Photodiode setup

Jaewon, I saw on the old website that you were asking for photodiode recommendations. What is your setup for using the photodiode tuner? I currently have a Thorlabs Mounted Photodiode, part number  SM1PD1B, which works great if all I'm doing is hooking it up to my ephys system and detecting black/white squares, but it doesn't seem compatible with the photodiode tuner (polarity is backwards and the signal amplitude is very low compared to what ML expects). Could you please let me know what you have and how you've set it up?

I use the one built by the engineers that I am working with here, so there is no brand name or part number that I can give. I recently redesigned the tuner so that you can change the voltage threshold yourself, but haven't thought about polarity reversal. I guess I can add the feature easily. Please give me some time to make that change.

Would you download the new package and test? Now it should autodetect the polarity from the baseline voltage.

If it works okay, would you upload a screenshot? (Click the tuner window, press ALT+PrtScn, open Paint and press CTRL+V.) One shortcoming of my photodiode is that it doesn't give me clear, square-shaped responses. If yours looks good, I may want to buy one.

Hi Jaewon, it looks like the most recent version of ML is from a few days ago (build 206, Feb 10). Has the change been uploaded? If the build number has just not been changed, it looks like it still isn't working, we (I work w Mitch) get an error saying no signal detected, cannot perform tuning. I've tried making the "new threshold" as low as 1 with no success. I've attached a screenshot of the ML photodiode tuner interface, as well as what the signal looks when we hook the photodiode up to Intan and run a one-shot test through ML. The voltage scale on the intan screenshot is +/- 1V.

Thanks for the figures. When you guys said the signal amplitude is low, I didn't realize how low it is. Please overwrite your mlphotodiodetuner.m with the attached file. You will be able to set the voltage range manually, if the detected range doesn't serve you well.

We're detecting a signal now, but there still appear to be a couple of issues: 1) The voltage range on the plot seems to vary dramatically between individual single-shot tests (see two examples attached), even though a measurement we took outside of monkeylogic shows that they never go beyond 0 to -0.4V. The range of values seems reasonable (~0.3V) but the baseline varies wildly. 2) The multishot test isn't working, possibly because of this? We aren't getting any error messages, and no flashes show up on the monitor.

Please check your AI ground configuration. Signal fluctuation is not a problem of NIMH ML. It is because of improper wiring and hardware settings.
https://monkeylogic.nimh.nih.gov/docs_NIMultifunctionIODevice.html#AIGroundConfiguration