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ms08233
17 Posts |
 Posted - 18 Sep 2002 : 17:53:05
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| I set the clock with Date/Time Properties, but after reset it always goes back to Noon on June 1, 1999! Is there some way to permanently set the clock, or do I have a bad clock battery on my new GC+ development system? |
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briano
18 Posts |
Posted - 18 Sep 2002 : 18:14:56
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Ya, my GraphicsMaster doesn't keep track of time
very well at all.
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ctacke
877 Posts |
Posted - 18 Sep 2002 : 18:32:06
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When you reset or power off your device, the processor gets reset. This in turn resets the clock to the default start date (June 1, 1999).
The device doesn't have a built-in clock battery like a PC or a commercial PDA. If you want the time to persist, you need to add a back-up battery to your system yourself (see section 3.7.3 od the GC+ manual).
Even with a backup battery, keep in mind that, unlike a commercial PDA, the reset button on the board is still a hard-reset (right to the processor). You can do a soft reset by calling restart.exe or put the device to sleep (comparable to the power button on a PDA) by using Suspend from the Start button.
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Chris Tacke, eMVP
Applied Data Support |
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briano
18 Posts |
Posted - 18 Sep 2002 : 18:41:57
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| Now if only I knew how to take this thing out of suspend mode. |
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ms08233
17 Posts |
Posted - 18 Sep 2002 : 18:46:31
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I'm not sure what your warning about hard reset means, but here's our situation:
Our 40 lb device (of which the ADS is a only a small part) runs strictly off wall power (it has several motors that draw a lot of current). It is expected to be turned off when not in use (usually at night). They will just hit the power switch - NOT put it in some "sleep" mode. We weren't planning on have any batteries, but we do want the clock to keep running! Can we hookup a typical button type battery? 2.2 mA sounds like a lot for a tiny battery.
I see the battery also powers RAM, so does that mean we'd no longer have to worry about losing stuff we put in RAM?
Edited by - ms08233 on 09/18/2002 19:10:34
Edited by - ms08233 on 09/18/2002 19:22:43 |
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akidder
1519 Posts |
Posted - 18 Sep 2002 : 19:15:49
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Hi guys. If you want the real-time clock to be preserved, you'll need to supply a backup power source (eg. Vperm) to your system. When you put the system to sleep and pull main power, Vperm will maintain the system RTC and keep RAM refreshed.
To put your GC+ system to sleep, either select Suspend from the Start menu or short the pins of J1 together briefly. To wake a system, again short the pins of J1 briefly.
If you only need to maintain the real-time clock and don't care about the contents of RAM or cold booting your system, consider ordering one of the upcoming rev D or E GC+ systems. These are available in limited, pre-production quantities at this time. This update to the GC Plus adds a real-time-clock circuit independent of the StrongARM. A small coin cell on the new J21 connector will maintain the RTC for 3-10 years. This new solution from ADS significantly simplifies backup power supply for many application.
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Drew Kidder
ADS Technology Transfer |
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ms08233
17 Posts |
Posted - 18 Sep 2002 : 19:26:58
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As I said, our customers won't be putting anything in "sleep" mode - they'll just be yanking the main power switch. Will the battery still keep the clock going in this case?
The newer rev boards sound lovely, but for now, with the board we currently have, how big a battery does this require? |
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ms08233
17 Posts |
Posted - 20 Sep 2002 : 16:27:56
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| OK, we tested with a power supply on J3 and pulled the main power, but that doesn't seem to keep the clock running. We did find that breaking into the Vperm wire on J5 and using a 9V battery does seem to keep the clock running when power is killed. Is this the right way? How long do you think a 9V battery will last? |
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pdombrowski
10 Posts |
Posted - 23 Sep 2002 : 08:26:21
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As Drew mentioned above, it is a requirement to first put the GC+ into sleep mode prior to removing the input 5V supply. The VPERM (typical 5-12V) must always be present. While in the sleep mode the SDRAM contents are maintained and the SA1110 RTC continues to run. Typically, if the input 5V decays from loss of input power, there is just not enough time to properly enter the sleep mode, therefore when power is reapplied the system cannot detect its pre-sleep state. This results in a system reset. The best way to address this is to use the hardware input signal to put the GC+ into sleep state when power loss is detected. A backup battery can be used on VPERM since this input is regulated to 3.3V to maintain the CPU RTC. Depending on the SDRAM configuration, the sleep mode current ranges between 2.5-3.5mA. When power is restored the same hardware input can be used to wake up the GC+ and resume operation.
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superiorcontrols
25 Posts |
Posted - 04 Feb 2003 : 18:00:40
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Drew,
How do I tell if my GC+'s are "one of the upcoming rev D or E GC+ systems"? Thanks! |
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akidder
1519 Posts |
Posted - 04 Feb 2003 : 18:07:00
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| Hi ya. The revision of your system board is printed on the underside of the board in the copper. It's the last character of the PWB id number, "170110-8000x". |
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steve
28 Posts |
Posted - 02 Apr 2003 : 10:48:03
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How does this relate to Bitsy+ boards? We're in the same situation, requiring the clock to be saved, but losing power without shutting down, in most cases.
Thanks,
-Steve |
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ctacke
877 Posts |
Posted - 02 Apr 2003 : 10:52:40
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| The BitsyPlus has a separate real time clock (RTC). As long as it is powered, the time will stay current. Keep in mind that the battery for the RTC is on the personality board, so if you are not using a personality board or are using a custom one, you must add power for the RTC. |
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steve
28 Posts |
Posted - 02 Apr 2003 : 11:08:52
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Yes, I realized that right after posting the message, that we have the RTC, and we did incorporate the battery into our design. I have verified that the clock is keeping time, but now I need to find a way to set that clock from an eVB program. (As asked in the eVB forum)
Thanks,
-Steve |
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whuh
23 Posts |
Posted - 02 Apr 2003 : 12:27:12
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Hi Steve,
Regular API, SetLocalTime() sets system clock and RTC. |
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david
2 Posts |
Posted - 27 May 2003 : 18:14:14
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| Does anyone know which polarity to use for the battery terminals connecting to J21? Does it matter? |
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akidder
1519 Posts |
Posted - 28 May 2003 : 15:54:35
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| Hi David: We've updated information about the GC Plus RTC circuit at topic 202. Polarity IS important! |
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How do I "persist" the date/time?
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