Inverting the Signal

[jonas-frei]

There is an example on the wiki about inverting the signal: https://wiki.eeros.org/eeros_architecture/hal/scaling_multi

Using this inv stage does not result in an inversion but some really strange behaviour (output goes to max value and remains there). I assume that there is a bug in the JsonPaser::calcScale function (https://github.com/eeros-project/eeros-framework/blob/6fcc962cfdb4e6042cf93f5dc00996a6de4ca210/src/hal/JsonParser.cpp line 193).

If I use

{"id" : "inv",
  "scale": -1.0, "offset": 0.0 }

instead of

{"id" : "inv",
  "minIn":   -1.0, "maxIn":  1.0,
  "minOut":  1.0, "maxOut": -1.0 }

as suggested by the wiki, then it works. So the problem is most likely somewhere on the lines 283-289.

Sidenote: using

{"id" : "inv",
  "scale": -1.0 }

works as well, since the hal does not check if the offset parameter is given and then just assumes that it is 0. This might be a feature or an additional bug.