KronTalk
Chronos => Chronos User Discussion => Topic started by: clkdiv on June 18, 2021, 04:42:32 AM
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On my Chronos 2.1 I would like to grab the Frame Sync Output at the BNC to feed it into an Arduino. For visual feedback, I tried very slow 3 fps on the Chronos to toggle an LED.
But the output of the Chronos is always high, it simply is closed and doesn't do anything. Someone any advice?
Thanks!
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So i just tried on mine, does behave very much as i would expect it to by just selecting the "Frame Sync Output" option on the BNC I/O Selection Menu.
Tested some Random FPS/ Shutter-Angle Settings, and connected it to my Trusty Hameg HM 412 Oscilloscope (easy enough with just an BNC Cable ;) ).
Shot some bit of Footage of that Test, and tried to include a Shot of the Camera I/O Settings, as well as the Recording Settings and Oscilloscope Settings for each test for a bit of reference to voltage and Timing.
Tested on 3fps, 60fps (Shorter and Longer Exposure), 10kfps.
all work fine for me.
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Only advise i could give right now would be to compare your settings to the one i used there and try again, those worked for me.
I also dont know what LED you are using, and what kind of output current this output is meant for, but if you use a too Powerfull LED, some Current Limiting circut could kick in, and output would always stay low (Overcurrent maybe looks like short circut for the Camera, so its always low). Oscilloscope obviously doesnt draw any substantial current, so voltage-wise the Signal is sure there on mine. If that turns out to be the Problem, maybe add some kind of Pre-Amp to it like some OP-Amp Circut, so the OP-Amp would provide the Current needed for whatever you want to drive with that signal, if you want to be sure.
Maybe a completely wrong guess from my side, but worth mentioning.
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Also in case you where not aware, shutter angle does affect the Output signal, so if your test is running at whatever FPS (lets assume 3), and your Shutter angle is set to 1° or 359°, your LED would then either be basically off or on the Whole time, and i dont know if the Hi/Lo indicator on the I/O-Settings-Page would even care to change for that short bit of time. Just FYI. if you didnt so far, try again with 180° Shutter.
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Hey nikon1,
thanks for you reply. I have some more weird things going on with the camera. I wanted to trigger to toggle camera recording, but it doesn't do that anymore too. The strange thing: the hi/lo-indicator at the trigger/io-setup page reliably show the signal. So it is definitively not at hardware issue.
as far as i can see, the shutter does not matter at 3 fps, no? Also i am sure it is not the led, the led runs fine when triggered by code. If i code it that the led lits up for a second everytime the signal CHANGES, it does not light up too. So there is definitively nothing coming from the camera, i guess.
but much worse for no is that i cant trigger it remotely anymore.
any ideas. thanks.
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Shutter does in fact very much matter!
Problem with 3 FPS is, that the Chronos with current Software does not really allow you to change the Shutterspeed /-angle via the Thumb wheel for low Framerates. starts to be a Problem at like 60fps, where you wont quite be able to go all the way up to 359° Shutter, unless you use the Touchscreen controls and push that slider all the Way up. Allows you to lower the Shutter angle with the Thumbwheel from 359° back however. Gets way worse with super Low Framerates, and the Thumbwheel becomes basically unusable at 3fps and alike. Use the Slider on the Touchscreen when you for some reason use or have to use THAT low FPS Settings. Already told the Guys at Krontech about this UI Glitch / Bug, and they will have a look at it.
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So now back to WHY the Shutter does matter.
As you can see in the Footage i posted (compare 180° and 58° at 60fps!), The Signal corresponds to Exposure Time and will only give a signal for the time it is actually exposing.
i think if you set it to 3fps, default Shutter-Angle is set to 1° for some reason. Now lets think about what happens here. you have the 1/360s Part of 1/3s "on-time" where you are basically exposing. Which will result in an Exposure time of 1/1080s or 0,926ms, which is a damn short bit of time. Depending on how responsive or slow the LED is (also needs *SOME* time to light up and go dark again, still faster than a Tungsten Bulb, but it isn't immediate!), that will be really hard to see, even if you have really good eyes. at the very least it probably would be quite dim if visible at all.
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As i already said, i highly recommend you to try again with 180° Shutter, if you want to try the LED at 3FPS as a visual Indicator (or just use a Oscilloscope if available).
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About the Trigger via BNC, while i played around with Triggering Externally, i havent really used it so far apart from testing. Only got an issue once or twice, but that could easily have been me not knowing what i am Doing, all the other times worked ok for me. So maybe someone who used BNC Triggers more than me can help here or give some comment, if this tends to be an common Issue or something.
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You could also try to hook up the LED and run the camera at like 1000fps and play with the shutter-Angle.
Should be effectively a dimmer, as the Signal is Basically a PWM Square-Wave.
Quick Demonstration as Video Attached at 1000fps.
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but much worse for no is that i cant trigger it remotely anymore.
any ideas. thanks.
If nothing else helps, maybe try a complete new Installation of the Firmware on a Spare microSD card and keep the old one you are using right now around just in case.
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Hello nikon1, thanks a lot.
Thanks you for testing. I'll try tomorrow.
For the moment I am much more concerned about the fact that the input behaves so strange.
When setting IO1 BNC to
Threshold = 2.50
Mode = Toggle
20mA Pullup = checked
and any other options off and no cable attached to the BNC input, IO1 is HIGH.
I suppose this is false. If nothing is connected, it should be low, like IO2 and Input 3, right?
It is even HIGH, if all Ports are set to "None". Would you mind to see how it is at your camera, please?
Nevertheless shortening and opening the switch results in changing to LO and back to HIGH, reliably.
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With the Settings you listed, BNC is High.
See video attached.
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Ok, when unchecking the 20mA pullup, it states signal is LO. So this was my fault here, I think.
Now I tried to trigger the camera from IO2 by shortening pins 4 and 5, labeled "COM and TRG2". Same behavior there as IO1.
Still, signals are reported on the screen as if everything was okay, but still I cant end recording.
Now, when setting IO1 or IO2 to "Shutter gating", every shortening/opening results in capturing a single frame. So, the hardware is working correctly, right? Its just I cant end record/toggle. Hmmmmm.
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Are you also on 0.6.0?
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Yes, all tests above where done on Version 6.0
However, i have older version here to also test on Micro-SDīs ready to go, let me know, if you need tests for any other Versions as well.
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What i noticed while recording the Last video about the Trigger Input/ Toggle, that the Camera seems to be a bit Picky about how long the BNC needs to be "shorted" (=signal/ Pulse Length), for it to work properly. If you press the Trigger for long, and only release it a while after, it wont toggle Record Status. Needs to be a somewhat short, distinct Pulse.
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Thank you so much! I can use the BNC to start record, but not to stop anymore. starting is reliable, stopping impossible then. what the hell can that be? ok i have to go to bed, will go on tomorrow. Thanks again
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SOLVED: Now since the issue appeared at IO1 and IO2 and since the shortening/opening was actually recognized by the camera (the indicators reported it correctly), I was quite sure this was not a hardware issue. So the signal came to the cam but it did neither make the camera toggle nor end recording. It had to be a software issue.
I flashed the system card and really, at least triggering works as suspected again. So it WAS a software issue. I'll check frame sync output now too, but I am quite sure this will work now too.
How can such thing happen? One thing I have learned from this is: I will for sure have a readymade second microSD with the operating system in my camera bag!
I'll post here, if the frame sync output was fixed too. Thanks again nikon1! Thanks for your efforts!
OT and BTW.: I think I will have the money for the speedbooster soon! Cu! Martin
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How can such thing happen? One thing I have learned from this is: I will for sure have a readymade second microSD with the operating system in my camera bag!
Seems like a Smart Thing to do if you actually need to rely on the Camera working. Just as with Spare Memory cards for Saving Footage and so on. I personally carry around a Micro SD with Software 6.0 and one with 5.1 Unstable wherever i go with the Camera, for other Reasons, but i guess it would also make for a good backup OS card, in case the SD card would break or data on the Card got corrupted for whatever reason. Might not happen too often (or at least shouldnt...), but still better to be save than sorry. Stuff breaks sometimes.
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OT and BTW.: I think I will have the money for the speedbooster soon! Cu! Martin
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Nice. How is your Memory upgrade going btw? Just curious.
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Ok, here is the last update with this: After having reinstalled OS 0.6.0 not only the IO triggers do again but also the Frame Sync output. I tested that as nikon1 suggested: using the shutter to dim the led. Smart! Thanks!
OT: Memory still the same. I will address that later.
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Jesus! After testing more with the camera, same thing happened again! Starting possible, ending not.
After reinstallation of the OS everything fine again! @nikon1: Did you ever really work with the trigger-IOs?
Thanks! Martin
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No.
About the Trigger via BNC, while i played around with Triggering Externally, i havent really used it so far apart from testing. Only got an issue once or twice, but that could easily have been me not knowing what i am Doing, all the other times worked ok for me. So maybe someone who used BNC Triggers more than me can help here or give some comment, if this tends to be an common Issue or something.
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Jesus! After testing more with the camera, same thing happened again! Starting possible, ending not.
After reinstallation of the OS everything fine again! @nikon1: Did you ever really work with the trigger-IOs?
Thanks! Martin
I think I have run into this before and my solution was to connect the camera to a computer via Ethernet and trigger it via the web interface and then it worked again. This definitely sounds like a software bug of some kind.
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Thanks. What do you mean exactly? You triggered it via web interface and afterwards it worked again without ethernet but with the BNC?
Just asking, because triggering via web has not been an issue here, but it also is no option for what I want to do. Thanks!
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Thanks. What do you mean exactly? You triggered it via web interface and afterwards it worked again without ethernet but with the BNC?
Just asking, because triggering via web has not been an issue here, but it also is no option for what I want to do. Thanks!
Yeah, once I triggered it via the web, it worked again via the BNC without being connected via Ethernet. Give it a try the next time it happens. I'd be curious if it (temporarily) fixes the problem for you too. It's not an ideal work-around, but certainly better than reloading the OS!
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Jesus! After testing more with the camera, same thing happened again! Starting possible, ending not.
After reinstallation of the OS everything fine again! @nikon1: Did you ever really work with the trigger-IOs?
Thanks! Martin
I am quite late to the discussion, my apologies for that. But here are few suggestions for the next time you run into a triggering issue:
1- Confirm the Post-trigger values in the Record Settings > Trigger Delay values are set to zero to prevent any delays when stopping a recording. In case the triggers do not work as expected, confirm trigger delays are correctly configured.
2- Try resetting all trigger settings to default through the web interface, before selecting new settings. You can follow the steps in this video to do so: https://drive.google.com/file/d/1XFY_nbaKKQ6fjOXx__c-8174lve2eKCB/view?usp=sharing
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OK thanks. I never touched post trigger delays. I will surely try the reset configuration option, if the issues appears again. Thanks.