PA> Perhaps I chose the wrong polarity when first designing the PIO interface. The PA> thought is when the PIO is "on" as a switch, it is conducting and an LED (for PA> instance) will light. Of course it is conducting to ground, and so the sensed PA> voltage will be ground (zero) rather that Vdd (5V=logical 1) which can be PA> confusing. It doesn't help that the internal 1-wire connand for conducting is PA> to set the bit 0. It does's not matter what caused the such a misunderstanding. Important thing is you can add more detailed description (explaining) to the OWFS web pages.
Now it is more than sure: Logical 0 sent to the PIO gives logical 1 (TTL 5V) on the DS2408 data pin. So the logical value sent to the PIO is INVERTED!!!! PA> Sorry about your lost day. I can't replace it. I didn't mean it to offend you. Sorry if it looks like (I am not a native English speaker). It was just a note. I am more than happy if my experiments (my time) can help to OWFS community and to your great work. :))) Petr PA> Paul PA> On Monday 03 October 2005 05:08 pm, Petr wrote: >> Thanks to the "Owfs and DS2413 -- SOLVED" topic on this list, the >> problem is solved and I am able to initialize the LCD display >> flawlessly. >> >> My feeling was I have to send (write) "1" to the PIO if I need to get >> "1" (HI, 5V) on the DS2408 data pin. Opposite is the truth. >> >> For example if you write: >> PIO_ALL="1,1,1,1,1,1,1,1," >> >> you will get LO TTL logic level on the all data pins of the DS2408. >> >> It took me the whole day to get it working :) >> >> Petr >> >> PJ> Simon Natterer <simon <at> natterer-legau.de> writes: >> >> Paul Alfille wrote: >> >> >In short, the datasheet is confusign to me. I gather there is a mode >> >> >where the DS2408 is used for relatively high-speed communication >> >> > through it's PIO pins, with the strobe pin used for handshaking. This >> >> > fits poorly into the OWFS model. OWFS pretends the 1-wire devices are >> >> > block-devices (think of 1-wire as a scsi controller), not a character >> >> > devices (like a serial line). >> >> >> >> It seems to work for me! The RSTZ pin signals correctly >> >> when the written data is valid, for me it is connected to >> >> the display-enable-pin and the display works. So I think >> >> the RSTZ pin generates a falling edge after each >> >> byte is written. >> >> So if in owfs strobe is set to 1 it has this behavoir, if it >> >> is set to 0 the RSTZ pin is used as a reset pin. >> >> I don't see a problem. >> >> PJ> Simon, >> >> PJ> I am trying to experiment with DS2408 to drive LCD display. I am trying >> to write PJ> the code in OWPython binding. But I can't even initialize the >> LCD display. Can PJ> you post the snippet of the LCD initialization code >> please? >> >> PJ> Thanks a lot >> >> PJ> Petr >> >> >> >> PJ> ------------------------------------------------------- >> PJ> This SF.Net email is sponsored by: >> PJ> Power Architecture Resource Center: Free content, downloads, >> discussions, PJ> and more. http://solutions.newsforge.com/ibmarch.tmpl >> PJ> _______________________________________________ >> PJ> Owfs-developers mailing list >> PJ> [email protected] >> PJ> https://lists.sourceforge.net/lists/listinfo/owfs-developers >> >> >> >> ------------------------------------------------------- >> This SF.Net email is sponsored by: >> Power Architecture Resource Center: Free content, downloads, discussions, >> and more. http://solutions.newsforge.com/ibmarch.tmpl >> _______________________________________________ >> Owfs-developers mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/owfs-developers PA> ------------------------------------------------------- PA> This SF.Net email is sponsored by: PA> Power Architecture Resource Center: Free content, downloads, discussions, PA> and more. http://solutions.newsforge.com/ibmarch.tmpl PA> _______________________________________________ PA> Owfs-developers mailing list PA> [email protected] PA> https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
