Would it be possible to allow more environmental inputs besides CPM?

Maybe in the future. I think mw0uzo was looking to do something like this some time ago but never actually implemented anything. There is still much work needs to be done to radmon core though before I'll be implementing anything new. One of the things I started to do some time back was make radmon more 'modular', so to speak, so it would be easier to implement new things and make changes easily. I got about half way there but life got it's teeth into me again and I have had little time of late. So my answer can only be maybe at the moment.

There are some things to consider though, such as the actual necessity of extra sensors (for radmon.org) and database size. The database is fairly large as it stands right now, and with a station submitting every 60 seconds, that equates to just over 525,000 records every year. So if one extra sensor was added, records for just one user would increase to 1,050,000 records annually. 4 sensors would be 2,100,000 records, just for one user. Not every user will have more than the CPM, but some may. This brings into question (at least for me), why do I need to see your tube voltage? Why do I need to see the pressure at your station location. I understand you want to see these, but they are kinda pointless for other people. So implementing something like tube voltage probably wouldn't get done. However, air quality would be good for everyone, VOCs, PM 2.5/10 etc, humidity less so. Rain would be a good sensor to add as this rain is occasionally radioactive. So it is really a matter of getting a good balance of useful sensor readings that everyone can benefit from and that doesn't bloat the database with data that is only relevant to one person.

I will be revisiting this in the future, but only when radmon core has had sufficient work to accommodate extra things.

Comments/opinions on this form anyone would be very welcome.

Yes there is. When the RPi5 comes out we will need to migrate the server over, it makes sense to rebuild it somewhat.

The plan is to go MQTT and Node-Red so that users can effectively send whatever they like. CoAP would probably work too and somewhere around that would be a solution to take all the existing HTTP requests and pipe it into the new system.

There will be some sensible defaults of course, but it should be a lot more flexible and people could subscribe to other people's data if they want to.

What would be really nice is if there was an open source data management system that we could adapt into radmon.org. Research required.

Simomax has done a lot of tidy up work, so it would be nice to keep as much as possible of that too. The solution is in there somewhere, probably bolting on MQTT and Node-Red into our current website

The RPi5 is out:  https://thepihut.com/products/raspberry-pi-5?src=raspberrypi&variant=42531604955331