Disable drivers that need serial port support if libserialport is not found.
Also, disable building various other serial port related code in that case.
Most Metex DMMs use e.g. " mV" as unit field, others use "mV ",
though. Support these (and other) whitespace variants by stripping all
spaces and only comparing non-space characters.
strcmp(buf + 9, " mA") does not work because buf is CR-terminated,
while " mA" is NUL-terminated.
Drop ambiguities arising from the termination of the strings, and
only compare the characters we care about, using strncmp().
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
When the parser found a space, it treated it as an invalid digit
and discarded the whole packet. This behavior was incorrect on
2000 count devices, where the first digit can be sent as a space
rather than a '0'.
Convert spaces to '0' and parse them as usual.
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Uwe Hermann
Alexandru Gagniuc