MTK GPS stuck in NMEA mode?

I'm setting up a new ArduPilot+ArduIMU for the first time.

I have the DIYDronesMediaTek MT3329 GPS, and my understanding was that it already has the custom firmware for MTK binary protocol.

When I build the arduimu code (version 1.7), it only works if I set GPS_PROTOCOL to 1 (NMEA).
If I use 4 (MediaTek), then no GPS lock is present, no GPS debug data, no blue LED, etc.

I have questions:

1) Do I have to load firmware onto the MTK GPS, or is it pre-programmed?  I see the instructions for how to load the firmware, but not how to hook it up.   Can the Ardupilot Shield be used to break out the signals for programming via FTDI cable?

2) Do I have to send a special command to the GPS to switch it from NMEA to Binary?  Is that something the ArduIMU code should do, or something non-volatile that I have to do once from a serial test program?  Likewise for selected baud rate.

3) What is the baud rate of the binary protocol (to tell the ArduPilot and XBees to match)?

4) Is there a reason to prefer MTK Binary over NMEA, or are they both just as well?

A lot of questions, I know..  Thanks!

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  • Hi Chris,

    Did you manage to release zip file for ArduIMU that includes support for MTK GPS module?

  • Hi, I'm using the MTEK GPS with Ardupilot 2.7.1 (with thermopiles - Shield V2). When I turn on the system after a couple of seconds the MTEK GPS shows the steady blue led informing that there is a GPS lock, but Ardupilot does not identify the lock and keeps blinking its blue led.
    If I reset ardupilot after the MTEK shows GPS lock (without taking out the battery), the ardupilot identifies the lock condition and shows the steady blue led working everything perfectly.
    Does anyone knows what can be going on? It seems that the startup process (cold mode) is not working properly for me.
    BYW, I'm using the baud rate as 115200 (I've setted everyting to this baud rate - GPS, xBee, Ardupilot init, etc).

    Thank you,
  • Hi, there are instructions in the manual for programming it via the FTDI cable (assuming you bought it together with the adapter). It should be pre-programmed but it may be that the firmware is old. Are you sure that you get a lock (LED on GPS adapter solid) in when NMEA mode is selected but not with binary mode? The mode shouldn't have any influence on the lock (from my understanding).
  • 3D Robotics
    The MTK library is supposed to send a command to switch it into binary and the right refresh rate.
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