renamed to m-teng

.gitignore

@@ -1,2 +1,3 @@
 __pycache__
 .ipynb_checkpoints
+testing

MANIFEST.in

@@ -0,0 +1,2 @@
+include regina/package-data/*
+include regina/sql/*.sql

bspc_rule.sh

@@ -0,0 +1 @@
+bspc rule -a matplotlib desktop=^1 state=pseudo_tiled focus=off

k-teng/keithley/measure.py

@@ -1,107 +0,0 @@
-from time import sleep
-import numpy as np
-from matplotlib import pyplot as plt
-import pyvisa
-
-from .keithley import reset
-from ..utility import testing as _testing
-
-def measure_count(instr, V=True, I=True, count=100, interval=0.05, update_func=None, update_interval=0.5, beep_done=True, verbose=True, testing=False):
-    """
-    Take <count> measurements with <interval> inbetween
-
-    @details
-        Uses the devices overlappedY function to make the measurements asynchronosly
-        The update_func is optional and only used when I == True and V == True
-        The update_func does not necessarily get all the values that are measured. To obtain the whole measurement, get them from the device buffers (smua.nvbufferX)
-    @param instr: pyvisa instrument
-    @param update_func: Callable that processes the measurements: (index, ival, vval) -> None
-    @param update_interval: interval at which the update_func is called
-    """
-    f_meas = None
-    if V and I:
-        f_meas = "smua.measure.overlappediv(smua.nvbuffer1, smua.nvbuffer2)"
-    elif V:
-        f_meas = "smua.measure.overlappedv(smua.nvbuffer1)"
-    elif I:
-        f_meas = "smua.measure.overlappedi(smua.nvbuffer1)"
-    else:
-        print("I and/or V needs to be set to True")
-        return
-
-    i = 0
-    if not testing:
-        reset(instr, verbose=verbose)
-        instr.write(f"smua.measure.count = {count}")
-        instr.write(f"smua.measure.interval = {interval}")
-
-        # start measurement
-        instr.write(f"smua.source.output = smua.OUTPUT_ON")
-        instr.write(f_meas)
-
-        condition = lambda: float(instr.query("print(status.operation.measuring.condition)").strip("\n ")) != 0
-    else:
-        condition = lambda: i < int(float(count) * interval / update_interval)
-
-    sleep(update_interval)
-    # for live viewing
-
-    query = """if smua.nvbufferX.n > 0 then print(smua.nvbufferX.readings[smua.nvbufferX.n]) else print(0) end"""
-    # will return 2.0 while measruing
-    while condition():
-        if update_func and V and I:
-            try:
-                if not testing:
-                    ival = float(instr.query(query.replace("X", "1")).strip("\n"))
-                    vval = float(instr.query(query.replace("X", "2")).strip("\n"))
-                else:
-                    ival = _testing.testcurve(i, peak_width=1, amplitude=5e-8)
-                    vval = -_testing.testcurve(i, peak_width=2, amplitude=15)
-                update_func(i, ival, vval)
-            except ValueError:
-                pass
-        sleep(update_interval)
-        i += 1
-
-    if not testing:
-        instr.write(f"smua.source.output = smua.OUTPUT_OFF")
-
-        if beep_done:
-            instr.write("beeper.beep(0.3, 1000)")
-
-
-def measure(instr, interval, update_func=None, max_measurements=None, testing=False):
-    """
-    @details:
-        - Resets the buffers
-        - Until KeyboardInterrupt:
-            - Take measurement
-            - Call update_func
-            - Wait interval
-        Uses python's time.sleep() for waiting the interval, which is not very precise. Use measure_count for better precision
-        You can take the data from the buffer afterwards, using save_csv
-    @param instr: pyvisa instrument
-    @param update_func: Callable that processes the measurements: (index, ival, vval) -> None
-    @param max_measurements : maximum number of measurements. None means infinite
-    """
-    if not testing:
-        reset(instr, verbose=True)
-        instr.write("smua.source.output = smua.OUTPUT_ON")
-        instr.write("format.data = format.ASCII\nformat.asciiprecision = 12")
-    try:
-        i = 0
-        while max_measurements is None or i < max_measurements:
-            if testing:
-                ival = _testing.testcurve(i, peak_width=1, amplitude=5e-8)
-                vval = -_testing.testcurve(i, peak_width=2, amplitude=15)
-            else:
-                ival, vval = tuple(float(v) for v in instr.query("print(smua.measure.iv(smua.nvbuffer1, smua.nvbuffer2))").strip('\n').split('\t'))
-            if update_func:
-                update_func(i, ival, vval)
-            sleep(interval)
-            i += 1
-    except KeyboardInterrupt:
-        pass
-    if not testing:
-        instr.write("smua.source.output = smua.OUTPUT_OFF")
-    print("Measurement stopped" + " "*50)

k-teng/materials

@@ -1,4 +0,0 @@
-pdms
-kapton
-plastic
-

k-teng/test.py

@@ -1,49 +0,0 @@
-readings = [
-  4.974127e-10, -1.418591e-12, -1.573563e-12, -1.728535e-12, -1.704693e-12,
- -1.847744e-12, -1.931190e-12, -1.788139e-12, -1.871586e-12, -2.169609e-12,
- -2.074242e-12, -1.895428e-12, -1.895428e-12, -1.776218e-12, -1.990795e-12,
- -1.788139e-12, -1.811981e-12, -1.657009e-12, -1.573563e-12, -2.396107e-12,
- -2.515316e-12, -2.765656e-12, -2.825260e-12, -3.147125e-12, -2.300739e-12,
- -2.825260e-12, -3.278255e-12, -5.257130e-12, -6.818771e-12, -8.916855e-12,
- -7.712841e-12,  6.437302e-12, -1.142025e-11, -1.206398e-11, -4.649043e-10,
- -3.427613e-09, -2.460408e-09, -2.340376e-09, -1.306653e-10,  1.496077e-11,
-  2.933741e-11,  1.953280e-09,  8.579970e-10,  9.226799e-12, -1.095533e-11,
- -2.508163e-11, -2.776039e-09, -8.686423e-09,  4.935264e-12,  1.246929e-11,
-  3.225744e-09,  2.814472e-09,  1.877034e-09,  2.229273e-09,  1.713574e-09,
-  8.355618e-10, -4.332781e-10,  5.896091e-11,  5.762577e-11,  8.129537e-09,
-  4.044378e-09,  1.771629e-09,  7.849216e-10,  4.098892e-10,  3.390551e-10,
-  2.956390e-10,  3.033876e-10,  1.716256e-10,  1.463890e-11, -5.078316e-12,
- -6.949902e-12, -8.106232e-12, -6.473065e-12, -4.506111e-12,  4.919767e-11,
-  3.052297e-08,  1.161162e-08, -9.892106e-09, -3.613818e-09, -5.004287e-09,
- -2.015829e-11, -4.183054e-11, -1.810908e-10, -2.042532e-10, -3.516316e-10,
-  5.099773e-11,  1.921976e-08, -1.256589e-08, -4.242897e-10, -1.358986e-12,
- -3.445148e-12, -3.838539e-12, -4.184246e-12, -7.402897e-12, -2.840877e-10,
- -2.872229e-10, -2.730966e-10, -1.134396e-10, -4.376173e-11, -3.576279e-14
-]
-timestamps = [
- 0.      , 0.05    , 0.1     , 0.15,     0.2,      0.25,     0.3,      0.35,
- 0.4     , 0.45    , 0.5     , 0.55,     0.6,      0.65,     0.7,      0.75,
- 0.8     , 0.85    , 0.9     , 0.95,     1. ,      1.05,     1.1,      1.15,
- 1.2     , 1.25    , 1.3     , 1.35,     1.4,      1.45,     1.5,      1.55,
- 1.6     , 1.690891, 1.710923, 1.75,     1.8,      1.85,     1.9,      1.95,
- 2.      , 2.05    , 2.1     , 2.15,     2.2,      2.25,     2.3,      2.35,
- 2.420332, 2.45    , 2.5     , 2.55,     2.6,      2.65,     2.7,      2.75,
- 2.820553, 2.890843, 2.910875, 2.95,     3. ,      3.05,     3.1,      3.15,
- 3.2     , 3.25    , 3.3     , 3.35,     3.4,      3.45,     3.5,      3.55,
- 3.6     , 3.65    , 3.7     , 3.75,     3.8,      3.85,     3.9,      3.95,
- 4.      , 4.05    , 4.1     , 4.15,     4.2,      4.25,     4.3,      4.35,
- 4.4     , 4.45    , 4.5     , 4.55,     4.6,      4.65,     4.7,      4.75,
- 4.8     , 4.85    , 4.9     , 4.95,    ]
-
-import pandas as pd
-import numpy as np
-import scipy as sp
-import matplotlib.pyplot as plt
-df = pd.DataFrame(np.vstack((timestamps, readings)).T)
-df.columns = ["Time [s]", "Voltage [V]"]
-print(df)
-df.to_csv("test.csv", sep=",", header=True, index=False)
-
-df.plot(x='Time [s]', y="Voltage [V]")
-plt.show()
-

k-teng/testcurve.py

@@ -1,33 +0,0 @@
-import numpy as np
-import matplotlib.pyplot as plt
-
-def testcurve(x, frequency=10, peak_width=2, amplitude=20, bias=0):
-    # want peak at n*time == frequency
-    nearest_peak = np.round(x / frequency, 0)
-    # if not peak at 0 and within peak_width
-    # print(x, nearest_peak)
-    if nearest_peak > 0 and abs((x - nearest_peak * frequency)) < peak_width:
-        # return sin that does one period within 2*peak_width
-        return amplitude * np.sin(2*np.pi * (x - nearest_peak * frequency - peak_width) / (2*peak_width)) + bias
-    else:
-        return bias
-
-    # 0 = pk - width
-    # 2pi = pk + width
-
-def baseline(data):
-    # find the value where the most values with low gradients are closest to
-    gradients = np.abs(np.gradient(data))
-    # consider the values where the absolute gradient is in the bottom 20%
-    n_gradients = len(data) // 20
-    consider_indices = np.argsort(gradients)[:n_gradients]
-    # of those, only consider values where the value 
-    consider_values = data[consider_indices]
-
-
-xdata = np.arange(0, 100, 0.01)
-ydata = np.vectorize(testcurve)(xdata)
-
-
-plt.plot(xdata, ydata)
-plt.show()

k-teng/utility/testing.py

@@ -1,38 +0,0 @@
-
-import pandas as pd
-import numpy as np
-
-def collect_buffer(instr, buffer_nr=1):
-    """
-    Get the buffer as 2D - np.array
-    @param instr : pyvisa instrument
-    @param buffer_nr : 1 or 2, for smua.nvbuffer1 or 2
-    @returns 2D numpy array:
-        i - ith reading:
-            0: timestamps
-            1: readings
-    """
-    if buffer_nr == 2: buffername = "smua.nvbuffer2"
-    else: buffername = "smua.nvbuffer1"
-    # instr.write("format.data = format.DREAL\nformat.byteorder = format.LITTLEENDIAN")
-    # buffer = instr.query_binary_values(f"printbuffer(1, {buffername}.n, {buffername})", datatype='d', container=np.array)
-    instr.write("format.data = format.ASCII\nformat.asciiprecision = 7")
-    timestamps = instr.query_ascii_values(f"printbuffer(1, {buffername}.n, {buffername}.timestamps)", container=np.array)
-    readings = instr.query_ascii_values(f"printbuffer(1, {buffername}.n, {buffername}.readings)", container=np.array)
-    print(f"readings: {readings}, \ntimestamps: {timestamps}")
-    buffer = np.vstack((timestamps, readings)).T
-    return buffer
-
-
-def testcurve(x, frequency=10, peak_width=2, amplitude=20, bias=0):
-    # want peak at n*time == frequency
-    nearest_peak = np.round(x / frequency, 0)
-    # if not peak at 0 and within peak_width
-    if nearest_peak > 0 and abs((x - nearest_peak * frequency)) < peak_width:
-        # return sin that does one period within 2*peak_width
-        return amplitude * np.sin(2*np.pi * (x - nearest_peak * frequency - peak_width) / (2*peak_width)) + bias
-    else:
-        return bias
-
-    # 0 = pk - width
-    # 2pi = pk + width

m_teng/backends/arduino/arduino.py

@@ -0,0 +1,123 @@
+import bleak as b
+import asyncio
+import numpy as np
+
+TARGET_NAME = "ArduinoTENG"
+
+# GATT service and characteristics UUIDs
+TENG_SUUID          = "00010000-9a74-4b30-9361-4a16ec09930f"
+TENG_STATUS_CUUID   = "00010001-9a74-4b30-9361-4a16ec09930f"
+TENG_COMMAND_CUUID  = "00010002-9a74-4b30-9361-4a16ec09930f"
+TENG_READING_CUUID  = "00010003-9a74-4b30-9361-4a16ec09930f"
+TENG_SETTING_INTERVAL_CUUID = "00010004-9a74-4b30-9361-4a16ec09930f"
+
+TENG_COMMANDS = {
+    "NOOP":             int(0).to_bytes(1),
+    "MEASURE_BASELINE": int(1).to_bytes(1),
+}
+TENG_STATUS = ["ERROR", "BUSY", "WAIT_CONNECT", "MEASURING_BASELINE", "READING"]
+
+# TODO save measurements on device buffer, transfer later
+
+
+# wrapper for global variable
+class Buffer:
+    def __init__(self):
+        self.data = None
+_buffer = Buffer()
+
+def teng_status_callback(characteristic, data):
+    value = int.from_bytes(data, byteorder="big", signed=False)
+    if 0 <= value and value < len(TENG_STATUS):
+        print(f"Status change: {TENG_STATUS[value]}")
+    else:
+        print(f"Status change (invalid): status={value}")
+
+
+def disconnect_callback(client):
+    raise Exception(f"The bluetooth device {client.name} was disconnected")
+
+
+async def init_arduino_async(n_tries: int=5) -> b.BleakClient:
+    n_try = 0
+    if n_tries <= 0: n_tries = "inf"
+    try:
+        target_device = None
+        while target_device is None and (n_tries == "inf" or n_try < n_tries):
+            print(f"Searching for bluetooth device '{TARGET_NAME}' ({n_try}/{n_tries})", end="\r")
+            devices = await b.BleakScanner.discover(return_adv=True)
+            # print(devices)
+            for adr, (device, adv_data) in devices.items():
+                if device.name == TARGET_NAME:
+                    # print(adv_data)
+                    target_device = device
+                    break
+            n_try += 1
+        if target_device is None:
+            raise Exception(f"Could not find bluetooth device 'ArduinoTENG'")
+        # print(f"Found target device: {target_device.name}: {target_device.metadata}, {target_device.details}")
+        # print(target_device.name, target_device.details)
+        client = b.BleakClient(target_device, disconnect_callback=disconnect_callback)
+        return client
+    except asyncio.exceptions.CancelledError:
+        raise Exception(f"Cancelled")
+
+
+def init(beep_success=True, n_tries: int=5) -> b.BleakClient:
+    """
+    Connect to the arduino
+    @returns: BleakClient
+    """
+    client = asyncio.run(init_arduino_async(n_tries=n_tries))
+    if beep_success: beep(client)
+    return client
+
+
+def set_interval(client, interval: float):
+    """
+    Set the measurement interval
+    @param interval: interval in seconds
+    """
+    interval = int(interval * 1000)  # convert to ms for arduinos delay)
+    await client.write_gatt_char(TENG_SETTING_INTERVAL_CUUID, interval.to_bytes(2, byteorder=LITTLEENDIAN, signed=False))
+
+
+# async def main():
+#             for service in client.services:
+#                 print(f"Service: {service.uuid}: {service.description}")
+#                 for c in service.characteristics:
+#                     print(f"\t{c.uuid}: {c.properties}, {c.descriptors}")
+#             teng_status     = client.services.get_characteristic(TENG_STATUS_CUUID)
+#             teng_command    = client.services.get_characteristic(TENG_COMMAND_CUUID)
+#             teng_reading    = client.services.get_characteristic(TENG_READING_CUUID)
+#             client.start_notify(teng_status, teng_status_callback)
+
+#             await client.write_gatt_char(teng_command, TENG_COMMANDS["NOOP"])
+#             await asyncio.sleep(5)
+#             await client.write_gatt_char(teng_command, TENG_COMMANDS["MEASURE_BASELINE"])
+
+#             while client.is_connected:
+#                 data = await client.read_gatt_char(teng_reading)
+
+
+#                 value = int.from_bytes(data, byteorder="little", signed=False)
+#                 print(f"Reading: {value}")
+#                 await asyncio.sleep(0.5)
+#     except KeyboardInterrupt:
+#         pass
+#     except asyncio.exceptions.CancelledError:
+#         pass
+#     print("Disconnected")
+
+
+def collect_buffer(instr, buffer_nr=1):
+    """
+    @param buffer_nr: 1 -> current, 2 -> voltage
+    """
+    assert(buffer_nr in (1, 2))
+    return np.vstack((_buffer.data[:,0], _buffer._data[:,buffer_nr])).T
+
+
+def beep(client):
+    # TODO connect beeper to arduino?
+    print(beep)

m_teng/backends/arduino/measure.py

@@ -0,0 +1,59 @@
+import bleak as b
+import numpy as np
+
+import asyncio
+import datetime
+
+from .arduino.arduino import beep, set_interval, TENG_READING_CUUID, _buffer
+
+
+# equivalent to internal keithley buffer: write to this value and collect afterwards
+
+def measure_count(client, count=100, interval=0.05, update_func=None, update_interval=0.5, beep_done=True, verbose=True, testing=False):
+    global _buffer
+    _buffer.data = np.zeros((count, 3))
+    i = 0
+    t_start = datetime.datetime.now()
+
+    async def add_buffer.data(client):
+        if i >= count: return
+        _buffer.data[i][0] = float((datetime.datetime.now() - t_start).microseconds) / 1000
+        reading = await client.read_gatt_char(TENG_READING_CUUID)
+        _buffer.data[i][2] = int.from_bytes(reading, byteorder=LITTLEENDIAN, signed=False).
+        i += 1
+
+    set_interval(client, interval)
+    # TODO check if notify works when the same value is written again
+    client.start_notify(TENG_READING_CUUID, add_buffer.data)
+    while i < count:
+        asyncio.sleep(update_interval)
+        if update_func is not None:  # assume an update has occured
+            update_func(i, 0, _buffer.data[i, 2])
+    if beep_done: beep(client)
+
+
+def measure(client, interval, update_func=None, max_measurements=None, testing=False):
+    global _buffer
+    _buffer.data = np.zeros((count, 3))
+    i = 0
+    t_start = datetime.datetime.now()
+
+    async def add_buffer.data(client):
+        if i >= count: return
+        _buffer.data[i][0] = datetime.datetime.now() - t_start
+        vval = await client.read_gatt_char(TENG_READING_CUUID)
+        vval = int.from_bytes(reading, byteorder=LITTLEENDIAN, signed=False).
+        _buffer.data[i][2] = vval
+        if update_func:
+            update_func(i, 0, vval)
+        i += 1
+
+    set_interval(client, interval)
+    client.start_notify(TENG_READING_CUUID, add_buffer.data)
+    try:
+        while max_measurements is None or i < max_measurements:
+            asyncio.sleep(interval / 2)  # 
+    except asyncio.exceptions.CancelledError:
+        pass
+    print("Measurement stopped" + " "*50)
+

m_teng/backends/keithley/keithley.py

@@ -1,20 +1,19 @@
 import pyvisa
 import numpy as np
+import pkg_resources
 
 
 """
 Utility
 """
-script_dir = "../scripts/"
+
 scripts = {
-    "buffer_reset":     "buffer_reset.lua",
+    "buffer_reset": pkg_resources.resource_filename("m_teng", "keithley_scripts/buffer_reset.lua"),
-    "smua_reset":       "smua_reset.lua",
+    "smua_reset":   pkg_resources.resource_filename("m_teng", "keithley_scripts/smua_reset.lua"),
 }
-for key,val in scripts.items():
-    scripts[key] = script_dir + scripts[key]
 
 
-def init_keithley(beep_success=True):
+def init(beep_success=True):
     rm = pyvisa.ResourceManager('@py')
     resources = rm.list_resources()
     if len(resources) < 1:
@@ -52,6 +51,15 @@ def reset(instr, verbose=False):
     run_lua(instr, scripts["smua_reset"], verbose=verbose)
     run_lua(instr, scripts["buffer_reset"], verbose=verbose)
 
+def get_buffer_name(buffer_nr: int):
+    if buffer_nr == 2: return "smua.nvbuffer2"
+    elif buffer_nr == 1:  return "smua.nvbuffer1"
+    raise ValueError(f"Invalid buffer_nr: {buffer_nr}")
+
+def get_buffer_size(instr, buffer_nr=1):
+    n = instr.query(f"print({get_buffer_name(buffer_nr)}.n)").strip("\n")
+    return int(float(n))
+
 
 def collect_buffer(instr, buffer_nr=1, verbose=False):
     """
@@ -63,8 +71,7 @@ def collect_buffer(instr, buffer_nr=1, verbose=False):
             0: timestamps
             1: readings
     """
-    if buffer_nr == 2: buffername = "smua.nvbuffer2"
+    buffername = get_buffer_name(buffer_nr)
-    else: buffername = "smua.nvbuffer1"
     # instr.write("format.data = format.DREAL\nformat.byteorder = format.LITTLEENDIAN")
     # buffer = instr.query_binary_values(f"printbuffer(1, {buffername}.n, {buffername})", datatype='d', container=np.array)
     instr.write("format.data = format.ASCII\nformat.asciiprecision = 7")
@@ -75,3 +82,30 @@ def collect_buffer(instr, buffer_nr=1, verbose=False):
     buffer = np.vstack((timestamps, readings)).T
     return buffer
 
+
+
+def collect_buffer_range(instr, range_=(1, -1), buffer_nr=1, verbose=False):
+    """
+    Get the buffer as 2D - np.array
+    @param instr : pyvisa instrument
+    @param buffer_nr : 1 or 2, for smua.nvbuffer1 or 2
+    @returns 2D numpy array:
+        i - ith reading:
+            0: timestamps
+            1: readings
+    """
+    buffername = get_buffer_name(buffer_nr)
+    # instr.write("format.data = format.DREAL\nformat.byteorder = format.LITTLEENDIAN")
+    # buffer = instr.query_binary_values(f"printbuffer(1, {buffername}.n, {buffername})", datatype='d', container=np.array)
+    if range_[1] == -1:
+        range_ = (range_[0], f"{buffername}.n")
+    instr.write("format.data = format.ASCII\nformat.asciiprecision = 7")
+    timestamps = instr.query_ascii_values(f"printbuffer({range_[0]}, {range_[1]}, {buffername}.timestamps)", container=np.array)
+    readings = instr.query_ascii_values(f"printbuffer({range_[0]}, {range_[1]}, {buffername}.readings)", container=np.array)
+    if verbose:
+        print(f"readings from {buffername}: {readings}, \ntimestamps: {timestamps}")
+    buffer = np.vstack((timestamps, readings)).T
+    return buffer
+
+
+

m_teng/backends/keithley/measure.py

@@ -0,0 +1,93 @@
+from time import sleep
+import numpy as np
+from matplotlib import pyplot as plt
+import pyvisa
+
+from .keithley import reset
+from ..utility import testing as _testing
+
+def measure_count(instr, count=100, interval=0.05, update_func=None, update_interval=0.5, beep_done=True, verbose=True):
+    """
+    Take <count> measurements with <interval> inbetween
+
+    @details
+        Uses the devices overlappedY function to make the measurements asynchronosly
+        The update_func is optional and only used when I == True and V == True
+        The update_func does not necessarily get all the values that are measured. To obtain the whole measurement, get them from the device buffers (smua.nvbufferX)
+    @param instr: pyvisa instrument
+    @param update_func: Callable that processes the measurements: (index, ival, vval) -> None
+    @param update_interval: interval at which the update_func is called
+    """
+    f_meas = "smua.measure.overlappediv(smua.nvbuffer1, smua.nvbuffer2)"
+    # if V and I:
+    # elif V:
+    #     f_meas = "smua.measure.overlappedv(smua.nvbuffer1)"
+    # elif I:
+    #     f_meas = "smua.measure.overlappedi(smua.nvbuffer1)"
+    # else:
+    #     print("I and/or V needs to be set to True")
+    #     return
+
+    i = 0
+    reset(instr, verbose=verbose)
+    instr.write(f"smua.measure.count = {count}")
+    instr.write(f"smua.measure.interval = {interval}")
+
+    # start measurement
+    instr.write(f"smua.source.output = smua.OUTPUT_ON")
+    instr.write(f_meas)
+
+    sleep(update_interval)
+    # for live viewing
+    query = """if smua.nvbufferX.n > 0 then print(smua.nvbufferX.readings[smua.nvbufferX.n]) else print(0) end"""
+
+    # will return 2.0 while measruing
+    while float(instr.query("print(status.operation.measuring.condition)").strip("\n ")) != 0:
+        if update_func:
+            try:
+                ival = float(instr.query(query.replace("X", "1")).strip("\n"))
+                vval = float(instr.query(query.replace("X", "2")).strip("\n"))
+                update_func(i, ival, vval)
+            except ValueError as e:
+                if i != 0:
+                    pass
+                else:
+                    print(f"measure_count: ValueError: {e}")
+        sleep(update_interval)
+        i += 1
+
+    instr.write(f"smua.source.output = smua.OUTPUT_OFF")
+
+    if beep_done:
+        instr.write("beeper.beep(0.3, 1000)")
+
+
+def measure(instr, interval, update_func=None, max_measurements=None):
+    """
+    @details:
+        - Resets the buffers
+        - Until KeyboardInterrupt:
+            - Take measurement
+            - Call update_func
+            - Wait interval
+        Uses python's time.sleep() for waiting the interval, which is not very precise. Use measure_count for better precision
+        You can take the data from the buffer afterwards, using save_csv
+    @param instr: pyvisa instrument
+    @param update_func: Callable that processes the measurements: (index, ival, vval) -> None
+    @param max_measurements : maximum number of measurements. None means infinite
+    """
+    reset(instr, verbose=True)
+    instr.write("smua.source.output = smua.OUTPUT_ON")
+    instr.write("format.data = format.ASCII\nformat.asciiprecision = 12")
+    try:
+        i = 0
+        while max_measurements is None or i < max_measurements:
+            ival, vval = tuple(float(v) for v in instr.query("print(smua.measure.iv(smua.nvbuffer1, smua.nvbuffer2))").strip('\n').split('\t'))
+            if update_func:
+                update_func(i, ival, vval)
+            sleep(interval)
+            i += 1
+    except KeyboardInterrupt:
+        pass
+    instr.write("smua.source.output = smua.OUTPUT_OFF")
+    print("Measurement stopped" + " "*50)

m_teng/m_teng_interactive.py

@@ -1,6 +1,6 @@
 """
 run this before using this library:
-ipython -i k_teng_interactive.py
+ipython -i m_teng_interactive.py
 
 always records iv-t curves
     i-data -> smua.nvbuffer1
@@ -18,21 +18,54 @@ from os import path, makedirs
 import pickle as pkl
 import json
 
+import argparse
+
+
 if __name__ == "__main__":
+    import sys
     if __package__ is None:
         # make relative imports work as described here: https://peps.python.org/pep-0366/#proposed-change
-        __package__ = "k-teng"
+        __package__ = "m_teng"
-        import sys
         from os import path
         filepath = path.realpath(path.abspath(__file__))
         sys.path.insert(0, path.dirname(path.dirname(filepath)))
+    parser = argparse.ArgumentParser(
+        prog="m-teng",
+        description="measure triboelectric nanogenerator output using a Keithley SMU or an Arduino",
+    )
+    backend_group = parser.add_mutually_exclusive_group(required=True)
+    backend_group.add_argument("-k", "--keithley", action="store_true")
+    backend_group.add_argument("-a", "--arduino", action="store_true")
+    backend_group.add_argument("-t", "--testing", action='store_true')
+    parser.add_argument("-c", "--config", action="store", help="alternate path to config file")
+    args = vars(parser.parse_args())
+
+    i = 1
+    while i < len(sys.argv):
+        if args["keithley"]:
+            import m_teng.backends.keithley.keithley as _backend
+            import m_teng.backends.keithley.measure as _measure
+        elif args["arduino"]:
+            import m_teng.backends.arduino.arduino as _backend
+            import m_teng.backends.arduino.measure as _measure
+        elif args["testing"]:
+            import m_teng.backends.testing.testing as _backend
+            import m_teng.backends.testing.measure as _measure
+        elif sys.argv[i] in ["-c", "--config"]:
+            if i+1 < len(sys.argv):
+                config_path = sys.argv[i+1]
+            else:
+                print("-c requires an extra argument: path of config file")
+            i += 1
+        i += 1
 
 
-from .keithley import keithley as _keithley
+from m_teng.utility import data as _data
-from .keithley.measure import measure_count as _measure_count, measure as _measure
+from m_teng.utility.data import load_dataframe
-from .utility import data as _data
+from m_teng.utility import file_io
-from .utility.data import load_dataframe
+from m_teng.update_funcs import _Monitor, _ModelPredict, _update_print
-from .utility import file_io
+
+config_path = path.expanduser("~/.config/k-teng.json")
 
 _runtime_vars = {
     "last-measurement": ""
@@ -44,66 +77,35 @@ settings = {
     "interval":     0.02,
     "beep":         True,
 }
-config_path = path.expanduser("~/.config/k-teng.json")
 
 test = False
 
-# global variable for the instrument returned by pyvisa
+# global variable for the instrument/client returned by pyvisa/bleak
-k = None
+dev = None
 
 
-
+def monitor_predict(model_dir: str, count=5000, interval=settings["interval"], max_points_shown=160):
-def _update_print(i, ival, vval):
-    print(f"n = {i:5d}, I = {ival: .12f} A, U = {vval: .5f} V" + " "*10, end='\r')
-
-class _Monitor:
     """
-    Monitor v and i data
+    Take <count> measurements in <interval> and predict with a machine learning model
     """
-    def __init__(self, max_points_shown=None, use_print=False):
+    model_predict = _ModelPredict(dev, model_dir)
-        self.max_points_shown = max_points_shown
+    plt_monitor = _Monitor(max_points_shown, use_print=False)
-        self.use_print = use_print
+    skip_n = 0
-        self.index = []
+    def update(i, ival, vval):
-        self.vdata = []
+        plt_monitor.update(i, ival, vval)
-        self.idata = []
+        if skip_n % 10 == 0:
-
+            model_predict.update(i, ival, vval)
-        plt.ion()
+        skip_n += 1
-        self.fig1, (self.vax, self.iax) = plt.subplots(2, 1, figsize=(8, 5))
-
-        self.vline,  = self.vax.plot(self.index, self.vdata, color="g")
-        self.vax.set_ylabel("Voltage [V]")
-        self.vax.grid(True)
-
-        self.iline,  = self.iax.plot(self.index, self.idata, color="m")
-        self.iax.set_ylabel("Current [A]")
-        self.iax.grid(True)
-
-    def update(self, i, ival, vval):
-        if self.use_print:
-            _update_print(i, ival, vval)
-        self.index.append(i)
-        self.idata.append(ival)
-        self.vdata.append(vval)
-        # update data
-        self.iline.set_xdata(self.index)
-        self.iline.set_ydata(self.idata)
-        self.vline.set_xdata(self.index)
-        self.vline.set_ydata(self.vdata)
-        # recalculate limits and set them for the view
-        self.iax.relim()
-        self.vax.relim()
-        if self.max_points_shown and i > self.max_points_shown:
-            self.iax.set_xlim(i - self.max_points_shown, i)
-            self.vax.set_xlim(i - self.max_points_shown, i)
-        self.iax.autoscale_view()
-        self.vax.autoscale_view()
-        # update plot
-        self.fig1.canvas.draw()
-        self.fig1.canvas.flush_events()
-
-    def __del__(self):
-        plt.close(self.fig1)
 
+    print(f"Starting measurement with:\n\tinterval = {interval}s\nSave the data using 'save_csv()' afterwards.")
+    try:
+        _measure.measure_count(dev, V=True, I=True, count=count, interval=interval, beep_done=False, verbose=False, update_func=update, update_interval=0.1)
+    except KeyboardInterrupt:
+        if args["keithley"]:
+            dev.write(f"smua.source.output = smua.OUTPUT_OFF")
+        print("Monitoring cancelled, measurement might still continue" + " "*50)
+    else:
+        print("Measurement finished" + " "*50)
 
 def monitor_count(count=5000, interval=settings["interval"], max_points_shown=160):
     """
@@ -123,10 +125,10 @@ def monitor_count(count=5000, interval=settings["interval"], max_points_shown=16
 
     print(f"Starting measurement with:\n\tinterval = {interval}s\nSave the data using 'save_csv()' afterwards.")
     try:
-        _measure_count(k, V=True, I=True, count=count, interval=interval, beep_done=False, verbose=False, update_func=update_func, update_interval=0.05, testing=test)
+        _measure.measure_count(dev, V=True, I=True, count=count, interval=interval, beep_done=False, verbose=False, update_func=update_func, update_interval=0.05)
     except KeyboardInterrupt:
-        if not test:
+        if args["keithley"]:
-            k.write(f"smua.source.output = smua.OUTPUT_OFF")
+            dev.write(f"smua.source.output = smua.OUTPUT_OFF")
         print("Monitoring cancelled, measurement might still continue" + " "*50)
     else:
         print("Measurement finished" + " "*50)
@@ -147,10 +149,10 @@ def measure_count(count=5000, interval=settings["interval"]):
 
     print(f"Starting measurement with:\n\tinterval = {interval}s\nSave the data using 'save_csv()' afterwards.")
     try:
-        _measure_count(k, V=True, I=True, count=count, interval=interval, beep_done=False, verbose=False, update_func=update_func, update_interval=0.05, testing=test)
+        _measure.measure_count(dev, count=count, interval=interval, beep_done=False, verbose=False, update_func=update_func, update_interval=0.05)
     except KeyboardInterrupt:
-        if not test:
+        if args["keithley"]:
-            k.write(f"smua.source.output = smua.OUTPUT_OFF")
+            dev.write(f"smua.source.output = smua.OUTPUT_OFF")
         print("Monitoring cancelled, measurement might still continue" + " "*50)
     else:
         print("Measurement finished" + " "*50)
@@ -176,7 +178,7 @@ def monitor(interval=settings["interval"], max_measurements=None, max_points_sho
     print(f"Starting measurement with:\n\tinterval = {interval}s\nUse <C-c> to stop. Save the data using 'save_csv()' afterwards.")
     plt_monitor = _Monitor(use_print=True, max_points_shown=max_points_shown)
     update_func = plt_monitor.update
-    _measure(k, interval=interval, max_measurements=max_measurements, update_func=update_func, testing=test)
+    _measure.measure(dev, interval=interval, max_measurements=max_measurements, update_func=update_func)
 
 
 def measure(interval=settings["interval"], max_measurements=None):
@@ -195,7 +197,7 @@ def measure(interval=settings["interval"], max_measurements=None):
     _runtime_vars["last_measurement"] = dtime.now().isoformat()
     print(f"Starting measurement with:\n\tinterval = {interval}s\nUse <C-c> to stop. Save the data using 'save_csv()' afterwards.")
     update_func = _update_print
-    _measure(k, interval=interval, max_measurements=max_measurements, update_func=update_func, testing=test)
+    _measure.measure(dev, interval=interval, max_measurements=max_measurements, update_func=update_func)
 
 
 def repeat(measure_func: callable, count: int, repeat_delay=0):
@@ -221,7 +223,7 @@ def repeat(measure_func: callable, count: int, repeat_delay=0):
             sleep(repeat_delay)
     except KeyboardInterrupt:
         pass
-    if settings["beep"]: k.write("beeper.beep(0.3, 1000)")
+    if settings["beep"]: _backend.beep()
 
 
 def get_dataframe():
@@ -229,21 +231,14 @@ def get_dataframe():
     Get a pandas dataframe from the data in smua.nvbuffer1 and smua.nvbuffer2
     """
     global k, settings, _runtime_vars
-    if test:
+    ibuffer = _backend.collect_buffer(dev, 1)
-        timestamps = np.arange(0, 50, 0.01)
+    vbuffer = _backend.collect_buffer(dev, 2)
-        ydata = np.array([testing.testcurve(t, amplitude=15, peak_width=2) for t in timestamps])
-        ibuffer = np.vstack((timestamps, ydata)).T
-
-        ydata = np.array([-testing.testcurve(t, amplitude=5e-8, peak_width=1) for t in timestamps])
-        vbuffer = np.vstack((timestamps, ydata)).T
-    else:
-        ibuffer = _keithley.collect_buffer(k, 1)
-        vbuffer = _keithley.collect_buffer(k, 2)
     df = _data.buffers2dataframe(ibuffer, vbuffer)
     df.basename = file_io.get_next_filename(settings["name"], settings["datadir"])
     df.name = f"{df.basename} @ {_runtime_vars['last-measurement']}"
     return df
 
+
 def save_csv():
     """
     Saves the contents of nvbuffer1 as .csv
@@ -267,6 +262,7 @@ def save_pickle():
     df.to_pickle(filename)
     print(f"Saved as '{filename}'")
 
+
 def run_script(script_path):
     """
     Run a lua script on the Keithley device
@@ -276,7 +272,7 @@ def run_script(script_path):
     if test:
         print("run_script: Test mode enabled, ignoring call to run_script")
     else:
-        _keithley.run_lua(k, script_path=script_path)
+        _keithley.run_lua(dev, script_path=script_path)
 
 
 def set(setting, value):
@@ -333,13 +329,13 @@ Run 'help("topic")' to see more information on a topic""")
 Functions:
     name("<name>")         - short for set("name", "<name>")
     set("setting", value)  - set a setting to a value
-    save_settings()        - store the settings as "k-teng.conf" in the working directory
+    save_settings()        - store the settings as "m-teng.json" in the working directory
     load_settings()        - load settings from a file
     The global variable 'config_path' determines the path used by save/load_settings. Use -c '<path>' to set another path.
     The serach path is:
-        <working-dir>/k-teng.json
+        <working-dir>/m-teng.json
-        $XDG_CONFIG_HOME/k-teng.json
+        $XDG_CONFIG_HOME/m-teng.json
-        ~/.config/k-teng.json
+        ~/.config/m-teng.json
               """)
     elif topic == "imports":
         print("""Imports:
@@ -349,7 +345,7 @@ Functions:
     os.path """)
     elif topic == "device":
         print("""Device:
-    The opened pyvisa resource (Keithley device) is the global variable 'k'.
+    The opened pyvisa resource (deveithley device) is the global variable 'k'.
     You can interact using pyvisa functions, such as
     k.write("command"), k.query("command") etc. to interact with the device.""")
     else:
@@ -357,37 +353,26 @@ Functions:
 
 
 def init():
-    global k, settings, test, config_path
+    global dev, settings, config_path
-    print(r""" ____  __.         ______________________ _______     ________
+    print(r"""              ______________________ _______     ________
-|    |/ _|         \__    ___/\_   _____/ \      \   /  _____/
+  _____       \__    ___/\_   _____/ \      \   /  _____/
-|      <    ______   |    |    |    __)_  /   |   \ /   \  ___
+ /     \  ______|    |    |    __)_  /   |   \ /   \  ___
-|    |  \  /_____/   |    |    |        \/    |    \\    \_\  \
+|  Y Y  \/_____/|    |    |        \/    |    \\    \_\  \
-|____|__ \           |____|   /_______  /\____|__  / \______  /
+|__|_|  /       |____|   /_______  /\____|__  / \______  /
-        \/                            \/         \/         \/      1.1
+      \/                         \/         \/         \/   1.2
 Interactive Shell for TENG measurements with Keithley 2600B
 ---
 Enter 'help()' for a list of commands""")
     from os import environ
-    if path.isfile("k-teng.json"):
+    if path.isfile("m-teng.json"):
-        config_path = "k-teng.json"
+        config_path = "m-teng.json"
     elif 'XDG_CONFIG_HOME' in environ.keys():
-        # and path.isfile(environ["XDG_CONFIG_HOME"] + "/k-teng.json"):
+        # and path.isfile(environ["XDG_CONFIG_HOME"] + "/m-teng.json"):
-        config_path = environ["XDG_CONFIG_HOME"] + "/k-teng.json"
+        config_path = environ["XDG_CONFIG_HOME"] + "/m-teng.json"
     else:
-        config_path = path.expanduser("~/.config/k-teng.json")
+        config_path = path.expanduser("~/.config/m-teng.json")
-
+    if args["config"]:
-    from sys import argv
+        config_path = args["config"]
-    i = 1
-    while i < len(argv):
-        if argv[i] in ["-t", "--test"]:
-            test = True
-        elif argv[i] in ["-c", "--config"]:
-            if i+1 < len(argv):
-                config_path = argv[i+1]
-            else:
-                print("-c requires an extra argument: path of config file")
-            i += 1
-        i += 1
 
 
     if not path.isdir(path.dirname(config_path)):
@@ -399,15 +384,11 @@ Enter 'help()' for a list of commands""")
     if not path.isdir(settings["datadir"]):
         makedirs(settings["datadir"])
 
-    if not test:
-        from .keithley.keithley import init_keithley
     try:
-            k = init_keithley(beep_success=settings["beep"])
+        dev = _backend.init(beep_success=settings["beep"])
     except Exception as e:
         print(e)
-            exit()
+        exit(1)
-    else:
-        print("Running in test mode, device will not be connected.")
 
 
 if __name__ == "__main__":

m_teng/update_funcs.py

@@ -0,0 +1,123 @@
+import matplotlib.pyplot as plt
+import numpy as np
+
+import torch
+
+from teng_ml.util import model_io as mio
+from teng_ml.util.settings import MLSettings
+from teng_ml.util.split import DataSplitter
+
+from m_teng.backends.keithley import keithley
+
+def _update_print(i, ival, vval):
+    print(f"n = {i:5d}, I = {ival: .12f} A, U = {vval: .5f} V" + " "*10, end='\r')
+
+class _Monitor:
+    """
+    Monitor v and i data
+    """
+    def __init__(self, max_points_shown=None, use_print=False):
+        self.max_points_shown = max_points_shown
+        self.use_print = use_print
+        self.index = []
+        self.vdata = []
+        self.idata = []
+
+        plt.ion()
+        self.fig1, (self.vax, self.iax) = plt.subplots(2, 1, figsize=(8, 5))
+
+        self.vline,  = self.vax.plot(self.index, self.vdata, color="g")
+        self.vax.set_ylabel("Voltage [V]")
+        self.vax.grid(True)
+
+        self.iline,  = self.iax.plot(self.index, self.idata, color="m")
+        self.iax.set_ylabel("Current [A]")
+        self.iax.grid(True)
+
+    def update(self, i, ival, vval):
+        if self.use_print:
+            _update_print(i, ival, vval)
+        self.index.append(i)
+        self.idata.append(ival)
+        self.vdata.append(vval)
+        # update data
+        self.iline.set_xdata(self.index)
+        self.iline.set_ydata(self.idata)
+        self.vline.set_xdata(self.index)
+        self.vline.set_ydata(self.vdata)
+        # recalculate limits and set them for the view
+        self.iax.relim()
+        self.vax.relim()
+        if self.max_points_shown and i > self.max_points_shown:
+            self.iax.set_xlim(i - self.max_points_shown, i)
+            self.vax.set_xlim(i - self.max_points_shown, i)
+        self.iax.autoscale_view()
+        self.vax.autoscale_view()
+        # update plot
+        self.fig1.canvas.draw()
+        self.fig1.canvas.flush_events()
+
+    def __del__(self):
+        plt.close(self.fig1)
+
+
+class _ModelPredict:
+    colors = ["red", "green", "purple", "blue", "orange", "grey", "cyan"]
+    def __init__(self, instr, model_dir):
+        """
+        @param model_dir: directory where model.plk and settings.pkl are stored
+
+        Predict the values that are currently being recorded
+        @details:
+            Load the model and model settings from model dir
+            Wait until the number of recoreded points is >= the size of the models DataSplitter
+            Collect the data from the keithley, apply the transforms and predict the label with the model
+            Shows the prediction with a bar plot
+        """
+        self.instr = instr
+        self.model = mio.load_model(model_dir)
+        self.model_settings: MLSettings = mio.load_settings(model_dir)
+        if type(self.model_settings.splitter) == DataSplitter:
+            self.data_length = self.model_settings.splitter.split_size
+        else:
+            self.data_length = 200
+
+        plt.ion()
+        self.fig1, (self.ax) = plt.subplots(1, 1, figsize=(8, 5))
+
+        self.bar_cont = self.ax.bar(self.model_settings.labels.get_labels(), [ 1 for _ in range(len(self.model_settings.labels))])
+        self.ax.set_ylabel("Prediction")
+        self.ax.grid(True)
+
+    def update(self, i, ival, vval):
+        buffer_size = keithley.get_buffer_size(self.instr, buffer_nr=1)
+        if buffer_size <= self.data_length:
+            print(f"ModelPredict.update: buffer_size={buffer_size} < {self.data_length}")
+            return
+        else:
+            ibuffer = keithley.collect_buffer_range(self.instr, (buffer_size-self.data_length, buffer_size), buffer_nr=1)
+            vbuffer = keithley.collect_buffer_range(self.instr, (buffer_size-self.data_length, buffer_size), buffer_nr=2)
+        if self.model_settings.num_features == 1:  # model uses only voltage
+            data = np.vstack((ibuffer[:,0], ibuffer[:,1], vbuffer[:,1])).T
+            # print(f"data.shape:", data.shape)
+        else:
+            raise NotImplementedError(f"Cant handle models with num_features != 1 yet")
+        for t in self.model_settings.transforms:
+            data = t(data)
+        data = np.reshape(data[:,2], (1, -1, 1))  # batch_size, seq, features
+        with torch.no_grad():
+            x = torch.FloatTensor(data)   # select voltage data, without timestamps
+            # print(x.shape)
+
+            prediction = self.model(x)  # (batch_size, label-predictions)
+            prediction = torch.nn.functional.softmax(prediction)  # TODO remove when softmax is already applied by model
+            predicted = torch.argmax(prediction, dim=1, keepdim=False)  # -> [ label_indices ]
+            # print(f"raw={prediction[0]}, predicted_index={predicted[0}")
+            label = self.model_settings.labels[predicted[0]]
+            # print(f"-> label={label}")
+
+        self.bar_cont.remove()
+        self.bar_cont = self.ax.bar(self.model_settings.labels.get_labels(), prediction[0], color=_ModelPredict.colors[:len(self.model_settings.labels)])
+        # update plot
+        self.fig1.canvas.draw()
+        self.fig1.canvas.flush_events()

m_teng/utility/testing.py

@@ -0,0 +1,17 @@
+import numpy as np
+
+def testcurve(x, frequency=10, peak_width=2, amplitude=20, bias=0):
+    # 0 = pk - width
+    # 2pi = pk + width
+    # want peak at n*time == frequency
+    nearest_peak = np.round(x / frequency, 0)
+    # if not peak at 0 and within peak_width
+    if nearest_peak > 0 and np.abs((x - nearest_peak * frequency)) < peak_width:
+        # return sin that does one period within 2*peak_width
+        return amplitude * np.sin(2*np.pi * (x - nearest_peak * frequency - peak_width) / (2*peak_width)) + bias
+    else:
+        return bias
+
+def get_testcurve(frequency=10, peak_width=2, amplitude=20, bias=0):
+    return np.vectorize(lambda x: testcurve(x, frequency=frequency, peak_width=peak_width, amplitude=amplitude, bias=bias))
+

pyproject.toml

@@ -0,0 +1,35 @@
+[build-system]
+requires = ["setuptools"]
+
+[project]
+name = "k_teng"
+version = "1.0.0"
+description = "Interactive utility for I-V measurements with a Keitley 2600 SMU"
+requires-python = ">=3.10"
+readme = "readme.md"
+license = {file = "LICENSE"}
+authors = [
+    { name = "Matthias Quintern", email = "matthias@quintern.xyz" }
+]
+classifiers = [
+    "Operating System :: POSIX :: Linux",
+    "Environment :: Console",
+    "Programming Language :: Python :: 3",
+    "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
+]
+dependencies = [
+    "matplotlib>=3.6",
+    "numpy",
+    "pyvisa",
+    "pyvisa-py"
+]
+
+[project.urls]
+repository = "https://git.quintern.xyz/MatthiasQuintern/k-teng"
+
+
+[tool.setuptools.packages.find]
+where = ["."]
+
+[project.scripts]
+k-teng = "k_teng.k_teng_interactive:main"

readme.md

@@ -1,23 +1,39 @@
-# K-TENG
+# m-TENG
-Helper scripts and shell for measuring **T**ribo**e**lectric **N**ano**g**enerator-based sensor output with a Keithley 2611B SMU using pyvisa
+Helper scripts and shell for measuring **T**ribo**e**lectric **N**ano**g**enerator-based sensor output with a Keithley 2611B SMU or an Arduino
 
 ## Features
-### Useful functions for scripts
+
-- Measure Voltage and/or Current
-- Transfer buffer from device to host
-- Save/load as csv
-- Run lua script on device
-- Auto-filenames
 ### Interactive (shell) mode
 - Live view
 - Press button to stop
 - Save and load settings (default interval, data directory...)
 - Easily run arbitrary command on device
 
+
+### Useful functions for scripts
+- Measure voltage and/or current
+- Transfer buffer from measurement device to host
+- Save/load as csv
+- Run lua script on Keithley SMU
+- Auto-filenames
+
+## Available backends
+### keithley
+    Use a Keithley 2611B Source-Measure-Unit via *pyvisa*. This backend allows measuring both voltage and current simultaneously.
+
+### arduino
+    Use a Bluetooth capable Arduino with [https://git.quintern.xyz/MatthiasQuintern/teng-arduino](this software on the arduino).
+    This backend only allows measuring voltage using an Arduinos analog input pin (0-5 V, 10 bit resolution).
+
+### testing
+    Use the shell without measuring TENG output. When starting a measurement, sample data will be generated.
+
+
 ## Shell mode
-Start with:
+It is recommended to run the shell with ipython:
 ```shell
-ipython -i k_teng_interactive.py
+ipython -i k_teng_interactive.py -- -*X*
 ```
+Substitute *X* for `-k` for keithley backend, `-a` for arduino backend or `-t` for testing backend.
 
 Use `help()` to get a list of available commands