New README file for optoelectrode Users

[John Seymour]

In our ongoing effort to communicate better, we have just added (11/15/18) a new README tab in the Excel file emailed with your probes Tracking #. Hopefully it sets better expectations for electrodes and uLEDs. Here's what it says:

We are improving our process to lower artifact and improve the robustness of the uLEDs so future versions will be even better.
Please keep in mind we are a research group -- just like yours -- and can only provide limited support.
We strongly encourage you to share your questions on our open forum and connect with other neuroscience labs.
Our goal is to deliver consistently high quality optoelectrodes with few defects. Given our current resource limitations and experience, we list the acceptable range below.
Note 1:	The optoelectrodes delivered will have at least 6 working uLEDs and 24 microelectrodes with acceptable impedance
Note 2:	An acceptable impedance range greater than 100 kOhm and below 1.5 MOhm
Note 3:	Flat I-V curves (I = 0 for all V) and linear lines (I = aV where a is not a function of V) indicate dead LEDs.
Note 4:	Artifacts are generated locally and sometimes globally on the recording channels. A normal stimulation artifact is 50-2000 uV and 50-200 us wide.
Note 5:	Do NOT exceed 100uA for any given channel.
Note 6:	If you choose to use a voltage driver, consider placing a high precision resistor in series and monitor current so you do not exceed the limit.
Note 7:	Tips on artifact removal can be found at the link above.