So, here’s my challenge…
I have a display (light emitting) which will tell me when I have enough power from my solar panels to justify running an optional pond pump. I don’t need to run it all the time so I’d like to run it when I’ve got power to waste.
I already have a home automation that tracks production of power and I have a threshold production where I automatically start the pump - using a couple of TAPO power sockets BUT I don’t know what the sum total of all other consumption is around the house so I don’t known if I have spare power.
Now I have an indicator that lights up when I have excess power - but it is only a visual indication and I can’t ‘read’ it using any of the usual options. So I have built a light detector to drive an ESP-01m (still waiting for some parts for the restart tri-state interlock circuit). This is a bit prone to light pollution where the sensitivity changes depending on how bright the incidental light on the screen is. So the preferred solution would be a camera that literally looks at the display and when this field is active, starts the pump.
I have some ESP32s, ESP8266s, several Raspberry pies and I’m running Home assistant on a mini PC. My background is in SW development, but I haven’t used C++ and I dabble in simple electronics. Can anyone suggest a way to reliably monitor this display for this event, on a device that can report to HomeAssistant when the status changes?
I’ll need to be able to restrict the detection area of the camera or produce a mask for the the icon I am watching for.
My first thought was an ESP with a camera… but I can’t see a way to monitor for a specific part of the field of view on devices running ESPHOME, or even to report changes of image. Maybe there is a suitable HA add on to do image recognition in the PC?
Then I considered a Raspberry pi Zero with a camera, there should be some suitable SW available to the image processing - but how do I make an RPi into a HA client?
All to save a couple of pence worth of power… Still it’s a fun little project, and any suggestions will be most welcome.