working iv curve

2026-06-03 15:19:54 +02:00
parent 7c45d74226
commit 878b8bc5b0
13 changed files with 583 additions and 13 deletions
@@ -36,9 +36,4 @@ Thumbs.db               # Windows
 # ======================
 # Measurement data
 # ======================
-# Uncomment if you don't want raw data files in the repo
-# *.csv
-# *.dat
-# *.hdf5
-# *.h5
- 
+data/
@@ -9,7 +9,7 @@ Created on Wed Oct 05 14:27:45 2022
 # Function to output voltage in Volts
 # Keithley is the VISA resource for the Keithley-196
 def Voltage(Keithley):
-    Keithley.read_termination = '\n'
+    Keithley.write("X\n")
    Voltage_string = Keithley.read()
    Voltage = float(Voltage_string[4:])
    return Voltage
@@ -15,22 +15,29 @@ import os.path
 import numpy as np
 import matplotlib.pyplot as plt
 import pyvisa
+from pathlib import Path
 rm = pyvisa.ResourceManager()

 import SIM900_commands as SIM900_comm
 import SIM928_commands as SIM928_comm
 import Keithley196_commands as Keithley_comm

-Keithley_address = 'GPIB0::6::INSTR'
-SIM900_address = 'TCPIP0::ir-moxa01.psi.ch::3002::SOCKET'#'ASRL1::INSTR'
+Keithley_address = 'TCPIP0::Prologix-00-21-69-01-4e-fb.psi.ch::1234::SOCKET'
+# Keithley_address = 'GPIB0::6::INSTR'
+SIM900_address = 'TCPIP0::ir-moxa01.psi.ch::3001::SOCKET'#'ASRL1::INSTR'

 Keithley = rm.open_resource(Keithley_address)
 SIM900 = rm.open_resource(SIM900_address)
 SIM928_port = 1

 # Initialise Keithley
+Keithley.clear()
+Keithley.timeout = 5000
+Keithley.read_termination = '\n'
+Keithley.write("T5X\n") # Ensures the Keithley reads when it is triggered by "X" write
 Keithley_comm.Set_Mode(Keithley, "DC V")
 Keithley_comm.Set_Range(Keithley, "Auto")
+Keithley.read() # Throwaway 

 # Initialise SIM900
 SIM900_comm.flush_main(SIM900)
@@ -97,6 +104,7 @@ def measure_V(time_average=10, time_interval=0.2):
 # Currently doesn't read the voltage that was set, due to issues with querying through mainframe
 # Errors caluclated incorrectly
 def V_scan(V_start=1e-3, step_size=1e-3, V_end=2e-3, time_average=10, sample_name='no_name', contact_1 = '', contact_2 = '', light = 'Dark', temp=777, amplifier='SR570', gain=10**3, number_of_loops=0):
+    Keithley.clear()
    print('Measurement started: %s'\
          %(datetime.datetime.now().strftime("%Hh%Mm%Ss")))
    V_scan_list = np.linspace(V_start, V_end, int(abs(V_start-V_end)/step_size)+1)
@@ -106,7 +114,7 @@ def V_scan(V_start=1e-3, step_size=1e-3, V_end=2e-3, time_average=10, sample_nam
    SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.V_source_state("off")) #set source off
    # open a file to write data to 
    date_today = datetime.date.today() #date for making a directory
-    file_path = "C:/Jamie/IV-Data/" + str(date_today) + "/"
+    file_path = Path(__file__).parent / "data" / str(date_today)
    if not os.path.exists(file_path):#make the directory if it is not there
        os.mkdir(file_path)
    time_start = datetime.datetime.now().strftime("%Hh%Mm%Ss")
@@ -129,10 +137,11 @@ def V_scan(V_start=1e-3, step_size=1e-3, V_end=2e-3, time_average=10, sample_nam
        # A loop over all currents 
        
        i=0
-        set_voltage(V_scan_list[0])
-        time.sleep(5) #wait 3 sec to avoid large noise on first measurement
+        # set_voltage(V_scan_list[0])
+        # time.sleep(5) #wait 3 sec to avoid large noise on first measurement

        for V_scan_item in V_scan_list:
+            
            time_start_iteration= datetime.datetime.now()
            i = i+1
            set_voltage(V_scan_item)
@@ -191,7 +200,7 @@ def V_scan(V_start=1e-3, step_size=1e-3, V_end=2e-3, time_average=10, sample_nam
    return

 # V_start, step size, V_end, time average, sample name, contact 1, contact 2, light, temperature, amplifier, amplifier gain
-#V_scan(-1.0, 0.05, 1.0, 1.0, "test", "contact1", "contact2", "MIR", 300, "SR570", 10**(7)) #amplifier sensitivity = 1/gain
+V_scan(-1.0, 0.05, 1.0, .1, "test", "test1", "test1", "MIR", 300, "SR570", 10**(7)) #amplifier sensitivity = 1/gain
 #V_scan(-1.0, 0.1, 1.0, 1.0, "SHADWELL", "posContactC", "negContactF", "MIR", 18, "SR570", 10**(8)) #amplifier sensitivity = 1/gain
 #V_scan(0.0, 0.1, 1.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
 #V_scan(0.0, 0.2, -2.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
@@ -0,0 +1,38 @@
+# Program to do I-V measurements
+# Using SIM928 voltage source within SIM900 mainframe
+# Using Keithley196 for voltage measurement
+
+import time
+import datetime
+import os.path
+import numpy as np
+import matplotlib.pyplot as plt
+import pyvisa
+from pathlib import Path
+rm = pyvisa.ResourceManager()
+
+import SIM900_commands as SIM900_comm
+import SIM928_commands as SIM928_comm
+import Keithley196_commands as Keithley_comm
+
+Keithley_address = 'TCPIP0::Prologix-00-21-69-01-4e-fb.psi.ch::1234::SOCKET'
+# Keithley_address = 'GPIB0::6::INSTR'
+SIM900_address = 'TCPIP0::ir-moxa01.psi.ch::3001::SOCKET'#'ASRL1::INSTR'
+
+Keithley = rm.open_resource(Keithley_address)
+SIM900 = rm.open_resource(SIM900_address)
+SIM928_port = 1
+
+# Initialise Keithley
+Keithley.clear()
+Keithley.timeout = 5000
+Keithley.read_termination = '\n'
+Keithley.write("T5X\n") # Ensures the Keithley reads when it is triggered by "X" write
+Keithley_comm.Set_Mode(Keithley, "DC V")
+Keithley_comm.Set_Range(Keithley, "Auto")
+Keithley.read() # Throwaway
+
+# Initialise SIM900
+SIM900_comm.flush_main(SIM900)
+SIM900_comm.reset(SIM900)
+SIM900_comm.flush_port(SIM900, SIM928_port)
@@ -6,9 +6,11 @@ readme = "README.md"
 requires-python = ">=3.9"
 dependencies = [
    "datetime>=5.5",
+    "ipykernel>=6.31.0",
    "jupyter>=1.1.1",
    "matplotlib>=3.9.4",
    "numpy>=2.0.2",
    "pyvisa>=1.14.1",
+    "pyvisa-py>=0.7.2",
    "scipy>=1.13.1",
 ]
@@ -0,0 +1,130 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "7e9d23ea",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# -*- coding: utf-8 -*-\n",
+    "\"\"\"\n",
+    "Created on Mon Oct 10 16:05:44 2022\n",
+    "\n",
+    "@author: gac-x01dc\n",
+    "\"\"\"\n",
+    "\n",
+    "# Program to do I-V measurements\n",
+    "# Using SIM928 voltage source within SIM900 mainframe\n",
+    "# Using Keithley196 for voltage measurement\n",
+    "\n",
+    "import time\n",
+    "import datetime\n",
+    "import os.path\n",
+    "import numpy as np\n",
+    "import matplotlib.pyplot as plt\n",
+    "import pyvisa\n",
+    "from pathlib import Path\n",
+    "rm = pyvisa.ResourceManager()\n",
+    "\n",
+    "import SIM900_commands as SIM900_comm\n",
+    "import SIM928_commands as SIM928_comm\n",
+    "import Keithley196_commands as Keithley_comm\n",
+    "\n",
+    "Keithley_address = 'TCPIP0::Prologix-00-21-69-01-4e-fb.psi.ch::1234::SOCKET'\n",
+    "# Keithley_address = 'GPIB0::6::INSTR'\n",
+    "SIM900_address = 'TCPIP0::ir-moxa01.psi.ch::3001::SOCKET'#'ASRL1::INSTR'\n",
+    "\n",
+    "Keithley = rm.open_resource(Keithley_address)\n",
+    "SIM900 = rm.open_resource(SIM900_address)\n",
+    "SIM928_port = 1\n",
+    "\n",
+    "# Initialise Keithley\n",
+    "Keithley.clear()\n",
+    "Keithley.timeout = 5000\n",
+    "Keithley.read_termination = '\\n'\n",
+    "Keithley.write(\"T5X\\n\") # Ensures the Keithley reads when it is triggered by \"X\" write\n",
+    "Keithley_comm.Set_Mode(Keithley, \"DC V\")\n",
+    "Keithley_comm.Set_Range(Keithley, \"Auto\")\n",
+    "Keithley.read() # Throwaway\n",
+    "\n",
+    "# Initialise SIM900\n",
+    "SIM900_comm.flush_main(SIM900)\n",
+    "SIM900_comm.reset(SIM900)\n",
+    "SIM900_comm.flush_port(SIM900, SIM928_port)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "91371dcc",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "V_value = -0.2\n",
+    "SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.set_voltage(V_value)) # get voltage \n",
+    "\n",
+    "SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.V_source_state(\"on\"))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "5236610b",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "9298c70d",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "-0.2001732"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# time.sleep(0.1)\n",
+    "Keithley_comm.Voltage(Keithley)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "19bb6089",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "automated-iv-curves",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.12.13"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
@@ -171,6 +171,8 @@ source = { virtual = "." }
 dependencies = [
    { name = "datetime", version = "5.5", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
    { name = "datetime", version = "6.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
+    { name = "ipykernel", version = "6.31.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
+    { name = "ipykernel", version = "7.2.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
    { name = "jupyter" },
    { name = "matplotlib", version = "3.9.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
    { name = "matplotlib", version = "3.10.9", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
@@ -179,6 +181,8 @@ dependencies = [
    { name = "numpy", version = "2.4.6", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.11'" },
    { name = "pyvisa", version = "1.14.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
    { name = "pyvisa", version = "1.16.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
+    { name = "pyvisa-py", version = "0.7.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
+    { name = "pyvisa-py", version = "0.8.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
    { name = "scipy", version = "1.13.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
    { name = "scipy", version = "1.15.3", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.10.*'" },
    { name = "scipy", version = "1.17.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.11'" },
@@ -187,10 +191,12 @@ dependencies = [
 [package.metadata]
 requires-dist = [
    { name = "datetime", specifier = ">=5.5" },
+    { name = "ipykernel", specifier = ">=6.31.0" },
    { name = "jupyter", specifier = ">=1.1.1" },
    { name = "matplotlib", specifier = ">=3.9.4" },
    { name = "numpy", specifier = ">=2.0.2" },
    { name = "pyvisa", specifier = ">=1.14.1" },
+    { name = "pyvisa-py", specifier = ">=0.7.2" },
    { name = "scipy", specifier = ">=1.13.1" },
 ]

@@ -3023,6 +3029,40 @@ wheels = [
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 ]

+[[package]]
+name = "pyvisa-py"
+version = "0.7.2"
+source = { registry = "https://pypi.org/simple" }
+resolution-markers = [
+    "python_full_version < '3.10'",
+]
+dependencies = [
+    { name = "pyvisa", version = "1.14.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
+    { name = "typing-extensions", marker = "python_full_version < '3.10'" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/82/14/fffb2de1baaa3dd6e30940a9882d742365baffa3ba4dade0260ddaee6390/PyVISA-py-0.7.2.tar.gz", hash = "sha256:4c5f5b867858457dbebfff92a42fba2d8b046d28defbbec2a09e3c1f0850e851", size = 95701, upload-time = "2024-03-07T12:05:31.696Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/70/7b/9c9cbb09596d00a3a5b009559e9b859ac459d01611fea6b3b655f74dc323/PyVISA_py-0.7.2-py3-none-any.whl", hash = "sha256:c53b941a5ee6547aadc5321f930c924dd5c4434891bc512fcafcdd5a4a8d110d", size = 75570, upload-time = "2024-03-07T12:05:29.72Z" },
+]
+
+[[package]]
+name = "pyvisa-py"
+version = "0.8.1"
+source = { registry = "https://pypi.org/simple" }
+resolution-markers = [
+    "python_full_version >= '3.14'",
+    "python_full_version >= '3.11' and python_full_version < '3.14'",
+    "python_full_version == '3.10.*'",
+]
+dependencies = [
+    { name = "pyvisa", version = "1.16.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
+    { name = "typing-extensions", marker = "python_full_version >= '3.10'" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/55/8d/0f1af2b39feca8868d0692a2c5d0c47f4ad559a051fb678c441fe1e99536/pyvisa_py-0.8.1.tar.gz", hash = "sha256:db53d3219d971d16b8f7c764a93e08475875063635b9ad8ea3c988439833ccdd", size = 102061, upload-time = "2025-09-04T20:48:21.639Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/70/0b/06ccf917ce30d78d75e452d0afc89236b1d384b776c5c33d75c8cc55fbe7/pyvisa_py-0.8.1-py3-none-any.whl", hash = "sha256:31208a2933c1793b4e829ba5f07d265b83f280668df440ee7ee6ac505dea4ee9", size = 82206, upload-time = "2025-09-04T20:48:20.13Z" },
+]
+
 [[package]]
 name = "pywin32"
 version = "311"
@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Wed Oct 05 14:27:45 2022
+
+@author: Jamie
+"""
+# Function for controlling Keithly-196 for electrical measurements
+
+# Function to output voltage in Volts
+# Keithley is the VISA resource for the Keithley-196
+def Voltage(Keithley):
+    Keithley.write("X\n")
+    Voltage_string = Keithley.read()
+    Voltage = float(Voltage_string[4:])
+    return Voltage
+
+# Function to set measurement mode
+# Keithley is the VISA resource for the Keithley-196
+# mode is the measurement mode
+def Set_Mode(Keithley, mode):
+    if mode == "DC V":
+        mode_number = 0
+    elif mode == "AC V":
+        mode_number = 1
+    elif mode == "Ohm":
+        mode_number = 2
+    elif mode == "DC I":
+        mode_number = 3
+    elif mode == "DC I":
+        mode_number = 4
+    elif mode == "AC I":
+        mode_number = 5
+    elif mode == "ACV dB":
+        mode_number = 6
+    elif mode == "Offset comp Ohm":
+        mode_number = 7
+    Keithley.write("F"+str(mode_number))
+
+# Function to set voltage range
+# Keithley is the VISA resource for the Keithley-196
+# range_name is the number of the range setting (numbers in V)
+def Set_Range(Keithley, range_name):
+    if range_name == "Auto":
+        range_number = 0
+    elif range_name == "0.3":
+        range_number = 1
+    elif range_name == "3":
+        range_number = 2
+    elif range_name == "30":
+        range_number = 3
+    elif range_name == "300":
+        range_number = 4     
+    Keithley.write("R"+str(range_number)+"X")
@@ -0,0 +1,230 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Mon Oct 10 16:05:44 2022
+
+@author: gac-x01dc
+"""
+
+# Program to do I-V measurements
+# Using SIM928 voltage source within SIM900 mainframe
+# Using Keithley196 for voltage measurement
+
+import time
+import datetime
+import os.path
+import numpy as np
+import matplotlib.pyplot as plt
+import pyvisa
+from pathlib import Path
+rm = pyvisa.ResourceManager()
+
+import SIM900_commands as SIM900_comm
+import SIM928_commands as SIM928_comm
+import Keithley196_commands as Keithley_comm
+
+Keithley_address = 'TCPIP0::Prologix-00-21-69-01-4e-fb.psi.ch::1234::SOCKET'
+# Keithley_address = 'GPIB0::6::INSTR'
+SIM900_address = 'TCPIP0::ir-moxa01.psi.ch::3001::SOCKET'#'ASRL1::INSTR'
+
+Keithley = rm.open_resource(Keithley_address)
+SIM900 = rm.open_resource(SIM900_address)
+SIM928_port = 1
+
+# Initialise Keithley
+Keithley.clear()
+Keithley.timeout = 5000
+Keithley.read_termination = '\n'
+Keithley.write("T5X\n") # Ensures the Keithley reads when it is triggered by "X" write
+Keithley_comm.Set_Mode(Keithley, "DC V")
+Keithley_comm.Set_Range(Keithley, "Auto")
+Keithley.read() # Throwaway 
+
+# Initialise SIM900
+SIM900_comm.flush_main(SIM900)
+SIM900_comm.reset(SIM900)
+SIM900_comm.flush_port(SIM900, SIM928_port)
+
+# Function to read the voltage set by a voltage source    
+def read_source_V():
+    count = 0
+    voltage = SIM900_comm.send_query(SIM900, SIM928_port, SIM928_comm.read_voltage(), 128) # get voltage
+    print("returned data: "+voltage)
+    while (count<10) and (type(voltage)!= float):
+        try:
+            voltage = float(voltage)
+        except:   
+            print('no float')
+            voltage = SIM900_comm.send_query(SIM900, SIM928_port, SIM928_comm.read_voltage(), 128) # get voltage
+            print("returned data: "+voltage)
+        count = count + 1
+    return voltage
+
+#print(read_source_V())
+
+# Function to set voltage of SIM928
+def set_voltage(V_value=1e-3):
+    if V_value > 20:
+        print ('Voltage setting too high (>10V), it is set to 10V')
+        V_value = 20
+    elif V_value < -20:
+        print ('Voltage setting too high (<-10V), it is set to -10V')
+        V_value = -20
+    SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.set_voltage(V_value)) # get voltage 
+    time.sleep(1)
+#    count = 0
+#    while (count<10) and (read_source_V()!= V_value):
+#        print('Setting voltage again')
+#        time.sleep(1) #wait 1 second
+#        SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.set_voltage(V_value)) # get voltage  
+#        count = count + 1
+    SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.V_source_state("on"))
+    print('Voltage set to ' + str(V_value))
+#    return read_source_V()
+
+# Function to measure the current from the Keithley voltmeter
+# time_average is the averaging time, time_interval is the time between points
+# Could also use "Filter (P)" command to set the Keithley's internal averaging time
+def measure_V(time_average=10, time_interval=0.2):
+    N_points = time_average/time_interval + 1 
+    V_list = []
+    i = 1
+    Keithley_comm.Set_Range(Keithley, "Auto") #set auto range
+    time.sleep(time_interval)
+    while i < N_points:
+        V_list.append(Keithley_comm.Voltage(Keithley)) #read the voltage
+        time.sleep(time_interval)
+        i = i+1
+    V_avg_ = np.mean(V_list, dtype=np.float32)
+    V_std_ = np.std(V_list, dtype=np.float32)
+    V_err_ = V_std_/(N_points)**(1/2)
+    return [V_list, V_avg_, V_err_]
+
+
+# Function to do I-V measurements
+# Currently doesn't read the voltage that was set, due to issues with querying through mainframe
+# Errors caluclated incorrectly
+def V_scan(V_start=1e-3, step_size=1e-3, V_end=2e-3, time_average=10, sample_name='no_name', contact_1 = '', contact_2 = '', light = 'Dark', temp=777, amplifier='SR570', gain=10**3, number_of_loops=0):
+    Keithley.clear()
+    print('Measurement started: %s'\
+          %(datetime.datetime.now().strftime("%Hh%Mm%Ss")))
+    V_scan_list = np.linspace(V_start, V_end, int(abs(V_start-V_end)/step_size)+1)
+    for n_l in range(number_of_loops):
+        V_scan_list = np.append(V_scan_list,np.linspace(V_end, V_start, (abs(V_start-V_end)/step_size)+1))
+    print(V_scan_list)
+    SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.V_source_state("off")) #set source off
+    # open a file to write data to 
+    date_today = datetime.date.today() #date for making a directory
+    file_path = Path(__file__).parent / "data" / str(date_today)
+    if not os.path.exists(file_path):#make the directory if it is not there
+        os.mkdir(file_path)
+    time_start = datetime.datetime.now().strftime("%Hh%Mm%Ss")
+    filename_root = "%s_%s_%s_%s_%s_scan_at_%sK_%s" % \
+    (time_start, sample_name, contact_1, contact_2, light, temp, amplifier)
+    filename = filename_root + "_averaging%ss.txt" % (time_average)
+    plotname = filename_root + "_averaging%ss.png" % (time_average)
+    filename2 = filename_root + "_raw.txt"
+    full_name = os.path.join(file_path, filename)
+    full_plotname = os.path.join(file_path, plotname)
+    full_name2 = os.path.join(file_path, filename2)
+    #data_file=open(str(full_name),'w')
+    with open(str(full_name),'w') as data_file, open(str(full_name2),'w') as raw_V_file:
+        data_file.write("Time\tVoltage_source[V]\tVoltage_meas[V]\tVoltage_meas_err[V]\tGain[V/A]\n")
+        raw_V_file.write("Voltage_source[V]\tVoltage_meas[V]\n")
+        # just for ploting here
+        V_plot_list = []
+        V_err_plot_list = []
+        V_scan_plot_list = []
+        # A loop over all currents 
+        
+        i=0
+        # set_voltage(V_scan_list[0])
+        # time.sleep(5) #wait 3 sec to avoid large noise on first measurement
+
+        for V_scan_item in V_scan_list:
+            
+            time_start_iteration= datetime.datetime.now()
+            i = i+1
+            set_voltage(V_scan_item)
+            time.sleep(2) #wait 5 sec	for signal to settle
+            # measure+read+write the data          
+            V_source = V_scan_item
+#           V_source = read_source_V()
+            [V_list, V_avg, V_err] = measure_V(time_average=time_average, time_interval=0.2)
+            time_now = datetime.datetime.now()
+            data_string = "%s\t %s\t %.5e\t %.5e\t %s\n"\
+                                                   %(time_now, V_source, V_avg, V_err, gain)
+            data_file.write(str(data_string)) 
+            raw_V_file.write("%s\t %s\n" %(V_source, V_list))
+            V_plot_list.append(V_avg)
+            V_err_plot_list.append(V_err)
+            V_scan_plot_list.append(V_source)
+
+            #make plot
+            plt.close()
+            plt.plot(V_scan_plot_list, V_plot_list,'+')
+            plt.title(str(sample_name))
+            plt.xlabel('Source Voltage / V')
+            plt.ylabel('Measured voltage / V')
+            plt.draw()
+            plt.pause(0.1)
+            plt.show(block=False) 
+            iteration_time = datetime.datetime.now()-time_start_iteration
+            remaining_time = iteration_time.total_seconds()*(len(V_scan_list)-i)
+            print(time.strftime('remaining time: %H:%M:%S',\
+                                time.gmtime(remaining_time)))
+         
+        I_list = [V_plot_list[i]/gain for i in range(len(V_plot_list))]
+        I_err_list = [V_err_plot_list[i]/gain for i in range(len(V_plot_list))]  
+        plt.close()
+        plt.figure()
+        plt.errorbar(V_scan_plot_list, I_list, yerr=I_err_list, fmt='+')
+        plt.title(str(sample_name))
+        plt.xlabel('Source Voltage / V')
+        plt.ylabel('I / A')
+        plt.tight_layout()
+        plt.grid()
+
+        plt.savefig(full_plotname)
+        plt.draw()
+        plt.pause(0.001)
+        plt.show(block=False)
+        plt.close()
+        
+    data_file.close() 
+    raw_V_file.close()
+    set_voltage(0)
+    SIM900_comm.send_command(SIM900, SIM928_port, SIM928_comm.V_source_state("off")) #set source off
+    print('Source turned off')
+    print('Measurement finished: %s'\
+          %(datetime.datetime.now().strftime("%Hh%Mm%Ss")))
+    return
+
+# V_start, step size, V_end, time average, sample name, contact 1, contact 2, light, temperature, amplifier, amplifier gain
+V_scan(-1.0, 0.05, 1.0, .1, "test", "test1", "test1", "MIR", 300, "SR570", 10**(7)) #amplifier sensitivity = 1/gain
+#V_scan(-1.0, 0.1, 1.0, 1.0, "SHADWELL", "posContactC", "negContactF", "MIR", 18, "SR570", 10**(8)) #amplifier sensitivity = 1/gain
+#V_scan(0.0, 0.1, 1.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
+#V_scan(0.0, 0.2, -2.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
+#V_scan(0.0, 0.2, 2.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
+#V_scan(0.0, 0.3, -3.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
+#V_scan(0.0, 0.3, 3.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
+#V_scan(0.0, 0.5, -5.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
+#V_scan(0.0, 0.5, 5.0, 1.0, "Sun", "posContactB", "negContactH", "MIR", 18, "SR570", 10**(9)) #amplifier sensitivity = 1/gain
+
+"""
+# Set up the plot
+plt.ion()  # Enable interactive mode
+figure, ax = plt.subplots(figsize=(10, 6))  # Create a figure and an axes
+ax.set_title("Live Number Update")
+
+# Loop to update the number and plot every second
+for _ in range(9999):  # Limiting to 10 iterations for demonstration
+    number = Keithley_comm.Voltage(Keithley)
+    # Create a new plot for the current number
+    figure, ax = plt.subplots(figsize=(10, 6))
+    ax.text(0.5, 0.5, str(number), fontsize=100, ha='center')  # Display the number in the center
+    ax.set_title(f"Number: {number}")
+    ax.axis('off')  # Turn off the axis
+
+    plt.show()  # Show the plot
+    time.sleep(2)  # Pause for a second
+"""
@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Mon Oct 10 12:41:44 2022
+
+@author: gac-x01dc
+"""
+
+# Sends a command to the instrument
+# SIM900 is the VISA resource for the SIM900
+# port_number is the port number of the instrument to be controlled
+# instrument_command is the command to be sent
+def send_command(SIM900, port_number, instrument_command):
+    SIM900_command = "SNDT "+str(port_number)+", \""+instrument_command+"\""
+    SIM900.write(SIM900_command)
+
+# Send a query to the instrument and get a response - CURRENTLY BROKEN
+# SIM900 is the VISA resource for the SIM900
+# port_number is the port number of the instrument to be controlled
+# instrument_query is the query to be sent
+# response_bytes is the maximum number of bytes in the response
+def send_query(SIM900, port_number, instrument_query, response_bytes=7):
+    send_command(SIM900, port_number, instrument_query)
+    SIM900_command = "GETN? "+str(port_number)+", " + str(response_bytes)
+    full_response = SIM900.query(SIM900_command)
+    print("full_response="+full_response)
+    response = full_response[5:]
+    print("response="+response)
+    return(response)
+    
+# Flushes input & output buffers of specified port
+def flush_port(SIM900, port_number):
+    SIM900_command = "FLSH "+str(port_number)
+    SIM900.write(SIM900_command)
+    
+# Flushes output queue of mainframe
+def flush_main(SIM900):
+    SIM900_command = "FLOQ"
+    SIM900.write(SIM900_command)
+
+# Resets all ports
+def reset(SIM900):
+    SIM900_command = "SRST"
+    SIM900.write(SIM900_command)
@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Mon Oct 10 15:39:12 2022
+
+@author: gac-x01dc
+"""
+
+# Program containing functions with commands for SIM928 voltage source
+
+# Turns source on/off
+def V_source_state(on_off = 'off'):
+    command = 'EXON ' + on_off
+    return(command)
+
+# Set voltage of SIM928
+def set_voltage(V_value=1e-3):  
+    if abs(V_value) < 1e-3:
+        print ('Voltage too low (<|3 mV|), it is set to 0 mV')
+        V_value = 0
+    elif abs(V_value) > 39:
+        print ('Voltage setting too high (>39V), it is set to 39V')
+        V_value = 40e-3
+    V_value = round(V_value,3) # rounding to mV, otherwise the source does not set the voltage because it lacks the precision
+    command = 'VOLT ' + str(V_value) # set voltage
+    return(command)
+    
+# Read voltage set by voltage source    
+def read_voltage():
+    command = 'VOLT?'
+    return(command)