> >> I don't think this is too useful because one had to rewrite every > >> single needed I?C slave driver out there for this crude interface > >> and of course the tools, too. These drivers and tools do exist. > >> Why reinvent the wheel? > > > > I totally agree, as long as you want to teach me or point me to a > > good tutorial on how to use this weel... ;) > > > Load the I?C core and I?C hostadapter kernel module where your hardware > is connected to. In case of the DS28E17, it would be the proposed (yet > not existing) i2c-w1 and w1-ds28e17 modules. It gives you another I?C > bus e.g i2c-6. > > Then load the kernel module for the I?C slave chip you like to use. E.g > if you have an I?C portexpander like the pca95xx series and compatibles, > load the gpio-pca953x module. Then register the chip on the DS28E17 I?C bus: > > # echo pca9554 0x3C >/sys/bus/i2c/devices/i2c-6/new_device > > given the chip address is 0x3c on that bus. The kernel then gives you an > additional GPIO chip accessible through /sys/class/gpio, e.g. > /sys/class/gpio/gpiochip248. With > > # echo 249 >/sys/class/gpio/export > > you export pin 1 of that chip to sysfs (as the new GPIOs may be used by > another kernel functionality if you don't do that). By doing > > # echo out >/sys/class/gpio/gpio249/direction > > it's an output, and by > > # echo 1 >/sys/class/gpio/gpio249/value > > you can control the output value. Actually, any GPIO tutorial you find > for the Raspi, Beagleboard or such applies. > > > For sensor chips it's even simpler, their properties appear in > /sys/class/hwmon as soon as the driver module is loaded and the chip is > registered on the I?C bus. > > > > > > I think I got th idea - very nice again - but I would need more > > docu/tutorial/background about this. I never used I2C chips this way > > (used them the "arduino" way) - sounds extremely useful! :) > > > Well, see above. The whole magic is registering the chip on the I?C bus > ot is on so the kernel driver can find it. You can then use its > functionality through all the abstractions the kernel gives you, e.g. sysfs.
Thanks a lot for this useful summary! I think I got the main points now. Next step then is to use a user written /usr/bin/owgpio in the owfs externals config and this script accesses /sys/class/gpio/gpiochip248, as you described earlier, right? > > Ball-grid arrays are quite common today so I have to ask what you > > consider a *professional* company? ;) What was the issue? Did the > > use a reflow oven? What about vapour phase soldering? Given that > > Maxim released this package only I would guess they are quite > > confident about this. BUT I agree it is not optimal. (ps: solder = > > leaded solder ... what else?! ;)) > > > Sure. I think it's not possible to half-solder a chip without using an > oven. I've tried half-a-dozen companies which labelled themselves as > "professional" but they don't even get to place chips on prototypes all > in the right direction. What do you learn about that: You need to do all Ok, but I would call such a company pseudo professional at most. That's a pitty. > in the right direction. What do you learn about that: You need to do all > that stuff yourself if you want to look your your own errors instead of > looking for theirs. This is - in general - a very good statement. I think it's wise, fair and safe to follow this all the time. > >> Have to read and try a lot there. If you manage to put the DS28E17 > >> on a breakout board and send it to me, I could spare the cost for > >> the evaluation kit. Where are you located? > > > > Switzerland. Actually here everything is expensive, but I would be > > willing to spend the money (about 50?) if you give me your address. > > > Nah, I will buy the kit myself then. Ok, I'm fine with this if you are! > >> The most horrifing thing that would happen in real life is they > >> send Matthias and/or me a letter we should stop it. And that's when > >> I, in all kindness, would ask "Are you serious? But you do > >> understand you got the Linux driver for your chip for free just > >> because we did this." > > > > This is intressting... Do you know of anybody that happened to? I > > know the story of dvddecrypter only - but I guess this is not > > comparable since its software... > > > Ahh, that's Hollywood. They are just crazy. Too much cocaine. No > reasonable thoughts coming from such persons. ;)))) - nothing to add except for; I agree! ;)) > >> As written above, you get that as a free gift as soon the kernel > >> driver creates an /dev/i2c-... device for the DS28E17 I?C > >> interface. > > > > Honestly I think that would be REALLY cool! Wireless 1wire for short > > distances only would allow to cross glass windows and go outside > > (weather station, etc.) without any issue... ;) > > > I think so. However, as it's onewire tunneled through onewire, it would > be extra-slow, I think. Possible - but this useful to a lot of stuff - of course depends on the number of slaves on the other side. Let's see then, just proceed step by step. :) Thanks a lot! Greetings! ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
