EM401 unhappy

Tips and questions relating to the GPS modules from SFE
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carterson2
Posts: 20
Joined: Mon Nov 27, 2006 8:25 am
Location: memphis
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EM401 unhappy

Post by carterson2 » Mon Nov 27, 2006 8:44 am

My Em401 seemed to quit sending.

Pin6(vcc) has 5v,
Pin5(tx) has nothing (just sits at +3v, dead)
Pin4(rx) on scope shows good RS232 signal coming in when I type using teraterm.
Pin3(/reset) I connected this to gnd momentarily to try resetting it, but didnt help.
Pin2(gnd) hasn't changed
Pin1(gnd) hasn't changed.

The EM401 is connected to a Eval-EM406-RS232 which I wired to work. It has worked great for 2 months in my car. Then it just stopped sending...

No matter what I do, I never see anything come out. Even connecting pin3 to gnd, didnt cause any garbage to show up on teraterm (hyperterm). At 4800, I sent it $PSRF100,1,9600,8,1,0*0C to change speed to 9600, but that didnt do anything.

Q: Can I perhaps unhook the battery somehow and get it to hard-reset somehow???

Thanks for any leads,
jim pruett

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ohararp
Posts: 263
Joined: Sun May 01, 2005 8:43 pm
Location: Dayton, OH
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Post by ohararp » Tue Nov 28, 2006 8:23 am

Jim,

Isounds like the MAX23X rs232 chip on your dev board may have died. I had a similar inexplicable problem.

Ryan
Regards Ryan :-)
$25 SMT Kapton Stencils - http://www.ohararp.com/
US Distributor of PDS - http://www.ohararp.com/compilers.html

carterson2
Posts: 20
Joined: Mon Nov 27, 2006 8:25 am
Location: memphis
Contact:

Post by carterson2 » Tue Nov 28, 2006 8:33 am

I called usglobalsat and they think their chipset died. They also say the warrantee is thru sparkfun which is better than if I had for example bought it off ebay in which case they said I would be SOL.

BTW, I connected pin 5,6 together to do a loopback which worked.
That eliminated the max chip.

Have fun.
jim

carterson2
Posts: 20
Joined: Mon Nov 27, 2006 8:25 am
Location: memphis
Contact:

Post by carterson2 » Tue Nov 28, 2006 8:34 am

oops, I meant pins4,5.

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