Re: [R-engine-developers] After 2 nights of testing

[Peter M. <pe...@mc...>]

Perhaps I should open up my vaio again and trace the tracks. Yep I'll do
that this weekend and let you know what pins do what.

On Fri, 2005-08-19 at 09:55 +1000, Peter McNeil wrote:
> Two nights is nothing to get frustrated over! You're doing a fine
> Stirling job! The problem here is that there are 256! or 32! possible
> combinations for which GPIO pins do what. They are called General
> Purpose because hardware designers are free to use any pin for anything
> and quite often they select a pin because it makes the PCB layout easier
> not be cause it makes logical pin sense.
> 
> Cheers,
> Peter.
> 
> On Wed, 2005-08-17 at 23:23 +0200, Cedric Cellier wrote:
> > Hello the list !
> > 
> > After 2 nights playing with the GPIO I am disapointed now.
> > First, When you set all pins to inputs and read GPIOREAD, you got 
> > '0xBB'. That is all ones but 2 bits. Ive read on V4Lwiki, and it seams 
> > reasonnable, that the 1 bits are good candidates for outputs.
> > 
> > I then tryed all combinations involving thoses 6 bits for SDA and SCL, 
> > trying to address chip address 0x42 (more probable address of a SAA7114, 
> > considering the SAA7113 was addressed on it's default address too).
> > 
> > None of these combinations give me an ACK after the address was written.
> > 
> > So, I reversed my reasoning and try bits 0x4 and 0x40 alone for SDA and 
> > SCL. This, neither, does not give ACK... except if you clear the bit 6 
> > in what I call the 'Magick 0xC8FFFFCF', that is the 'end of reset' in 
> > the mb86393_reset function that's called first.
> > 
> > I don't know where the 'CF' goes, but as its related to the GPIO I 
> > played with it a bit. The only thing I am certain of, is that if you use 
> > 0x40 for SDA and if you clear bit 0xb0 of this 0xc8ffffcf, then you will 
> > have all the ack you want when reading the sda (?) line.
> > 
> > After two nights, this result is a bit frustrating. :-(
> > 
> > 
> > 
> > -------------------------------------------------------
> > SF.Net email is Sponsored by the Better Software Conference & EXPO
> > September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices
> > Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA
> > Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf
> > _______________________________________________
> > R-engine-developers mailing list
> > R-e...@li...
> > https://lists.sourceforge.net/lists/listinfo/r-engine-developers
-- 
Peter McNeil
http://www.mcneils.net