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akidder
1519 Posts |
 Posted - 28 May 2002 : 14:43:23
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Q: How can I prevent the Graphics Master (and other products) from going to sleep during a power failure or momentary power interruptions?
Revision C of the Graphics Master adds a supercapacitor option. This feature gives the system time to go to sleep before power fails entirely. While this feature is useful in end user applications, it can become a nuisance when you want to fully power-cycle a system during product development.
To prevent the system from going to sleep in a power failure event, set the registry key in ADSLOAD.REG as follows:
[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Power]
"VddPwrOffFromApps"=dword:1 |
This entry tells the ADS power management drivers that your application will take care of a power failure when it occurs. By not handling that event during a power failure, the system will drain the super caps before failing.
For more details about this and other reigstry keys, take a look at the full ADSLOAD.REG file for the Graphics Master.
-----------------------
Drew Kidder
ADS Technology Transfer
Edited by akidder 11-Jul-2003: Mention other products in post. |
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akidder
1519 Posts |
Posted - 07 May 2003 : 16:00:55
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Here's an excerpt from GMaster adsload.reg file 700110-9717A about trapping the power failure event:
;---------------------------------------------------------------------
; Power Management: Trap power failures
;
; This registry entry allows your application to get notification
; when a power failure has occurred. Normally, the system goes
; immediately to sleep when it detects a power failure. This
; corresponds to setting this key to "0".
;
; If you want your application to have a particular behavior during
; a power failure, you can set this key to "1" and trap the
; VDDPWROFF event yourself. When you've completed application
; cleanup, issue the VK_OFF keyboard event to go to sleep.
;
; Warning! Your power supply must be able to hold up the 5V power
; long enough to handle your functions and put the system to sleep.
; The Graphics Master needs a minimum of 200ms to go to sleep.
; The supercapacitor circuit on the Rev C Graphics Master works for
; immediate shutdowns, but test carefully if you think your appplication
; will take a long time before going to sleep.
;
; Availability: Graphics Master CE builds 3.18 and later
;---------------------------------------------------------------------
[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Power]
"VddPwrOffFromApps"=dword:0 ; 0 sleep on power fail, 1 issue event "VDDPWROFF"
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akidder
1519 Posts |
Posted - 11 Jul 2003 : 11:16:08
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This registry key also works with other products that have power failure detection, like the Bitsy Plus and BitsyX.
Bitsy products have the advantage of being able to detect power failures earlier, so have more "head room" for shutting down than the Graphics Master.
For further reading about power management, see the CE power management topic index.
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kurtwl
28 Posts |
Posted - 30 Mar 2005 : 11:16:31
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With an ADS BitsyX Windows CE Ver 4.20.08, the entry
[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Power]
"VddPwrOffFromApps"=
does not exist, but
[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Power]
"PowerOffFromApps"=
does.
Are these the same thing, will setting either/both to 1 end with
"VDDPWROFF" being issued [or is that now called "POWEROFF"]?
When did it change? Is it likely to be renamed again?
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jjoseph
47 Posts |
Posted - 16 Oct 2006 : 16:00:33
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This post is just to round out this thread.
VddPwrOffFromApps is the current registry key. To use the power off trap on Bitsy products, put this key in your ADSLOAD.REG file as described at the beginning of this thread.
PowerOffFromApps and PowerOffByGPIO1 are deprecated keys (no longer to be used).
VDDPWROFF is still the correct event.
The SleepIntercept Sample Application (Topic 1292) demonstrates the behavior of this feature.
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ctacke
877 Posts |
Posted - 05 Aug 2008 : 13:28:35
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| Since "PowerOffFromApps and PowerOffByGPIO1 are deprecated keys" might I suggest maybe removing them from the default registries in current platforms to prevent confusion? It's not obvious that they're deprecated (unless you find this specific Forum Topic) and though deprecated they still seem to work (at least on the image I'm testing). |
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cbadr
154 Posts |
Posted - 07 Aug 2008 : 15:38:47
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| PowerOffFromApps is still supported for backward compatibility. On newer builds, either VDDPowerOffFromApps or PowerOffFromApps would work. We will take your suggestion into account in future releases to remove the PowerOffByGPIO1 as it is not used anymore. Thank you. |
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