Looking for guidance on an idea. Call me the crazy beekeeper.

I want to make a little circuit that reads a couple of analog signals every half hour and store the measurements. When I come by in a day or a month later, I want my computer to sync up with the controller and download those data points. If memory fills up, just start overriding old data (just like security camera systems do). And I need to make a bunch of these.

I am an old-fart electrical engineer (graduated in the 80's). I've programmed microchip parts before, not my strong suit but I can do it. I'd love to make this into a phone app, but that's maybe something I could hire someone to do? I just want the part that will talk bluetooth to my laptop for now.

My first question is, should I design my own circuit, or use a 'bluetooth module'? I know the biggest difference is simply they build the antenna into the PCB. A couple of bucks isn't a big deal to this. But how would I 'connect' their module to my circuit board that has the analog reading components?

 

It is doable. But firstly, you need to get some numbers down on paper.

What data are you collecting every 30 minutes?
How many channels and how many bits per channel?
From this, you can determine your data storage requirements.

Next, you need an MCU (micro controller unit) that is up to the task. Then you need a blue-tooth module. You can do it with Arduino, ESP32, or something similar.

Finally, you need a phone with bluetooth capability and an app to fetch the data. It is possible to write your own app if you're up to the challenge.

 

My first question is, should I design my own circuit, or use a 'bluetooth module'?

Use a module. The chip to make your own would likely cost more than the module.