Hi Robert, On 01/03/2012 07:32 AM, Robert Conway wrote:
[...] > I have on my network > > 2 x Hubs (Hobby Boards) > > Humidity, UVI, Barometer (Hobby Boards) > > DS18S20,DS18S20, DS 18B20 temperatures > > DS2423 Counter > > If I look at Bus/stats/errors I see no CRC8 errors out of 217 tries, > however am getting 30% error rate on the CRC16. Just started the system > back up as I did an upgrade to 2.8p14 and I see 39 tries and 14 errors > for the CRC16. > > What devices use CRC16 ver CRC8. ? Running "grep CRC *c" from within module/owlib/src/c/ should give you a a good idea of what devices use CRCs. After a quick check, it seems like the DS18x20 sends a CRC8 when the scratchpad is read, and the 2423 uses a CRC16 in some operation. The HobbyBoards devices (driver in ow_eeef.c) do not seem to use CRCs for anything. The HobbyBoards hubs are based on the 2409, which does not seem to use CRCs. > What do others people get in terms of errors on their > bus.0/statistics/errors ? In one bus with only 12 DS18B20s (I'd say this bus has a decent long run), I currently see 0 errors in 111534 CRC8 tries (no CRC16 tries in this bus). On another bus with 2 custom, microcontroller-based devices and 2 DS18B20s, I see 143/10276 CRC16s and 215/14004 CRC8s. This does not mean anything, though, since those errors are caused by bugs in my firmware and not because of physical/electrical problems with the bus. In your case, I think the bottom line is that since you are seeing some CRC errors, there is likely some physical/electrical problem with your wiring or bus. Cheers, Eloy Paris.- ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
