Output modules are now guaranteed:
- Every option is always given, with the default value if not supplied
by the user, and is the right GVariantType.
- No invalid options are ever passed.
Audio tools processing WAV failes generally need the samples to be in
the range -1 to +1. The scale option adds postprocessing to any samples
going into a WAV file, by dividing the sample values by the given factor.
The Brymen BM25x series supports the BC-20X that is an opto-isolated
serial cable. The link seems to be unidirectional i.e. when activated
the DMM periodically sends updates to the host while the host cannot
control the DMM in any way.
The protocol is documented in "6000-count-digital-multimeters-r1.pdf"
that is available from the manufacturer. Every 15 byte packet consists
of a bitmap where the bits correspond to segments or symbols on the
LCD display i.e. the DMM essentially sends the contents of its screen
to the host in every update. This driver then decodes the measured
quantity, unit and its value from the bitmap.
This is intended for setting (or getting) the amplitude of a source
which doesn't really have an MQ associated with it, such as the demo
driver's analog channels.