How about it? Experiments of the third kind , take 999999.

How about it? Experiments of the third kind , take 999999. Update Putting the parts together

There has a been a lot of design effort in the main board, and I added several features. On thing that immediately is visible is the alarm kill button. Actually it is a switch with a spring contact, as I could not find any fitting push button. The idea is that once that alarm beeper goes of, the first thing one will want to do is silence it (could be middle of the night too). So pressing the lever will silence it (but not for long). If the error is fatal and not simply an unplugged mains adaptor, then you need to terminate the experiment, and just save whatever data was stored by connecting a PC with RS232.

This shows the bottom of the main board, with the black box:

This the component side:

An extra low drop out stabilizer was added to run the MAX232 so also communication is available if only battery power remains. A special anti-reset circuit was added in case the MAX232 craps out., a low or bad signal on RS232 in on the PIC would cause continuous interrupts, overloading the black box micro controller and causing a watchdog reset. this circuit prevents that. And a special battery present circuit was added signaling bad contacts and the like in the battery backup circuit, even if it is running from mains. Some other tricks were added too, component count went right up. Note the missing fuse, its not missing, on the other side is a very thin wire.. Could not find a fuse .. where are those ??

Here the front panel with the RS232 connector, power connector, and the alarm reset lever:

Put it all in the alu box, it just fits:

But where to put this beeper?

On the PCB is the simplest, will have to cut away some thermal insulation foam: