Posted by JimG on 04/13/2011 10:13 PM
#3
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greencardigan wrote:
1. Heavy filtering on ambient temps. Does this occur before or after cold junction compensation?
2. Light filtering of temps for display and logging
3. Heavy filtering of temps for ror calcs
4. Heavy filtering of ROR values for display and logging
All filtering is done at the end, i.e., after CJ compensation, TC linearization, etc.
The ambient temps are heavily filtered on the idea that the ambient sensor is located in a stable environment (on the PCB, presumably inside an enclosure) so variations are most likely noise. So we kill the quick jumps and keep the longer term trends.
Heavily filtered streams of BT and ET values are used for computing the derivatives (RoR). These heavily filtered BT and ET streams are used
only for the calculation of derivatives.
Optionally, the streams of computed RoR values can also be post-filtered. This works surprisingly well. I did some testing while Bill was writing aGesha and found that a combination of pre- and post-filtering for RoR gives better results with less lag time than pre-filtering BT and ET only.
More lightly filtered streams of BT and ET are computed for logging and displaying the data.
A lot of flexibility is built into the code for filtering. Different combinations of sensors and roasters produce varying amounts of signal noise. A lot of air flow will usually create more noise, for instance.
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greencardigan wrote:
Also, are you eventually intending to make aBourbon compatible with both pBourbon and Artisan?
The current release candidate of aBourbon is up to date with your changes to pBourbon.
I chose to write a standalone sketch to support Artisan instead of trying to build more functionality into aBourbon. I've tested aArtisan on the desk, but not on my roaster. It works very well on the desktop, FWIW:
https://tc4-shiel...hes/RB-100
Jim