No pictures this update - but some information on the process of making the whole thing work.
As seen in the last update, the prototype hardware construction is complete. All the solder-y and nuts & bolts-y parts are done. What's left is figuring out what exactly to do with all the data we are getting from the sensors.
This is easier said than done. I can read the sensors just fine but deciding what to do with the data at a high level is a bit tricky.
Testing reveals that my current methods are good enough to tell the sensors are working -- but not well enough to reliably isolate anomalies. False positives (detecting Peril where there is none) and false negatives (failing to detect Peril) abound. I need to re-evaluate my software.
It helps to define the problem. Here is what we want:
Ignore slow and steady changes, and take action only on anomalous signals.
To do this we need to:
- Read sensors regularly and keep a history; from that we can establish what "normal" is.
- Figure out what "anomalous" readings actually means for each sensor. (This can be different per sensor - is slow but steady change upwards for the past two minutes anomalous for Ambient Temperature? What about for Ambient Sound level or Ambient Light level?)
- Constantly re-adjust for one, and watch out for the other.
No matter what method or thresholds we use for sensors, the common thread is that we need to take and keep accurate measurements over time. Only by comparing what's happening to what has already happened can we make judgments about normal vs anomalous.
The existing software does this, but as stated - not well enough. Some software work should sort this out. I'm reminded of why Signals Processing is an entirely separate discipline, because it's easier said than done!