hollymcr
Posts: 15
Joined: Thu Feb 11, 2016 7:15 pm

1-wire devices not being removed

Thu Feb 11, 2016 7:23 pm

I'm running Raspbian 2012-02-09, and I'm trying to detect the presence (or otherwise) of Dallas iButton devices.

I have set dtoverlay=w1-gpio in /boot/config.txt and sure enough if I put the iButton next to the reader (and wait 10s for it to be scanned) I can see the device:

Code: Select all

$cat /sys/devices/w1_bus_master1/w1_master_slaves
01-0a0d009c7321
However when I remove the device and wait for the next scan the entry doesn't disappear.

I can force its removal by writing 01-0a0d009c7321 to cat /sys/devices/w1_bus_master1/w1_master_remove but that defeats the point of the auto scan.

I haven't played with iButton for a while but last time I did (many months ago) I didn't have this problem.

hollymcr
Posts: 15
Joined: Thu Feb 11, 2016 7:15 pm

Re: 1-wire devices not being removed

Thu Feb 11, 2016 9:48 pm

Minor correction to earlier post: it turns out that the removal is happening but not on the next scan, it can be several minutes.

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