Hello, i'm using a similar setup with the Hantek 6022BL and a OPT101 (https://www.ebay.com/itm/232458733138).
This chip includes a photodiode with a transimpedance amplifier which greatly simplifies the schematic needed:
For the software i would suggest the great PcScope made by Fabio1963 (https://www.dropbox.com/sh/qieod71ucovd6we/AADJvoBmMZNcR0kFB8ysS7vSa?dl=0).
Amazing. Could you test some of the newer iphones, in case they give you eyestrain as well? Im gonna do that on my work iphone where I have absolutely terrible and long lasting pain.
Yes the software looks crap compared to Zeitnitz. Also we might need to get a better photodiode just to be sure. I was recommended this - https://www.conrad.cz/pin-fotodioda-osram-components-bpx-61-to-39-vyz-uhel-55-400-1100-nm.k153122
@Wootever please what is the difference when you use the diode with the circuit as bought from ebay?
martin
The transimpedance amplifier converts current from the photodiode to a voltage usable by the oscilloscope (it basically amplify the signal for a more stable output).
The advantage of a combined/embedded design:
The integrated combination of photodiode and transimpedance amplifier on a single chip eliminates the problems commonly encountered in discrete designs, such as leakage current errors, noise pick-up, and gain peaking as a result of stray capacitance.
For Android there's an app called "HScope". It supports various Hantek devices, including the 6022BE. My first impression is that it's great software. It detects frequencies much better than OpenHantek does and generally seems very polished. We might be able to create a portable solution with an Android device, a USB On-The-Go cable, a power bank, 6022BE + probe, and the HScope app.
HScope App: https://play.google.com/store/apps/details?id=com.martinloren.hscope
Guide: http://hscope.martinloren.com
JTL Hantek says up to 48MS/s. The HScope guide says 48Ms/s are supported by the app: http://hscope.martinloren.com/oscilloscope-tables.html
martin No more than 240 Hz yet. I find the soundcard solution to be much more responsive. It even picks up my ceiling's 100 Hz incandescent flicker from afar while the Hantek oscilloscope receives a flat line. Maybe the photodiode needs an additional external voltage. The audio cable somehow might supply that voltage.
martin my setup is enclosed in a case so it's not easy to photograph. I started off with a cheap Amazon USB scope but found that I was hitting the limits pretty easily. My present scope was rather expensive and does an actual 500 MS/s so it won't ever be the weak link.
The special sauce is having a really clean power source and then adding a 100,000 ohm (or higher) resistor to amplify the fluctuations coming out of the diode. Also, be certain that the diode's switching rate is sufficiently fast to capture the frequency you're looking for.
@Wootever @TechSensitive The OPT101 PDF (first page) says "Bandwidth: 14 kHz". Does that mean no more than 14 kHz can be detected? Any thoughts?
http://www.ti.com/lit/ds/symlink/opt101.pdf
I got all the components, and did very bad solder work. To my surprise, the oscilloscope detects light input. But it's no better than the BPW34 yet. I can't get the 9V battery to work. I hold one end at VCC and the other end to any of the two probes, but the signal won't get amplified. Also the first signal was negative, so I had to swap hook and grapple. I don't know how to make progress. It seems impossible for an average person. I believe without the battery it won't detect any higher frequencies.
