pleesr
princeton lab for electrochemical engineering systems research

Ardustat Operating Instructions:

This is a working document. If anything is not working or unclear please email me and let me know!

  1. Start Program. In Windows and Mac you double click, in Linux open a terminal and type "java -jar /Path/To/Ardustat/Ardustat"

  2. If you're using the 10 K range potentiometer, choose 10 K in the calibration box and hit "send". If you're using the 50 K range, do the same but with 50 set. If you're concerned about current or potential limits change these values to #s that suit you. Press "set".

  3. Press "Get Ports"

  4. Choose Port that your Ardustat is attached to.

    • Note that different operating systems handle the USB devices differently.
      • Windows treats serial devices as "COMX" ports. Each ardustat you introduce to a given installation of Windows will retain its COM port ID, thus, if you plug an Ardustat in and it is given id COM49, it will always be COM49.
      • Mac OS X uses the serial ID on the Ardustat. Because the underlying Arduino seems to create a random ID with every restart, the apparent ID will change with computer reboots or Ardustat plugging and unplugging (I'm working on fixing this, as it's pretty annoying). The ports you want will be of the form /dev/tty.usbserial-XXXXXXXX, where the x's differentiate the ardustats you have plugged in.
      • Linux treats each device in a relative manner. The names take the form /dev/ttyCOMX, where X starts at 0. Linux will always build from 0 up, and fill in if need be. Very confusing, but there it is. If you've accepted linux as your savior you should be used to this stuff by now. Hit "Connect"
  5. If you have multiple Ardustats connected, press "Find Me." The blue light should blink, assuring you of which device you are controlling

  6. Make sure that "Check send" is selected.

  7. Press OCV. This ensures that the Ardustat is measuring open circuit.

  8. Attach the device to be tested. Red is Cathode, Black is Anode. The Ardustats (now) cannot read negative potentials, so if you have it hooked up backwards the "Cell (V)" box will read "0", and chances are you'll be discharging the cell at a good clip. See "high impedance inputs"

  9. Use the "Cell Info Section" to describe the cell. Optional, but it comes in handy.

  10. In the "Logging" frame give the test run a name. The time, in unixtime, will always be appended to the file name you give when you hit "Start Logging" to prevent overwriting files. In Windows and Mac OS X the log files are kept in the Ardustat folder, in Linux, it is dependent on the folder you start Ardustat from. Two files are creates for every log: the data (.dat) and the cell info (.inf).

  11. Press "Start Logging". This will create the aforementioned files and data will be written continuously to the .dat file. The file is space separated (easily read into Excel, Octave, Matlab, etc) and the columns are:

    • Unixtime
    • Mode (0 = manual, 1 = OCV, 2 = PSTAT, 3 = GSTAT)
    • Resistance Calibration Offset
    • Resistance Calibration Slope
    • VCC Calibration
    • Cell Potential
    • DAC Potential
    • Potentiometer Resistance
    • Current
    • Raw Data
    • Raw Data
    • Raw Data
    • Raw Data
    • Raw Data
    • Raw Data

          Hit "Stop Log" to stop the file when you are done with your experiments
      
      1. The are two control mechanisms for the Ardustat, manual and scripted

        • To manually set potentiostat, or galvanostat, choose the appropriate radio button. The manual and resistance radio buttons are for advanced Ardustat calibration and are generally not used. Enter the desired set point in the text box, and hit "go".
        • To script conditional galvanostatic or potentionstatic cycling used the "Advanced" section. There are four modes of operation, based on DUALFOIL conventions. There are three #'s to each line. mode setting cutoff

      where

      Mode 0 => Constant current (mA) until a cutoff Potential (V) Mode 1 => Constant current (mA) for a given time (s) Mode 2 => Constant potential (V) until a cutoff current (mA) Mode 3 => Constant potential (V) for a given time (s)

      Thus, the successive lines

      0 1 2
      1 0 600
      0 -1 1.2
      3 1.8 3600
      1 0 0 (Every script must end with this!)

      would tell the Ardustat to

      Set current to 1.0 mA until potential reaches 2.0 V
      Set current to 0.0 mA for 600.0 seconds
      Set current to -1.0 mA until potential reaches 1.2 V
      Set potential to 1.8 V for 3600.0 seconds
      Set current to 0.0 mA for 0.0 seconds

      The syntax will be offputting at first, but don't worry, the Ardustat will parse the numbers into english that you have to approve before starting the test. Hit "Parse". If all looks good, hit "Go Jonny Go" (a throw back to the Jonny Galvo days). The Ardustat will go through the various settings and go to OCV when the cycle is finished. To repeat the script infinitely simply check the "repeat" box. To stop the cycling at any point hit "Stop Jonny Stop".