From: VaibhavGhadiok <vai...@gm...> - 2010-05-24 03:27:17
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Most people do connect the Xbee Din and Dout lines directly to the micro-controllers. I have used them before as well. None the less, this might well be the problem. I use this module: http://www.sparkfun.com/commerce/product_info.php?products_id=9132 This is what Sparkfun people have to say: This board comes fully populated with 3.3V regulator (16V max input), XBee socket, four status LEDs, and a diode to allow 5V systems to communicate safely with the 3.3V XBees. I believe for data-in, if the 5v line goes low it pulls the data-in pin behind the ordinary diode also to low. And the xbee is protected from the 5v by that same diode. But how do you get data-out from 3.3 upto 5V? And also I connect my Zigbee module to pins 46, 47 (Rx, Tx of STUART) of the Gumstix and to the Vcc and Gnd pins that are adjacent to these pins (in the same row). So, there is a common ground that is shared. I will 0-scope it tom. Dave Hylands wrote: > > Hi Vaibhav, > > On Sun, May 23, 2010 at 6:02 PM, VaibhavGhadiok > <vai...@gm...> wrote: >> >> There are no fluorescent lights. Only light bulbs. The amount of garbage >> data >> b touching the Rx pin is quite a lot. It just streams across the screen. >> I >> am not sure if EMI could be attributed. I seriously don't know. > > I wouldn't worry about getting noise on the Rx line when you touch it > and its not connected to anything else. > >> The Zigbee module does work at 3.3 V. I have a Regulator to give me 3.3 V >> from 5 V. > > You'll need a 3.3v to 5v converter between the robostix and the Zigbee > module. > >> Another possibility, I have all the three boards stuck together (Verdex >> Pro, >> Netpro, robostix). But there might not be a way to test the boards by >> removing them. I will not be able to attach the robostix board to the >> gumstix if I use a tweener board until and unless there is a way to >> access >> STUART using the Tweener board. > > Personally, I wouldn't bother with the tweener. > > If you can connect the Tx and Rx together on the robostix, and sertest > works (and you're seeing what you type) then the robostix is working. > > You'll need a voltage converter and you need to make sure that ground > is connected through from the robostix to the voltage converter to the > ZigBee. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------------ > > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://old.nabble.com/Noise-on-Rx-pin-of-ttyS2-%28STUART%29-tp28647788p28653438.html Sent from the Gumstix mailing list archive at Nabble.com. |