MT3339 GPS bricked since update

[mac.rcnet.com]

Hi all,

I have try to update my MT3339 GPS break out board (http://www.drotek.fr/shop/fr/90-gps-pa6c-llc.html) with the 115200 FW found on a russian website since i've seen somebody here have done that and have a MT3339 10HZ and 115200 working fine -> http://forum.rcdesign.ru/f123/thread221574-135.html

The issue is since that update, i'm not able to communicate with the GPS using my FTDI (http://www.drotek.fr/shop/fr/65-multiwii-ftdi-arduino-serial-usb.html)
The minigps tool can't connect to the GPS and the MT3339 PC Tool connect to the GPS but all bauds rate i chose, including 115200 return no information except some spécial characters like ???KKK?????///:::;..N???

Is someone have an idea what could i do ? i'ma afraid the gps is bricked

thanks in advance

mac

[gompf-2]

Hi,

I used this file and it´s OK. I hope you thought about 5V/3.3V voltage level and set the solder jumper on your FTI to 3,3V for direct connection to the GPS, otherwise I´m quite sure it´s dead now. It happened to me once also, but I was lucky enough to use the aux USB ports of an IBM keyboard which was either just to weak to deliver the short current or instantly disabled the port/cut the power. After the next PC restart everything was fine again and I went to bed .

Regards,
gompf

[mac.rcnet.com]

Hi,

thanks for help, my FTDI is working at 5v but the GPS break out is 3.3V/5V.
Before this update the GPS worked fine with this FTDI and in 5V under minigps tool, i really have a problem since i've done the update.

[gompf-2]

OK,

sorry I only checked half of the scene... Is it still possible to connect to the flash tool?

[mac.rcnet.com]

no problem,
flash tool connect seems to work and don't return any error in every baud rate setting and when i run the flash, i have the "BROM_CMD_START_FAIL" error.
yesterday i have put the ftdi in 3.3 to test, the issue is the same.

[gompf-2]

OK, not possible to call the bootloader. IIRC I read something like this while searching the web for the firmware, the solution was to power up the GPS at a defined time so the bootloader calls itself. Can`t find the post any more...
I just proofed that "connect" in Powerflash only connects the flashtool to the comport, there is no communication to the module at this state, works with a blank fti only. Try to seperate the power connection to the GPS, connect FTI to GPS TX-RX-GND, "connect" with powerflash and try to power up the GPS module in the moment/very short after you press "download". I would try it quite often, as it maybe hard to get the right moment.
As I wrote I can´t proof this works as I can´t find the info anymore, but if the bootloader is triggered during power up there is a chance.
I coud check what comes from the GPS modules TX-RX pins during power up, but not this evening.

Are you sure you´ve choosen the correct module/download agent? Maybe it overwrites part of the bootloadersection when something is wrong here.

[mac.rcnet.com]

thanks a lot for your very great help, i will try to flash again, my issue is that i can't find other firmware
the software used to flash is the good version (1.22) updated to support the MT3339, the firmware is announced to be the 10hz 115200 bauds for MT3339, assuming it's right, i have the good firmware (i hope)

[mac.rcnet.com]

I've tried your tricks without success, i really think the gps is "dead" now, it work but i can't communicate anymore with it.

[weisseruebe]

Hi, I've exactly the same problem. I updated a Pa6C from drotek with the 115200 Firmware. FlashTool said success, LED blinks, but I only get rubbish from the serial port at all baudrates from 4800 to 115200.
Looks like the module is set to a baudrate I can't configure or something like that.
I tried uploading the firmware right after power cycling very often without success.
Any ideas? Could you solve it?

[weisseruebe]

Alive again

I set the update baudrate to 9600bps, prepared everything, clicked "Download" and powered on the GPS shortly AFTER clicking. That did the trick. Upload worked fine and it is alive again!