I had this same question. Would like to use for just measuring potentials, like ORP, pH, ISE, etc. From my research, if you take the counter electrode out of the circuit, you can make this measurement. I haven't got one to try this on yet. Suggest you research "open circuit potential" on web. Seems to be similar question on other potentiostats.
I think Excel will let you do this. Just plot one of the graphs with its time axis; then add the second graph, with its time axis. Excel will locate the points properly. If you want to get fancy, you could write code in Python, or any other scientific programming language, that interpolates between time points and give you estimated graph points from one graph at the other graph's time points.
I'm attempting to implement something similar to perform AC voltammetry at higher sample rates and frequency but am struggling with my understanding of Arduino code. Where exactly in serviceDataBuffer (in ps_system_state.cpp) does the If statement go?
I've tried inserting if (run_complete) into a few places that seeem logical to me but either it has no effect or everything breaks.
Could anyone enlighten me as to how to implement these changes in greater details?
Thanks for your feeback. You're right about my system specific differences, even for param dt =0.05 I get a median of 0.058.
I've attempted to implent the firmware changes outlined as I only need a sample rate of 115Hz however I haven't noticed any difference. I'm not very familar with arduino programming and I suspect I haven't implmented the changes in ps_system_state.cpp correctly. I've attached my changes in hopes that you might notice some sort of obvious error.
// Check for last sample flag to see if done
bool run_complete = false;
if ((run_complete = true));
// Empty data buffer
buffer_size = dataBuffer_.size();
while (buffer_size > 0)
sample = dataBuffer_.front();
buffer_size = dataBuffer_.size();
// Send indication that the run is complete
lastSampleFlag_ = false;
From my comprehension of chronoamperometry, the applied voltage is regarding the reference terminal which bodes well that the affidavit ought to happen fundamentally on the working anode, while the counter cathode serves to finish the circuit. In any case, I might want to realize is it conceivable to accomplish an in any event, covering on the counter anode simply like how it is on the functioning terminal? All runs I had so far shows rather lopsided coatings that increments with applied voltage.
The Rodeostat FeatherWing does use slightly lower cost components than the Rodoestat in order to keep costs down. However, overall the accuracy of the Rodeostat FeatherWing is fairly comparable to the Rodeostat. The main differences are as follows.
The Rodeostat FeatherWing has a more limited fixed voltage output range (+/- 1.65V) whereas the Rodeostat has a four voltage ranges which can selected via software(+/- 1, 2, 5, 10V).
The Rodeostat FeatherWing comes in a single fixed current range, which is specified at time of purchase, whereas the current range for the Rodeostat can be selected via software (+/- 1, 10, 100, 1000) .
Finally, the Rodeostat is a complete USB instrument which comes preprogrammed with firmware and can be controlled from the host PC using our python library or with Webapp software. In contrast the Rodeostat FeatherWing is designed to be used as an expansion board and only works when connected to a Feather development board, such as Adafruit's Feather M4 Express, PyBadge or PyGamer. You need to write your own firmware for controlling the Rodestat FeatherWing on the Feather development board.
It is not possible to run multiple experiments, such as constant and cyclic voltammetry, simultaneously with the multiplexed version of the Rodeostat. You can use up to 7 working electrodes, but you still only have 1 reference and 1 counter electrode. So the time course of the potential between the all of the working electrodes and the reference electrode will be the same during a test.
I followed your instructions on checking the sensor board - and everything is fine now. I'm not sure if it had an impact, but I did switch to a new USB hub that may provide a bit more power than the ancient Mac Mini I was using before. I know that the USB connection can definitely cause issues with Arduinos - but I do not know that it was the cause of this problem.