Hi Nick, On 11/29/2011 10:19 AM, nick wrote: > Hi > > I'm working on a custom 1-wire slave (IR sender for some air con > units), and I picked the DS2431 to emulate for exposing a memory mapped > interface to the IR sender. The IR sender (already done) and DS2431 code > is coming together nicely in a 12F683 at 4MHz. The master is a LinkUSB, > which now reports 1.5 for the firmware, so I patched the link driver to > recognise it as a version 1.4 device. > > So far my slave shows up in the file system, and reading data from it > works, though isn't required. I have a problem when implementing the > write scratchpad feature though, as a DS2431 should TX an inverted CRC16 > of the received command, address and data, but there are no read slots > coming from the master for the CRC after it sends the 8 bytes of > scratchpad data. I may have missed something, but I'm not sure what and > would appreciate any pointers. It appears that the CRC would simply > dropped by a slave as it cannot be sent. I also get a CRC error on a > read scratchpad operation at the moment, but that may well be an error > in my slave, though I have the CRC16 algorithm correct and tested.
Have you looked at OWFS' ow_2433.c? That might help. Both the DS2433 and the DS2431 are implemented in ow_2433.c. The 2433 has family code 23 and the 2431 has family code 2D. The function OW_w_2Dpage() is the one that handles writes to the 2431 and, if I am reading it correctly, it never reads the CRC16 after sending the Write Scratchpad command. So this looks like something on the OWFS side and not on your emulated DS2431. Cheers, Eloy Paris.- > > Last, the selection of a DS2431 is arbitrary, and if there's any > recommendation for a different memory oriented part to emulate then the > choice can easily be changed. It just needs to be a part that has about > 8 bytes or so of writeable address space. > > Nick > > ------------------------------------------------------------------------------ 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. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
