MediaTek lock ups

Has anyone else had their MediaTek GPS lock up, refuse commands, and send unrecognizable garbage?

While working to track down the "longitude error when in binary mode" bug, I noticed that my GPS would suddenly stop sending NMEA text messages and send garbage. Cycling the power sometimes fixed it. Letting it sit a while sometimes fixed it. Usually it took several tries to get it going again. 

Symptom #2 is that instead of blinking at 1Hz (while trying to lock) or being solid on, the blue LED on the GPS will blink much slower. I'd say 0.5 Hz.

Symptoms are the same when working on a PC or a Mac, using a 3V or a 5v FTDI cable. Affect both my MediaTeks.

Anyone else? 

And a ps to Jordi: You may have a battery issue or a battery killing process issue. When I started seeing this I checked the back up battery voltage, one GPS was just 0.17 volts, the other was 2.97 volts. These units arrived less than a week ago. 

I pulled the dead battery and ran a jumper from pin 1 (Vcc) to pin 4 (Vbackup) since the docs say in red that Vbackup must be present. That unit "resets" sooner than the unit with a battery, but also fails faster.

Here is a trimmed log of the output, right at the point where it locks up.

$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,232523.422,V,,,,,0.00,0.00,210810,,,N*44
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,232524.422,,,,,0,0,,,M,,M,,*4C
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,232524.422,V,,,,,0.00,0.00,210810,,,N*43
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,232525.422,,,,,0,0,,,M,,M,,*4D
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,232525.422,V,,,,,0.00,0.00,210810,,,N*42
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
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  • Hi, my name is Enrico an i'm writing from Rome, Italy. I'm a new user.
    Several days ago i bougth from DIYStores a pcb called "MediaTek MT3229 adapter" ( http://store.diydrones.com/product_p/br-0014-01.htm )
    It's the same pcb you used, but over mine i did soldered a GTOP FGPMMOPA6E.
    After the first GPS Fix i get the same error ( correct NMEA followed by strange characters). Now the blue ligth blink dimly, no way to receive prompt, no answer all. I tryed every speed and COM setup.
    Any other suggestion ?
    I'm sorry for my bad English,
    Tks, Enrico.
  • Developer
    Hi there,

    If you have faulty GPS return it! Just contact sales@storediydrones com and ask for RMA because your GPS is not working properly...

    There's an issue on the firmware that we correctly working on and you can update it at home.
  • It also happens whether the unit has a fix or is still acquiring satellites.
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