On 21 September 2011 22:04, p4trykx <[email protected]> wrote: > Dnia 21-09-2011 o 20:30:29 Colin Law <[email protected]> napisał(a): > >> >> I don't know whether the first messages indicate a problem but it >> appears that I am not able to talk to the DS9097. > > I think those first errors doesn't matter. > There with read timeout are relevant.
Right, I have got to the bottom of the problem, which I will describe in detail in case anyone finds this thread and so does not fall into the same trap as I have. I am providing the serial ports using the method from Rod Whitby [1] which uses a modified AD233BK board from Compsys [2] to provide two serial ports for the wrt54G. /dev/ttyS0 for the console and /dev/ttyS1 as a general purpose port. Rod's instructions include details of how to wire the board to the connector on the router. In particular ttyS1 rx and tx have to go to points on the board labelled Ct and Rt. Unfortunately it appears that the labelling on the board has changed since Rod did his instructions and the labelling of those two points has been swapped. The copper does not appear to have changed, just the labels. I therefore had tx and rx swapped at the connection to the router, so not surprisingly it did not work. I will let Rod know about this problem. Having swapped them over the serial port started working. > ... > >> One issue I am unsure about is what do do with DTR and RTS (these are >> not present on the serial ports). Looking at the data sheets for the > > The power is stolen from those lines. I think that +6v (instead of -6V) on > one of those pins should be enough. I'm a self taught electronic(I have > many holes in knowledge) so I might be wrong but form what I see on the > schematics the diode passed though positive voltage from one of those pins > to the regulator. > Look here. > http://pl.wikipedia.org/w/index.php?title=Plik:Diode-IV-Curve.svg&filetimestamp=20110422040516 > http://datasheets.maxim-ic.com/en/ds/DS9097U-DS9097U-S09.pdf > > From where do you get those 6V? Is it from MAX232? It might be not enough > to power the adapter. Does Your WRT54G has 12V power adapter. I see you are right there, I had tried it with +6 previously, but of course it did not work due to the problems above. Having fixed those problems and reverted to +6v picked up from the max233 (actually it is a Sipex sp233AEP) the DS9097 is now working and I can access the bus ok (at least with one DS18B20). Great. I can now tell you that it is 18 deg C in my greenhouse :) Hopefully the 6V from the 233 continues to provide sufficient power as I extend the bus. The power to the router is nominally 12V but I measured it at 16V (under load). The 233 is speced at 12V max on RTS, but if necessary I can drop it down. Hopefully I won't have to. Once again, thanks for the help. Colin [1] http://www.rwhitby.net/projects/wrt54gs [2] http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html -- gplus.to/clanlaw ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2dcopy1 _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
