GPS (GP-02) kit module fitted in a GD-77

[bg5bdt]

Daniel

Can post a link to the module and the antenna

I know the antenna is https://www.aliexpress.com/item/1005004473774121.html

But I'm not sure of the exact GP-02 board you bought.

What glue did you use for the GPS module ? Some sort of epoxy?

Good afternoon. Do you have a schematic for installing GPS

[BH1JSS]

Hi,

Here is a small hack I made on one of my GD-77.
I fitted a GP-02 tiny GPS module and a 8x8 active GPS antenna.

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Some screengrabs:
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Cheers.
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Daniel

"Hello friend, I installed the GPS module following your tutorial. I used the BZ121, which operates at 3.3V and has a baud rate of 115200. However, it seems not to work on the MD760. Could this be related to the baud rate?"

121.jpg (64.36 KiB) Viewed 3014 times

[F1RMB]

Probably, the firmware expect 9600bds.

EDIT: just checked, it seems to be a 5V device, you should check if it works at 3.3V.
Also, its protocol is NMEA and UBLOX (binary), you also need what it's spitting on the serial, as the firmware only handles NMEA-0183 sentences.

Cheers.
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Daniel

[BH1JSS]

Probably, the firmware expect 9600bds.

EDIT: just checked, it seems to be a 5V device, you should check if it works at 3.3V.
Also, its protocol is NMEA and UBLOX (binary), you also need what it's spitting on the serial, as the firmware only handles NMEA-0183 sentences.

Cheers.
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Daniel

Thanks! I saw through the serial port tool that it can work at 3.3V and output U-blox protocol data. I can't find the official configuration tool to change the baud rate. I'll try u-center again.

[LY1RF]

How radio know that GPS module is installed ? Without module in GPS menu you cant turn gps power to on and if it is powered off how radio can know that its there ? Or in any case radio is trying to power on module and listen for nmea messages and changes menu to on if messages is heard ?

[G4EML]

You are correct. At power on the GPS is enabled and the firmware looks for valid NMEA data for a short time. If no data is seen then the GPS is set to not fitted.

There is no way for the firmware to talk to the GPS so you would need to configure it to NMEA 9600 baud before fitting it and the changes would need to be permanent.

[LY1RF]

@f1rmb I see you've tried to use N/F pin of gp-02 module, but ended with mosfet for vcc. Can i ask why ?

[F1RMB]

No, I tried the NF pin on the bench to check the power consumption, if it was in the specs.
But, to save battery power, it was better to completly cut the power to save few mA/h. And the MCU can't deliver enough current to power the module + the antenna.

[LY1RF]

I'm thinking to use mp62055 https://www.monolithicpower.com/en/mp62055.html

btw i've installed sl871-s gps module in dm1801 , will post photos later

[W7OBB]

Anyone else tried this? Very interested in adding gps to my 77 but don’t want to screw it up.

Like the idea of a less invasive mod if one exists.