Pretty graphs and stable results

firmware/offset_test.py

@@ -7,18 +7,18 @@ from datetime import datetime
 
 from pyBusPirateLite import Buspirate
 
-AVERAGE_READINGS = 16
-
 if __name__ == '__main__':
     import argparse
 
     parser = argparse.ArgumentParser()
     parser.add_argument('channels', type=str, help='olsndot channels to test, format: 0-3,5,7,8-10')
-    parser.add_argument('run_name')
+    parser.add_argument('run_name', nargs='?', default=None)
     parser.add_argument('olsndot_port', nargs='?', default='/dev/serial/by-id/usb-FTDI_FT232R_USB_UART_A50285BI-if00-port0')
-    parser.add_argument('buspirate_port', nargs='?', default='/dev/serial/by-id/usb-FTDI_FT232R_USB_UART_AD01W1RF-if00-port0') # FIXME
-    parser.add_argument('-d', '--database', nargs='?', default='results.sqlite3', help='sqlite3 database file to store results in')
-    parser.add_argument('-m', '--mac', type=int, nargs='?', default=0xDEBE10BB, help='olsndot MAC address')
+    parser.add_argument('buspirate_port', nargs='?', default='/dev/serial/by-id/usb-FTDI_FT232R_USB_UART_AD01W1RF-if00-port0')
+    parser.add_argument('-d', '--database', default='results.sqlite3', help='sqlite3 database file to store results in')
+    parser.add_argument('-m', '--mac', type=int, default=0xDEBE10BB, help='olsndot MAC address')
+    parser.add_argument('-w', '--wait', type=float, default=0.1, help='time to wait between samples in seconds')
+    parser.add_argument('-o', '--oversample', type=int, default=16, help='oversampling ratio')
     args = parser.parse_args()
 
     def parse_channels(channels):
@@ -55,25 +55,38 @@ if __name__ == '__main__':
 
     uut = Olsndot(args.mac)
     d = Driver(args.olsndot_port, devices=[uut])
-
+    uut.send_framebuf([0]*uut.nchannels)
     print('Connected to uut:', uut)
 
+    run_name = args.run_name
+    if args.run_name is None:
+        names = [ n[4:] for n, in db.execute('SELECT name FROM runs WHERE name LIKE "test%"').fetchall() ]
+        run_name = 'test{}'.format(1+max(int(n) if str.isnumeric(n) else 0 for n in names))
     with db:
         cur = db.cursor()
         cur.execute('INSERT INTO runs(name, uut_mac, timestamp) VALUES (?, ?, ?)',
-                (args.run_name, args.mac, time.time()))
+                (run_name, args.mac, time.time()))
         run_id = cur.lastrowid
-    print('Starting run {} at {:%y-%m-%d %H:%M:%S:%f}'.format(run_id, datetime.now()))
+    print('Starting run {} "{}" at {:%y-%m-%d %H:%M:%S:%f}'.format(run_id, run_name, datetime.now()))
     print('mac={:08x} channels={}'.format(args.mac, ','.join('{:02d}'.format(ch) for ch in channels)))
     print('[measurement id] " " [hex setpoint value] "(" [float duty cycle] ")" " " [reading (V)]')
 
+    # zero cal
+    uut.send_framebuf([0]*uut.nchannels)
+    time.sleep(args.wait)
+    readings = [ bp.adc_value for _ in range(args.oversample) ]
+    mean, stdev = statistics.mean(readings), statistics.stdev(readings)
+    cur.execute('''
+        INSERT INTO measurements (
+                run_id, channel, duty_cycle, voltage, voltage_stdev, timestamp
+            ) VALUES (?, -1, 0, ?, ?, ?)''',
+            (run_id, mean, stdev, time.time()))
+    print('Zero cal: {:5.4f}V stdev={:5.4f}V'.format(mean, stdev))
+
     for ch in channels:
-        for i in range(-1, uut.nbits):
+        for i in range(uut.nbits):
             fb = [0]*uut.nchannels
-            if i == -1:
-                val = 0
-            else:
-                val = 1<<i
+            val = 1<<i
             duty_cycle = val/(2**uut.nbits)
             extra_shift = 16-uut.nbits
             val <<= extra_shift
@@ -81,8 +94,8 @@ if __name__ == '__main__':
             fb[ch] = val
             uut.send_framebuf(fb)
             
-            time.sleep(0.2)
-            readings = [ bp.adc_value for _ in range(AVERAGE_READINGS) ]
+            time.sleep(args.wait)
+            readings = [ bp.adc_value for _ in range(args.oversample) ]
             mean, stdev = statistics.mean(readings), statistics.stdev(readings)
 
             with db: