experimental version busing the built-in DAC (kinda broken)

UNITS.INI

@@ -2,6 +2,9 @@
 ## GEX v1.0.0 on STM32F072-HUB
 ## built Jun 15 2018 at 13:45:28
 
+# Overwrite this file to change settings.
+# Press the LOCK button to save them to Flash.
+
 [UNITS]
 # Create units by adding their names next to a type (e.g. DO=A,B),
 # remove the same way. Reload to update the unit sections below.
@@ -31,7 +34,7 @@ TOUCH=
 # Simple PWM output
 PWMDIM=
 # Two-channel analog output with waveforms
-DAC=
+DAC=dac
 
 [SPI:spi@2]
 # Peripheral number (SPIx)
@@ -55,7 +58,7 @@ first-bit=MSB
 # SS port name
 port=A
 # SS pins (comma separated, supports ranges)
-pins=4
+pins=3
 
 [ADC:adc@4]
 # Enabled channels, comma separated
@@ -73,7 +76,7 @@ frequency=1000
 # - defines the maximum pre-trigger size (divide by # of channels)
 # - captured data is sent in half-buffer chunks
 # - buffer overrun aborts the data capture
-buffer_size=512
+buffer_size=800
 
 # Enable continuous sampling with averaging
 # Caution: This can cause DAC output glitches
@@ -81,4 +84,17 @@ averaging=N
 # Exponential averaging coefficient (permil, range 0-1000 ~ 0.000-1.000)
 # - used formula: y[t]=(1-k)*y[t-1]+k*u[t]
 # - not available when a capture is running
-avg_factor=800
+avg_factor=80
+
+[DAC:dac@1]
+# Enabled channels (1:A4, 2:A5)
+ch1_enable=Y
+ch2_enable=N
+# Enable output buffer
+ch1_buff=Y
+ch2_buff=Y
+# Superimposed noise type (NONE,WHITE,TRIANGLE) and nbr. of bits (1-12)
+ch1_noise=NONE
+ch1_noise-level=3
+ch2_noise=NONE
+ch2_noise-level=3

main.py

@@ -7,6 +7,8 @@ from matplotlib import pyplot as plt
 import gex
 import time
 
+use_native_dac = True
+
 class ADG:
     def __init__(self, client:gex.Client):
         self.client = client
@@ -68,9 +70,12 @@ with gex.Client(gex.TrxRawUSB()) as client:
     
      
     # Frequency sweep parameters
-    f_0 = 5
+    #f_0 = 5
+    #f_1 = 5000
+    #f_step = 15
+    f_0 = 10
     f_1 = 5000
-    f_step = 15
+    f_step = 50
     
     # Retry on failure
     retry_count = 5
@@ -91,16 +96,28 @@ with gex.Client(gex.TrxRawUSB()) as client:
     
     adc = gex.ADC(client, 'adc')
     
-    gen = ADG(client)
-    gen.initialize()
+    dac = None
+    gen = None
+    
+    if use_native_dac:
+        print('Using native GEX DAC')
+        dac = gex.DAC(client, 'dac')
+        dac.waveform(1, 'SINE')
+    else:
+        print('Using AD9833 via SPI')
+        gen = ADG(client)
+        gen.initialize()
 
 
     table = []
     
     last_db = None
     for f in range(f_0, f_1, f_step):
-        #dac.set_frequency(1, f)
-        gen.set_frequency(f)
+      
+        if use_native_dac:
+            dac.set_frequency(1, f)
+        else:
+            gen.set_frequency(f)
         
         max_allowed_shift_db += allowed_shift_compensation
 
@@ -148,6 +165,7 @@ with gex.Client(gex.TrxRawUSB()) as client:
 
           y1 = np.max(t[:,0]) - np.min(t[:,0])
           y2 = np.max(t[:,1]) - np.min(t[:,1])
+          print("\x1b[90mU %f, Y %f\x1b[0m" % (y1, y2))
           gain_raw = y2/y1
           gain_db = 20*math.log10(gain_raw)
           
@@ -179,7 +197,10 @@ with gex.Client(gex.TrxRawUSB()) as client:
         if not suc:
           last_db = last_db_in_fail
 
-    gen.wfm_dc()
+    if use_native_dac:
+        dac.dc(1, 2000)
+    else:
+        gen.wfm_dc()
     
     t = np.reshape(np.array(table), [int(len(table) / 3), 3])