From: Yuvraj A. <yu...@uc...> - 2008-01-31 19:28:47
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WiFi even in idle mode (i.e. No Tx /RX) takes about 1W. When using Infrastructure mode (i.e. With an Acess Point) there is a possibility to use the WiFi Power Save Mode (PSM) which can reduce the power consumption dramatically although currently the driver is a bit flaky. >From my measurements the power consumption is PSM drops to around 100-150mW. Once you are associated to a WiFi Access Point if you do a : "iwconfig mwlan0 power on" <-- Sets the PSM .or. "iwconfig mwlan0 power off" --> Sets the normal awake mode for WiFi. (Note : change to "wlan0" instead of "mwlan0" for OE builds) One way to tell if the switch worked is that the WiFi yellow LED starts to blink at a really fast rate when the PSM is successful. Although I repeat again, the WiFi driver still needs work. I have documented the WiFi bugs using bugtracker and Steve said he will look at them when he does get a chance! Hope this helps. cheers Yuvraj -----Original Message----- From: gum...@li... [mailto:gum...@li...] On Behalf Of Jay Phillips Sent: Thursday, January 31, 2008 10:31 AM To: 'General mailing list for gumstix users.' Subject: Re: [Gumstix-users] Expansion board power consumption Thanks for those numbers. I'm already tracking sensor draws separately, so the 100mA sounds better than 250mA. Ouch, didn't realize WiFi was so hungry. At some point I'll look into the possibility of shutting off the wired connection to save power since I won't be using it. ----------------------------------------------------- Jay Phillips Tronix LLC - http://tronixllc.com -----Original Message----- From: gum...@li... [mailto:gum...@li...] On Behalf Of Dave Hylands Sent: Thursday, January 31, 2008 10:27 AM To: General mailing list for gumstix users. Subject: Re: [Gumstix-users] Expansion board power consumption Hi Jay, On Jan 31, 2008 10:08 AM, Jay Phillips <jay...@tr...> wrote: > I know that "it depends". I was looking for some "order of magnitude" type > of info. > > I put 250mA in the spreadsheet as a placeholder for now. Same for the > netwifimicro-SD. According to the datasheet for the ATMega128, an idle 8 MHz processor draws 11 mA, and an active one draws 19 mA. They don't give numbers for 16 MHz. So 50-100mA feels like a good number (for the whole robostix board), plus whatever your sensors draw. 250 seems like a reasonable place to start for the netwifimicrosd without a wifi module. With a wifi module, you'll want 600 - 700 mA. > The big current draws are going to be the drive motors, with a locked-shaft > current of 5A. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ gumstix-users mailing list gum...@li... https://lists.sourceforge.net/lists/listinfo/gumstix-users ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ gumstix-users mailing list gum...@li... https://lists.sourceforge.net/lists/listinfo/gumstix-users |