1-Wire Dallas 18b20 not working
Rabih Kassab
I got a new 1-wire 18b20 and linked it as described in the article,
but when I put it on the foxG20, the foxG20 card green color start
blinking quickly in green and the borad reset.
any idea please ?
I have the last updated uImage on the foxG20 : Version R18 (LATEST)
-
Kernel 2.6.38 and Debian 'Squeeze' 6.0
Best regards,
Melmoth
On which pin of the foxboard do you plug the data pin of the 1Wire
18B20 ?
In fact it is often written to plug it to J7.5 (for the kernel 2.6.35)
whereas it should be plug to the pin J6.19 (for the kernel 2.6.38).
Let's have a look a the post at the end of this page :
http://groups.google.com/group/netusg20/browse_thread/thread/4b485620d6e8dd53/934bdc3f996ea1be?lnk=gst&q=one+wire+dallas#934bdc3f996ea1be
I broke my head during a long time until I found this.
Melmoth
Rabih Kassab
I actually I am using the newest kernel R18, and I get it connected to
the pin J6.19 as they say for this kernel, but still it did not work.
could you please let me know for those that work how exactly you
connected the 18b20, is it like they describe in the article ? or
there is another way for the new kernel except j6.19 ?
this is really very strange, because when I connect the 18b20 the
green led start blinking fastly it's like a short circuit !!!
please your help
On 1 déc, 22:37, Melmoth <vincent.szyman...@gmail.com> wrote:
> Hello,
>
> On which pin of the foxboard do you plug the data pin of the 1Wire
> 18B20 ?
> In fact it is often written to plug it to J7.5 (for the kernel 2.6.35)
> whereas it should be plug to the pin J6.19 (for the kernel 2.6.38).
>
> Let's have a look a the post at the end of this page :http://groups.google.com/group/netusg20/browse_thread/thread/4b485620...
ThomasV
I have the same problem with Dallas DS18B20:
- Kernel R18 (KERNEL 2.6.38)
- using J6.19 pin with tree wires: GND, DQ (pulled up to VDD with
4k7Ohm), VDD
- downloaded python playground
- I ordered 11.Nov. and received my FOX Board G20 combo box on
24.Nov.11
When I run python scan1w.py it returns error message.
When I check ls -al /sys/bus/w1/devices there is never a file or
folder created for my connected DS18B20 even though it sais that "The
1-wire driver automatically scans each 10 seconds whether new sensors
are plugged on the 1-wire bus. "
I connected the oscilloscope to the J6.19 and also to the formerly
used J7.5. and monitored booting sequence as well as steady state
during normal operation. The voltage remains always high, there is no
sign that kernel is pulling the pin down to start communication on 1-
Wire® bus for min 480usec.
I removed all other devices from DAISY, but no change.
I tried a fresh new microSD with virgin acmesystems kernel, but no
change.
Shall I go back to an older kernel ? Or is something wrong with my
HW?
Thank you for your help,
Thomas
See also:
http://groups.google.com/group/netusg20/browse_thread/thread/427b9356f196ebb1
http://groups.google.com/group/netusg20/browse_thread/thread/4b485620d6e8dd53/934bdc3f996ea1be?lnk=gst&q=one+wire+dallas#934bdc3f996ea1be
Rabih Kassab
ThomasV
Thank you for the help.
I also downgraded to Kernel 2.6.38 R11 and now it works!
Also on the scope I clearly see the communication on pin J6.19 now.
I tested with 12 DS18B20 sensors but only 10 are supported
simultaneously.
I wonder why R18 is not supporting n 1-Wire® bus ?
Best Regards,
Thomas
On Dec 5, 4:23 pm, Rabih Kassab <rabih.kas...@gmail.com> wrote:
> Dear Thomas,
>
> I get this issue solved by reinstalling only the uImage of the first 2.38
> version.
>
> the folder was created and everything was fine.
>
> On Mon, Dec 5, 2011 at 4:52 PM, ThomasV
> <thomas.voglerlar...@googlemail.com>wrote:
> >http://groups.google.com/group/netusg20/browse_thread/thread/427b9356...
>
> >http://groups.google.com/group/netusg20/browse_thread/thread/4b485620...