
+    print('Sampling Duration (usec)', (tx_num_samples / radar_manager.BASEBAND_SAMPLE_RATE * dec_rate)/1e-6)
     print('Expected Data Rate', num_samples * 4 / pri_float / 1e6)
 
 
@@ -72,7 +74,8 @@ def main():
     recorder1.start_recording('test1.bin', True)
 
     radar.configure_cpi(pri, inter_cpi, num_pulses, num_samples, start_sample,
-                        tx_num_samples, tx_start_sample, rx_lo_offset, tx_lo_offset)
+                        tx_num_samples, tx_start_sample, rx_lo_offset, tx_lo_offset,
+                        dec_rate)
 
     print('Start Running')
     radar.start_running()