Is there any documentation about remote trigger actions? Which triggers are there, etc?
ref
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There is no overarching documentation. Mainly because how the trigger feature is used only depends on the package that implements them and how they use it varies a lot. Some examples:
- flap display allows you to append a line of text.
- scheduled player allows you to directly switch to a configured page.
- photo booth allows you to trigger taking the picture.
- control example shows a minimal example of how the feature can be used.
… and so on. Do you have an idea of what you’re trying to achieve?
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For example
In this time of COVID-19 we would like to hang a infrared camera on a screen and detect if someone has fever or not. If he/she has fever the door won’t open, else if he/se has not fever the door will automaticly open.
That’s sounds a bit error-prone:
- I imagine a forehead easily gets warmer when walking through the sun. That might result in false positives.
- It would probably require face detection as well, otherwise measuring anything via camera gets difficult. This requires either a secondary camera or maybe the same camera if detection with infrared only isn’t viable.
- Is an infrared camera’s temperature resolution even capable of that kind of precise measurement? The difference between 36.5°C and 37.5°C (for example) isn’t a lot. I remember a friend of mine having such a precise camera and was a lot more expensive than the Pi IR camera.
- This seems unrelated to info-beamer and you don’t need triggers for that. The only (completely unexplored path) might be to use the Pi infrared camera, try to get anything meaningful out of it, which I doubt, and use GPIOs for door control.
I guess the alternative to a real camera would be a minimal thermal camera like this one with much lower resolution. Although I’m not sure how usable the readings from those might be as it looks like a pixel soup.
We already sorted anything out, we have professional infrared cameras that also are being used at the army. Budget is not a problem. But I was just asking for any documentation about all the available triggers and the possibility for custom triggers
The triggering is meant for influencing the visual output behaviour of the screens. Tasks like adding content to a scroller, switching between videos/images and so on. It’s not a generic “if this event then that action” solution. For that, a package service can be used. This feature allows you to run additional programs on the Pi that can then implement any kind of logic and communicate with external hardware.
Although I feel that monitoring an infrared camera stream, reliably detecting a person’s temperature within that stream and then controlling doors feels a bit out of scope of what a Pi can do. Does the camera produce HDMI output?