Related, does anyone know of an app that can read gauges from an image and log the number to influx? I have a solar power meter in my crawlspace, it is inconvenient to go down there. I want to point an old phone at it and log it so I can check it easily. The gauge is digital and looks like this:
This[1] is something I've come across but not had a chance to play with, designed for reading non-smart meters that might work for you. I'm not sure if there's any way to run it on an old phone though.
Wow. I was looking at hooking my water meter into home assistant, and was going to investigate just counting an optical pulse (it has a white portion on the gear that is in a certain spot every .1 gal) This is like the same meter I use, and perfect.
(It turns out my electric meter, though analog, blasts out it's reading on RF every 10 seconds unencrypted. I got that via my RTL-SDR reciever :) )
You'll be happier finding a replacement meter that has an interface to monitor it directly or a second meter. An old phone and OCR will be very brittle.
Not OP, but it sounds like the kind of project I’d undertake.
Happiness for me is about exploring the problem within constraints and the satisfaction of building the solution. Brittleness is often of less concern than the fun factor.
And some kinds of brittleness can be managed/solved, which adds to the fun.
I would posit that learning how the device works, and how to integrate with a newer digital monitoring device would be just as interesting and less brittle.
Possibly! But I’ve recently wanted to dabble with computer vision, so I’d be looking at a project like this as a way to scratch a specific itch. Again, not OP so I don’t know what their priorities are, but just offering one angle for why one might choose a less “optimal” approach.
...start digging around and you'll likely find something. HA has integrations which can support writing to InfluxDB (local for sure, and you can probably configure it for a remote influxdb).
You're looking at 1xRaspberry PI, 1xUSB Webcam, 1x"Power Management / humidity management / waterproof electrical box" to stuff it into, and then either YOLO and DIY to shoot over to your influxdb, or set up a Home Assistant and "attach" your frankenbox as some sort of "sensor" or "integration" which spits out metrics and yadayada...
4o transcribes it perfectly. You can usually root an old Android and write this app in ~2h with LLMs if unfamiliar. The hard part will be maintaining camera lens cleanliness and alignment etc.
The time cost is so low that you should give it a gander. You'll be surprised how fast you can do it. If you just take screenshots every minute it should suffice.
Since it's at home, you'll have WiFi access, so it's pretty much a rudimentary Kotlin app on Android. You can just grab a photo and ship it to the GPT-4o API, get the response, and then POST it somewhere.
https://www.pvh2o.com/solarShed/firstPower.jpg