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General Category => Do-more CPUs and Do-more Designer Software => Topic started by: RBPLC on July 09, 2021, 02:14:40 PM

Title: LERP and FILTER
Post by: RBPLC on July 09, 2021, 02:14:40 PM
Would it be possible to combine LERP and FILTER into a single instruction? This would allow performing both actions without having to use an intermediate variable. Since both of these are commonly used with analog I/O, seems like it would be worthwhile to have them combined.
Title: Re: LERP and FILTER
Post by: BobO on July 09, 2021, 02:57:30 PM
Would it be possible to combine LERP and FILTER into a single instruction? This would allow performing both actions without having to use an intermediate variable. Since both of these are commonly used with analog I/O, seems like it would be worthwhile to have them combined.

If we did we'd just be doing it as a macro with a dummy variable between them. Since the intermediate variable doesn't really need to be retained between scans, I'd personally just allocate a single R location, label it Scratch, and use it as the glue between every such operation in the PLC.
Title: Re: LERP and FILTER
Post by: franji1 on July 10, 2021, 07:26:44 AM
Would it be possible to combine LERP and FILTER into a single instruction? This would allow performing both actions without having to use an intermediate variable. Since both of these are commonly used with analog I/O, seems like it would be worthwhile to have them combined.

Another solution to smooth the analog value would be a CERP instruction, Cubic intERPretation, similar to what Do-more does in the AXCAM instruction.  We have talked about doing this instruction since we did AXCAM, but never implemented it.

Look at AXCAM editor to possibly see if a CERP instruction would be useful or not.