Hi all, I’m trying to get a Pivariety AR0234 global shutter camera working on a Raspberry Pi 3, and the plan is to drive it with an external trigger signal coming from a machine. The thing that’s confusing me is the instructions/video show a second camera adapter card sitting between the RPi and the AR0234. Can the AR0234 be connected directly to the Pi, or is that second card mandatory?
Second question: in the video there is no trigger signal cable going into the AR0234 and none going into that second adapter card either. Is that because of the extra adapter card, or is the video just a showcase/demo and the trigger wiring was simply left out?
Any clarification would be great, I’m a bit stuck on which wiring path is correct before I power anything up.
Hi, welcome to the forum. Let’s sort this out. A couple of things I need before I can give you a straight answer:
The SKU printed on the module (or on the label/box)
The PCB revision number silkscreened on the board
Which Raspberry Pi model you’re using
What voltage level your external trigger signal runs at
Once I know the exact SKU/revision it’s much easier to say whether that second adapter board belongs in your setup or not, since the hardware has changed between revisions.
I’m following the provided instructions for setup with an external trigger signal, and I’m basically trying to determine whether the second camera adapter card between the RPi and the AR0234 is mandatory, or whether the AR0234 can connect directly to the RPi 3. That’s the part of the instructions that doesn’t line up for me.
That explains the confusion. The B0353 has been updated to a single board module design — there is no additional adapter board in the current product. The instructions/video you’re looking at show an older layout with that second camera adapter card between the Pi and the camera, and that no longer applies to the updated single-board B0353.
One important warning though: do not try to connect the original camera without the adapter board if you’re working off the old wiring, as it may cause problems during use. With the updated single-board B0353 the adapter board isn’t part of the chain in the first place, so follow the current product page rather than the older video.
OK, thank you! That clears up the adapter board question.
But now I need the technical specifications for the trigger signal, and I’ve run into a second problem. The “calculations Example” picture that was provided has no explanation of its parameters, so I can’t tell what any of the numbers refer to.
What are the absolute maximum and minimum voltage values for the trigger signal, i.e. 1.8Vdc +/- how much? And how much current will the trigger input sink, or what is its impedance?
See the attached picture from the “your calculations Example” — there’s no explanation of what the parameters are:
2.1 What is TTF (time to flash?)
2.2 LPPCK = 612 — what is this value?
2.3 The last line needs explanation and what values were used there (530?, 2.6 us?)
I’m replying to your earlier message about the B0353 single board module — this is the follow-up on the trigger side.
Good, glad the adapter board part is clear now. On the trigger electrical side, the trigger input on this module is referenced to 1.8Vdc logic — that’s the level your external trigger should be driving against. I don’t want to give you a number for the absolute max/min or the input sink current/impedance off the top of my head, because those are datasheet-level figures and I’d rather have the correct numbers than a guess. Let me pull the exact values from the hardware team.
On the calculation example image: TTF is “Time To Flash” as you suspected — it’s a timing parameter used in the exposure/sync calculation, not something you set directly. LPPCK = 612 and the values in the last line (530, 2.6 us) are all inputs to that same calculation, and without the parameter legend it’s impossible to tell which is which, so I’ve asked for the definitions that go with that example too.
Thanks, that helps me understand the shape of it at least. I’ll wait for the exact numbers. Just to be clear about what I actually need so I can wire the trigger from my machine correctly:
Absolute max / min voltage for the trigger input (so I know the tolerance around 1.8Vdc)
Input current sink or input impedance
A proper legend for TTF, LPPCK = 612, and the last line values (530, 2.6 us) in the calculation example
Do not attempt to connect the original camera without the adapter board, as that may cause problems during use.
Trigger signal is referenced to 1.8Vdc logic.
Still open: the absolute max/min trigger voltage, the trigger input sink current / impedance, and the parameter legend for the calculation example (TTF, LPPCK = 612, and the last line values 530 / 2.6 us).
I don’t have confirmed values for those three yet, so I won’t guess — I’ll post them here as soon as the hardware team gets back to me. In the meantime, don’t apply the trigger source to the input until we’ve confirmed the max/min and impedance, so nothing gets damaged.
