Modular, open-source hardware and software for education and environmental monitoring.
The original WheeStat may look like a VHS tape box with a couple of wires stuck in it, but it is really a computer driven scientific instrument. The WheeStat is a three electrode potentiostat, an instrument that measures electric current exchanged between electrodes and chemicals in solution.
It was designed for teaching electrochemistry and quantitative analysis. It supports a variety of experiments including cyclic voltammetry and annodic stripping voltammetry.
What's it do?
The WheeStat is capable of measuring concentrations of trace metal ions in water, including lead, arsenic and mercury.
For more information, visit the WheeStat user's manual at the link below
Cycic Voltammetry (CV)
Linear Sweep Voltammetry
Differential Pulse Voltammetry (DPV)
Annodic and Cathodic Stripping Voltammetry
Chronoamperommetry (one and two step)
Repetative CV and DPV expeiments
Cyclic Square Wave Voltammetry
The microcontroller that drives the WheeStat comes loaded with software written in the "Arduino-like" program, Energia.
The WheeStat comes with our Graphic User Interface loaded on a USB flash drive. The GUI comes as an executable program for Windows 32 and 64 bit computers as well as source code written in the program Processing. At this point, we do not have the GUI application for Mac. We believe that the Mac App for OSX can be generated relatively easily (see this video). All experimental parameters are adjusted from your computer using our GUI. Data are displayed in real time on the GUI chart. Sequential experiments can be overlayed on the GUI chart. Once collected, data can be saved as CSV files and opened in excell (or another spreadsheet program).
All software is open source. Future updates can be downloaded for free from our GitHub site.
Hacking the WheeStat.
Want additional functionallity? Have some unique experiment that you want to run? No problem. The programming languages are simple to learn and you will have the source code. Even if you turn your instrument into a brick, it can be brought back to life by reinstalling the original code. If you fry the electronics, the odds are that you can fix it by buying a $13 piece of hardware from your choice of electronics vendors (Texas Instruments, Mouser or Digikey)
The WheeStat comes with two graphite stick electrodes and a simple Ag/AgCl reference electrode.
Kits are now available. Kit assembly is described here for the 5 series and here for the 7 series. They contain everything needed to put together a fully fuctional potentiostat. Let us know if you need materials to make a set of cheap electrodes. Instructions for asssembling a working reference electrode are here and here. All surface mount components come soldered in place. Minimal soldering required: wires to clips, wires to circuit board, headers to circuit board. That is it. Twenty six joints total.
Current code is provided on a usb flash drive.
This is a new look for the WheeStat. In addition to the original VHS tape box housing, we now offer the WheeStat fully assembled in a more professional appearing format.