Add additional lecture note companion scripts

Author: neil.hamilton

ps2000Examples/block_read.py

@@ -0,0 +1,115 @@
+from ctypes import byref, c_byte, c_int16, c_int32, sizeof
+from time import sleep
+
+from picosdk.ps2000 import ps2000
+from picosdk.functions import assert_pico2000_ok, adc2mV
+from picosdk.PicoDeviceEnums import picoEnum
+
+import matplotlib.pyplot as plt
+
+
+SAMPLES = 2000
+OVERSAMPLING = 1
+
+
+def get_timebase(device, wanted_time_interval):
+    current_timebase = 1
+
+    old_time_interval = None
+    time_interval = c_int32(0)
+    time_units = c_int16()
+    max_samples = c_int32()
+
+    while ps2000.ps2000_get_timebase(
+        device.handle,
+        current_timebase,
+        2000,
+        byref(time_interval),
+        byref(time_units),
+        1,
+        byref(max_samples)) == 0 \
+        or time_interval.value < wanted_time_interval:
+
+        current_timebase += 1
+        old_time_interval = time_interval.value
+
+        if current_timebase.bit_length() > sizeof(c_int16) * 8:
+            raise Exception('No appropriate timebase was identifiable')
+
+    return current_timebase - 1, old_time_interval
+
+
+with ps2000.open_unit() as device:
+    print('Device info: {}'.format(device.info))
+
+    res = ps2000.ps2000_set_channel(
+        device.handle,
+        picoEnum.PICO_CHANNEL['PICO_CHANNEL_A'],
+        True,
+        picoEnum.PICO_COUPLING['PICO_DC'],
+        ps2000.PS2000_VOLTAGE_RANGE['PS2000_500MV'],
+    )
+    assert_pico2000_ok(res)
+
+    res = ps2000.ps2000_set_channel(
+        device.handle,
+        picoEnum.PICO_CHANNEL['PICO_CHANNEL_B'],
+        True,
+        picoEnum.PICO_COUPLING['PICO_DC'],
+        ps2000.PS2000_VOLTAGE_RANGE['PS2000_50MV'],
+    )
+    assert_pico2000_ok(res)
+
+    timebase_a, interval = get_timebase(device, 4_000)
+
+    collection_time = c_int32()
+
+    res = ps2000.ps2000_run_block(
+        device.handle,
+        SAMPLES,
+        timebase_a,
+        OVERSAMPLING,
+        byref(collection_time)
+    )
+    assert_pico2000_ok(res)
+
+    while ps2000.ps2000_ready(device.handle) == 0:
+        sleep(0.1)
+
+    times = (c_int32 * SAMPLES)()
+
+    buffer_a = (c_int16 * SAMPLES)()
+    buffer_b = (c_int16 * SAMPLES)()
+
+    overflow = c_byte(0)
+
+    res = ps2000.ps2000_get_times_and_values(
+        device.handle,
+        byref(times),
+        byref(buffer_a),
+        byref(buffer_b),
+        None,
+        None,
+        byref(overflow),
+        2,
+        SAMPLES,
+    )
+    assert_pico2000_ok(res)
+
+    channel_a_overflow = (overflow.value & 0b0000_0001) != 0
+
+    ps2000.ps2000_stop(device.handle)
+
+    channel_a_mv = adc2mV(buffer_a, ps2000.PS2000_VOLTAGE_RANGE['PS2000_500MV'], c_int16(32767))
+    channel_b_mv = adc2mV(buffer_b, ps2000.PS2000_VOLTAGE_RANGE['PS2000_50MV'], c_int16(32767))
+
+    fig, ax = plt.subplots()
+    ax.set_xlabel('time/ms')
+    ax.set_ylabel('voltage/mV')
+    ax.plot(list(map(lambda x: x * 1e-6, times[:])), channel_a_mv[:])
+    ax.plot(list(map(lambda x: x * 1e-6, times[:])), channel_b_mv[:])
+
+    if channel_a_overflow:
+        ax.text(0.01, 0.01, 'Overflow present', color='red', transform=ax.transAxes)
+
+    plt.show()

ps2000Examples/device_info.py

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+from picosdk.ps2000 import ps2000
+
+with ps2000.open_unit() as device:
+    print('Device info: {}'.format(device.info))