1 files changed, 131 insertions, 0 deletions
diff --git a/doc/offset_test.py b/doc/offset_test.py
new file mode 100644
index 0000000..f2b8b2f
--- /dev/null
+++ b/doc/offset_test.py
@@ -0,0 +1,131 @@
+#!/usr/bin/env python3
+
+import time
+import statistics
+import sqlite3
+from olsndot import Olsndot, Driver
+from datetime import datetime
+
+from pyBusPirateLite import Buspirate
+
+if __name__ == '__main__':
+    import argparse
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('run_name', nargs='?', default='auto')
+    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')
+    parser.add_argument('-c', '--channels', nargs='?', default='auto', help='olsndot channels to test, format: 0-3,5,7,8-10')
+    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')
+    parser.add_argument('-b', '--bits', type=int, default=None, help='number of bits to sample')
+    args = parser.parse_args()
+
+    db = sqlite3.connect(args.database)
+    db.execute("""
+        CREATE TABLE IF NOT EXISTS runs (
+                run_id INTEGER PRIMARY KEY,
+                name TEXT,
+                comment TEXT,
+                uut_mac TEXT, -- hex-string formatted 32-bit mac of the uut
+                timestamp REAL -- unix timestamp in fractional seconds
+                )""")
+    db.execute("""
+        CREATE TABLE IF NOT EXISTS measurements (
+                measurement_id INTEGER PRIMARY KEY,
+                run_id INTEGER,
+                channel INTEGER,
+                duty_cycle REAL, -- setpoint duty cycle as a float between 0.0 and 1.0
+                voltage REAL, -- volts
+                voltage_stdev REAL, -- volts
+                timestamp REAL, -- unix timestamp in fractional seconds
+                FOREIGN KEY (run_id) REFERENCES runs)""")
+
+    bp = Buspirate(args.buspirate_port)
+    bp.power_on = True
+
+    uut = Olsndot(args.mac)
+    d = Driver(args.olsndot_port, devices=[uut])
+    print('Connected to uut:', uut)
+
+    run_name = args.run_name
+    if not str.isnumeric(args.run_name[-1]):
+        names = [ n[len(run_name):] for n, in db.execute(
+            'SELECT name FROM runs WHERE name LIKE ?||"%"', (run_name,)).fetchall() ]
+        names.append('0') # in case we get no results
+        run_name += str(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 (?, ?, ?)',
+                (run_name, args.mac, time.time()))
+        run_id = cur.lastrowid
+
+    nbits = args.bits if args.bits is not None else uut.nbits
+
+    def parse_channels(channels):
+        for spec in channels.split(','):
+            if str.isnumeric(spec):
+                yield int(spec)
+            else:
+                low, high = spec.split('-')
+                yield from range(int(low), int(high)+1)
+    if args.channels == 'auto':
+        for i in range(uut.nchannels):
+            fb = [0]*uut.nchannels
+            fb[i] = 0xffff;
+            uut.send_framebuf(fb)
+            time.sleep(0.2)
+            if bp.adc_value > 0.5:
+                break;
+        else:
+            raise ValueError('Cannot find active channel')
+        channels = [i]
+    else:
+        channels = list(parse_channels(args.channels))
+
+    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) ]
+    zero_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, zero_mean, stdev, time.time()))
+    print('Zero cal: {:5.4f}V stdev={:5.4f}V'.format(zero_mean, stdev))
+
+    for ch in channels:
+        for i in range(nbits):
+            fb = [0]*uut.nchannels
+            val = 1<<i
+            duty_cycle = val/(2**uut.nbits)
+            extra_shift = 16-uut.nbits
+            val <<= extra_shift
+
+            fb[ch] = val
+            uut.send_framebuf(fb)
+            
+            time.sleep(args.wait)
+            readings = [ bp.adc_value for _ in range(args.oversample) ]
+            mean, stdev = statistics.mean(readings), statistics.stdev(readings)
+
+            with db:
+                cur = db.cursor()
+                cur.execute('''
+                    INSERT INTO measurements (
+                            run_id, channel, duty_cycle, voltage, voltage_stdev, timestamp
+                        ) VALUES (?, ?, ?, ?, ?, ?)''',
+                        (run_id, ch, duty_cycle, mean, stdev, time.time()))
+                print('{:08d} ch={} {:04x}({:6.5f}): {:5.4f} stdev {:5.4f}'.format(
+                    cur.lastrowid, ch, val, duty_cycle, mean-zero_mean, stdev))
+
+    uut.send_framebuf([0]*uut.nchannels)
+    bp.power_on = False
+