owfs errors : BUS_select_subbranch

I've been getting errors on owfs for some time now, but after reading the doco and discovering the error stats, i thought i would look into it more.

$ grep -v " 0" /var/1wire/bus.0/interface/statistics/*error*
/var/1wire/bus.0/interface/statistics/errors:         359
/var/1wire/bus.0/interface/statistics/select_errors:         359

turning on debug on owfs with "--error_print 1 --error_level 5"

Then you get to see things like this:

Jan  6 14:00:37 ubuntu OWFS[32423]:   DEBUG: ow_select.c:BUS_select_subbranch(178) Selecting subbranch 1F 8F 67 05 00 00 00 B6
Jan  6 14:00:37 ubuntu OWFS[32423]:   DEBUG: ow_bus_data.c:BUS_send_data(38) Response doesn't match data sent

but this doesnt tell me what branch is at fault main/aux

So i edited the following file in the source code and recompiled

1-wire, long runs and owfs

My 1-wire MicroLAN has a long run using BT cable (the stuff that comes into your house from the pole outside) it's not the most capable and CAT5 is better if you can use it, but mine runs through my flowerbeds into my greehouse, so it needed to be semi-amoured.

Long runs need slightly different 1-wire slew rates or you get lots of errors and devices drop off your LAN :(




Maxim Application Note 148 states:



Testing with long and short bus lines has shown that the optimum timings for all networks are as follows:

Pulldown Slew Rate: 1.37V/μs
Write One Low Time: 11μs
Data Sample Offset/Recovery: 10μs

So with owfs how do you do that with your Maxim USB dongle...?