In the meantime I have created a project with the esp32 cam module. I have been reading the values of my swimming pool monitoring screen.
What I noticed when using the camera, is that it needs quite some distance for the focus, meaning that for the analog utility meters you will need some space…
For the OCR part I used the https://ocr.space/ free API and scheduled it every 10 minutes.
Hope this already gives you some ideas 
