alexwhittemore/hottubpi

External heating controller for portable spas (Implemented as Node-Red flow on Raspberry Pi.)

hottubpi's Issues

Improve heating rate algorithm

At present, the heating rate algorithm uses a rolling average followed by a 5m delay to calculate the temperature difference between (5m average)-(5m average from 5m ago), multiplied out to an hour baseline, to calculate *F/hr. A second such block uses the same method to calculate (5m average)-(5m average from 20m ago).

This leaves a lot to be desired.

New algorithm options:

1. detect a new temperature value, and calculate dF/dt since last-new temperature value. Possibly use either averaging or schmidt-triggering to mitigate noise when the true temperature is near a LSB boundary.
2. detect a new temperature value, n LSBs away from a previous value and time, and calculate across that dF/dt. Probably still requires schmidt-triggering to increase accuracy/decrease noise sensitivity on the two endpoints.