I've got an EM406 happliy working on a circuit board talking directly to a PIC 16LF88. Not a problem at all on at least 10 different EM406 modules. Today, I assembled a few more using a NEW batch of EM406A's that I just got direct from USglobalsat. NONE of them work -- all just send garbled data.
I take a board and an EM406 that works, swap out the EM406 for a new one, and it fails. Just garbled data. It does blink, indicating that it's locked, and that (garbled) data coming out seems to be about once per second. I then take the good unit, and connect via a MAX232 to hyperterm. Good data -- now swap in the new one -- garbled.
Ideas? Comments? Suggestions?
GPS is running off of 5V bench supply. NMEA is expected at 4800 baud. EM406 Input pin is tied high. SirfDemo can't synchronize protocal/baud rate.