Hi,
I can successfully read a GPIO Pin on the RasPi if I do it like: |value| dataFile ensureOpen. value := dataFile upToEnd. dataFile close. ^value
dataFile is the /sys/class/gpio/gpioxx/value file that exists after exporting gpioxx.
Without the reopening and closing of the file I get '' on subsequent reads which means that StandartFileStream>>basicNext answers nil.
Is there a way to get the values without having to close and reopen the file each time?
Thanks
Herbert
Is there a StandardFileStream>>reset?
Michael
On Wed, Jan 28, 2015 at 7:45 AM, Herbert König herbertkoenig@gmx.net wrote:
Hi,
I can successfully read a GPIO Pin on the RasPi if I do it like: |value| dataFile ensureOpen. value := dataFile upToEnd. dataFile close. ^value
dataFile is the /sys/class/gpio/gpioxx/value file that exists after exporting gpioxx.
Without the reopening and closing of the file I get '' on subsequent reads which means that StandartFileStream>>basicNext answers nil.
Is there a way to get the values without having to close and reopen the file each time?
Thanks
Herbert _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Wonderful, dataFile reset. ^dataFile upToEnd
I thought every read request would just produce a new value.
Thanks,
Herbert
does the trick Am 28.01.2015 um 14:13 schrieb Michael Rice:
Is there a StandardFileStream>>reset?
Michael
On Wed, Jan 28, 2015 at 7:45 AM, Herbert König <herbertkoenig@gmx.net mailto:herbertkoenig@gmx.net> wrote:
Hi, I can successfully read a GPIO Pin on the RasPi if I do it like: |value| dataFile ensureOpen. value := dataFile upToEnd. dataFile close. ^value dataFile is the /sys/class/gpio/gpioxx/value file that exists after exporting gpioxx. Without the reopening and closing of the file I get '' on subsequent reads which means that StandartFileStream>>basicNext answers nil. Is there a way to get the values without having to close and reopen the file each time? Thanks Herbert _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org <mailto:Beginners@lists.squeakfoundation.org> http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
How about sending #reset to set the stream back to the start ?
Read the paragraph above "lseek" here... http://falsinsoft.blogspot.com.au/2012/11/access-gpio-from-linux-user-space....
cheers -ben
On Wed, Jan 28, 2015 at 8:45 PM, Herbert König herbertkoenig@gmx.net wrote:
Hi,
I can successfully read a GPIO Pin on the RasPi if I do it like: |value| dataFile ensureOpen. value := dataFile upToEnd. dataFile close. ^value
dataFile is the /sys/class/gpio/gpioxx/value file that exists after exporting gpioxx.
Without the reopening and closing of the file I get '' on subsequent reads which means that StandartFileStream>>basicNext answers nil.
Is there a way to get the values without having to close and reopen the file each time?
Thanks
Herbert _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
beginners@lists.squeakfoundation.org