Welcome to the hardpotato GitHub repository. Hard Potato is an open source Python API to control commercially available potentiostats. It enables researchers to write Python scripts that can include experimentation, immediate data analysis using any third-party library and/or the control of other instruments. Hard Potato facilitates the standardization of electrochemical experiments by keeping a record of the experiments and data analysis that can be later run again to ensure repeatability. It also facilitates the sharing of electrochemical protocols between researchers and groups that own different potentiostats.

Currently, the following potentiostats are included in the library:

• CHI1205B from CH Instruments (chi1205b)
• CHI1242B from CH Instruments (chi1242b)
• CHI601E from CH Instruments (chi601e)
• CHI760E from CH Instruments (chi760e)
• Emstat Pico from PalmSens (emstatpico)

with the following techniques:

• Cyclic voltammetry, CV
• Chronoamperometry, CA
• Linear sweep voltammetry, LSV
• Open circuit potential, OCP

For the CHI601E and CHI760E only:

• Normal pulse voltammetry, NPV

Open a console and type:

pip install hardpotato

Here are quick examples on how to use the library. For more help check the Wiki.

import hardpotato as hp

# Potentiostat setup
# Choose the correct model from ['chi760e', 'chi1205b', 'emstatpico']:
model = 'chi760e' 
# Write the path where the chi software is installed (this line is optional when
# using the Pico). Make sure to use / instead of \:
path = 'C:/Users/jrl/CHI/chi760e.exe' # This is ignored for the Pico
# Write the path where the data and plots are going to be automatically saved:
folder = 'C:/Users/jrl/Experiments/data'
# Setup:
hp.potentiostat.Setup(model, path, folder)

# Run CV with default values:
cv = hp.potentiostat.CV()
#cv.bipot() # uncomment to activate second working electrode
cv.run()

# Run a LSV with default values:
lsv = hp.potentiostat.LSV()
#lsv.bipot() # uncomment to activate second working electrode
lsv.run()

# Run a CA with default values:
ca = hp.potentiostat.CA()
#ca.bipot() # uncomment to activate second working electrode
ca.run()

# Run an OCP with default values:
ocp = hp.potentiostat.OCP()
ocp.run()

• Since the CHI potentiostat software only works in Windows, any script written with hardpotato will only work in Windows.
• The CHI translators use macro commands that are only available in the most recent versions of the software. Please contact CHI support for help on updating the potentiostat software and firmware.

• Contact PalmSens for instructions on how to update the firmware of the Pico.
• The communication to the Pico is done via the serial port, this means that no external software is required. Because of this, there is no live plotting, however, the data and plots are saved when the measurement is finished.
• Scripts written for the pico may also work in other operating systems, provided the library is installed correctly. So far, hardpotato with the Pico has been tested in Windows 10 and Manjaro Linux with kernel 5.15.xx; it has not been tested with MacOS although it should work.

• numpy for data handling
• matplotlib for plotting
• scipy for fitting
• pyserial for serial handling
• softpotato for electrochemical equations and simulations

• To CH Instruments for making their software flexible enough that it can be started from the Windows command line and for creating the Macros.
• To PalmSens for developing MethodScript and writing code for parsing data. The code is in the PalmSens MethodScript GitHub account.
• This development is funded by the Joint Center for Energy Storage Research (JCESR).

Hard Potato was developed at the Beckman Institute, University of Illinois at Urbana-Champaign, Feb 2021 to Jan 2023 by:

• Lead: Oliver Rodriguez (oliverrdz.xyz, [email protected])
• Support: Michael Pence ([email protected])
• PI: Joaquin Rodriguez-Lopez ([email protected])