Hi Pascal,
I think that those delays are caused by older kernel. There is kernel
2.6.20.4 on my board.
I was testing owfs 2.8p4 but it is design for kernel 2.6.29+ Am I right?
I cross compile owfs 2.7p34 and it works faster and more stable. Reading
switch PIO about 600ms and temperature about 900ms-1,5s.
My application in Java is reading from owserver and timing is similar.
I'm using jowfsclient library.
Yes, I'm using hardware i2c controller, so my owserver is connecting via
/dev/i2c-0:0 (0x18).
You are right, reading temperature after writing a simultaneous converT
command is faster. What is more... I find out that writing converT
command receiving errors at owfs 2.8p4(with 2.7p34 works perfectly).
Roman
W dniu 03.02.2011 21:44, Pascal Baerten pisze:
> Hi Roman,
>
> I'm using owfs with ds2482-800 and found the communication slower than
> other bus masters solutions.
> However not that slow than you describe.
>
> Analysing 1-Wire communication with a digital scope shown that an idle
> period is visible between each byte and "tri-bits".
> This idle period is around 1,3ms for my system (nslu2 with debian),
> this reduce the effective throughput to 4kbit/s instead of 15kbit/s.
>
> Do you have an hadware assited i2c controller embedded or are you
> using software i2c?
> I think that my behaviour come from software i2c that does not buffer
> transactions and require attention from owfs between each byte and
> tri-bits.
>
> Regarding the temp reading, I think you better to read 'temperature'
> property after a simultaneous converT command instead of 'fasttemp'
> which is not prepared by the simultaneou command. - Paul correct me if
> not true -
>
> You may also find usefull information by starting your owfs daemon
> with '--debug' param. Reading temp involve a blocking transaction that
> wait until conversion is finished by polling 1-wire or for fixed time
> depending on method used and parasite power mode.
>
> Pascal
>
>
>
> 2011/2/3 "Roman Jałoza - TechBase Sp. z o.o." <[email protected]
> <mailto:[email protected]>>
>
> Hi,
>
> I'm developing 1-wire communication at embedded computer with ARM9
> and ds2482-100 master chip.
> Is anyone test owfs performance via i2c master?
>
> I'm reading temperature from ds18b20 sensors and it took a long
> time (from 1,5s to 8s) with fasttemp read. It should be much
> faster. I've made some tests with writing simultaneous/temperature
> bit but performance was still the same - means poor.
>
> Reading PIO states from ds2408 device took about 600ms (but
> sometimes 1,5s).
>
> Devices are powered (reading with parasite mode took 5-8s).
>
> Is anyone have some idea? some solution?
>
> --
>
> Best Regards * *
>
> *Roman Jałoza*
> //
>
>
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> --
> Pascal
> www.brain4home.eu <http://www.brain4home.eu>
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and provide services. The best practices for maximizing a physical server's
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