Triggering multiple cameras with a single digital output

I'm sure this is a very amateur question but Im not finding clear answers in my googling.

I'm working on a project that requires triggering 4 cameras (each with 10Kohm input impedance...3.3V LVCMOS logic) using a single digital out on an Arduino, but I cant seem to figure out how to configure things to avoid ending up with an overly attenuated signal that wont reliably trigger all 4 cameras at once (currently I just have 4 BNC cables [probably 50ohm] connected to each camera and terminating together at the digital out, but this leads to a big voltage drop on all the cables). Any guidance would be much appreciated!

Thank you

(deleted)

spycatcher2k: Opto isolate the trigger output, to each of the 4 channels, or look at direct port manipulation, and drive 4 outputs.

Thank you for the input!

I assume the idea with direct port manipulation would be having better control over timing to use 1 digital out/camera?

Could you expand a bit on why the optoisolator? I'm generally familiar with how and why these are used in power supply circuits but don't quite follow with why it works here?

I'm working on a project that requires triggering 4 cameras (each with 10Kohm input impedance) using a single digital out on an Arduino, but I cant seem to figure out how to configure things to avoid ending up with an overly attenuated signal

It should be no problem. Let's see... The "absolute maximum" current rating for an Arduino output is 40mA... That's 125 ohms... That's 80 10K resistors in parallel.

There's something "funny" with one or more of those "10K" inputs. Or, maybe one of your cables is shorted?

nobilecw: I'm sure this is a very amateur question but Im not finding clear answers in my googling.

I'm working on a project that requires triggering 4 cameras (each with 10Kohm input impedance...3.3V LVCMOS logic) using a single digital out on an Arduino, but I cant seem to figure out how to configure things to avoid ending up with an overly attenuated signal that wont reliably trigger all 4 cameras at once (currently I just have 4 BNC cables [probably 50ohm] connected to each camera and terminating together at the digital out, but this leads to a big voltage drop on all the cables). Any guidance would be much appreciated!

Thank you

you left out how the cameras are triggered. How did you measure when you determined the signal was attenuated? And how did you determine there was a big voltage drop on all the cables?

Paul

Check your code - maybe you left out pinMode (pinX, OUTPUT); something simple like that.

Flash units I have dealt with needed a low on their input to trigger them.

You are working with rather low voltages in the first place, 3.3 volts. Then have four 10k ohm resistors in parallel results in 2500 ohms. And then the capacitance of 50 ohm cable will slow the pulse a bit, depending on the cable length. I wonder what the actual camera specs are for the shutter? Is it really 3.3 volts?

If one camera works out of four, there must be some big differences in performance of cameras.

Paul