[ALUG] RTC Alarm Wakeup

[David Reynolds]

Jon,

On 12 Mar 2008, at 12:37 pm, Jon Dye wrote:

>
> On 12/03/2008, David Reynolds <david at reynoldsfamily.org.uk> wrote:  
> Anyone else had any experience of making the ACPI alarm work?
>
> I've got the alarm working on my Mini-ITX M10000.  I have a script  
> called set_alarm.sh which I wrote which contains:
>
> #/bin/bash
>
> if [ "$1" = "--settime" ]; then
>         # convert from seconds since epoc to string
>         date_with_tz=$(awk "BEGIN {print strftime(\"%Y-%m-%d %H:%M:% 
> S %Z\", $2)}")
> else
>         # gnu date can't handle the T
>         gnu_friendly_date=$(echo $* | sed 's/T/ /')
>         # add local timezone
>         date_with_tz=$(date -d "$gnu_friendly_date")
> fi
> # hw clock is in UTC so convert date to UTC
> hw_date=$(echo "$date_with_tz" | date -u -f - +%F\ %T)
> echo "Setting wakeup time to $hw_date UTC"
> echo "$hw_date" > /proc/acpi/alarm
>
>
> You can run this like, "set_alarm.sh 11pm" to set the machine to  
> wake up today at 11pm, or you can specify a full time and date.   
> Basically you can specify anything that the date program understands.
> I also needed to change my shutdown scripts so that when then run  
> hwclock to sync the OS time to the bios it saves and restores the  
> alarm time.  e.g.:
>
> ACPITIME=`cat /proc/acpi/alarm`
> /sbin/hwclock --systohc
> echo "$ACPITIME" > /procacpi/alarm
>
> This is a known problem with my motherboard and now I've done that  
> it all works for me and I'm using it to shut down my tv machine  
> which runs mythtv and wake it up in time to start recording the  
> next program.  I think I originally got the instructions from here  
> http://www.mythtv.org/wiki/index.php/ACPI_Wakeup


I'm pleased to say that this works perfectly - thanks Jon.

-- 
David Reynolds
david at reynoldsfamily.org.uk