How to setup Pixhawk + DroTek NEO-M8N / HMC5983 Compass?

[Vaako]

Hello,

I like to connect the DroTek NEO-M8N with the HMC5983 Compass to a Pixhawk (clone).

Here are my questions:

Why are there solder pads on the PCB to choose between 3.3v or 5 volts, is this related to the TTL Level voltage or for supplying the correct voltage to the GPS + Manetometer chip(s)?
However the pixhawk provide 5 volt out on the gps connector.

I also like to now the main importent settings in U-Center to make the ublox communicate correctly with the pixhawk, for example the baud rate must be 38400 and protocol UBX but I need the other parameters also.

Or is there a u-center GNSS configuration file available for download?

Thanks in advance for the help!

[LoriuQ]

Hi Vaako

The solder pad on board is used to define your input/output signals voltage. (TX RX)
To work with Pixhawk, the 3.3V solder must be enabled.
The HMC component is the same as on pixhawk.
Normally, it’s not necessary to configure the Drotek GPS default baud rate (9600).

Have I answered your questions?

[Vaako]

Well I have done some parameter changes with U-Center and now it does not receive any sats anymore.

I’m gone ask DroTek if they can readout an NEO-M8H and send me the GNSS file this way I can flash that file and the GPS would be back in default mode.

About the default baudrate 9600, I believe Pixhawk wil only accept 38400 baud.

Any help or suggestions are welcome.

[jerome]

I will send you the file on monday.
My GPS is configured on 9600 BAUD and the Dropix will configure the GPS at each boot.
It will put the BAUDRATE on 38400.

[Vaako]

Thank you very much !!!

I also like to now what is the Front side of the GPS since I dont now wich direction it’s heading to?

An arrow on the PCB could make that easyer to mark the front side.

[jerome]

You can find the front of GPS on our guide about the Dropix.
We can’t put a arrow on the PCB because our GPS is used on several projects like Arducopter, Openpilot, Multiwii or Arduino board.

[Vaako]

Thanks for the info!

I have attach a picture for other people who like to now.

[Vaako]

Today I send back my GPS+Compass module to DroTek for testing/repair or exchange for a new one (depend on their service).
At the moment I try to change settings and write them CFG (save current configuration) it does not work at all anymore.

For Pixhawk I need to change to these settings:

1. NAV5 = Airborne or Pedestrian < best for hovering.
2. PRT = Protocol out (UBX) + 38400 Baud rate.
3. RATE = 200 ms] tot have 5Hz refresh rate.
4. SBAS = for European users sellect EGNOS.
5. CFG Save current configuration / Devices 0-BBR + 1-Flash

The default settings are 9600 baud and ubx+nmea protocol, only then I can receive some sats.
With U-Center I see very bad quality of reception, the signal is not constant look at the screenshot:

[Vaako]

After I received a GPS replacement from DroTek it works rock sollid after testing

Here you can see a picture of the reception with only 180° degree of the sky (hemisphere) visible.

[thomasmueller]

Hello,

I have several question to this:

1. since the module does not come with USB connection, i need a seperate FTDI programming adapter to connect to PC?

2. Second, how would I wire the Neo M8n with the Pixhawk? i read somewhere the wires for the HMC5983 go into the I2C and the M8N wires into the GPS plug of the pixhawk?

Thank you

[jerome]

1. since the module does not come with USB connection, i need a seperate FTDI programming adapter to connect to PC?
   -> yes

2. Second, how would I wire the Neo M8n with the Pixhawk? i read somewhere the wires for the HMC5983 go into the I2C and the M8N wires into the GPS plug of the pixhawk?
   -> yes

[thomasmueller]

Thank you very much for the quick response.

I have ordered the Neo M8N from you.

Do you think i need to make settings at all with the FTDI or can i go ahead and just connect it to the pixhawk without making additional settings to the GPS?

thank you,

Thomas

[jerome]

No need to configure the GPS with the Pixhawk!

[Vaako]

The neo-m8n is configurated as 9600 baud and when the pixhawk boots up it send an initialization string to the neo-m8n so that it change it’s baud to 38400 and othere desired parameters.

Only if you want to do some some fine tunings you need an usb-to-rs232 interface.

For me I like to set the NAV5 “Navigation mode” to Pedestrian instead of Airborne because Pedestrian has better results on hovering.

Than there is also RATE and SBAS you can change.
Rate can be set as you like but in my opinion 500ms [2Hz] is the best at the 38400baud.

SBAS you can set this to** EGNOS for EUROPE** and WAAS for USA (other regions I don’t now you have to look up).

[Japamar]

Hi everybody…

I have this fantastic GPS module from DROTEK andit works just great.
I have done some setting changes with U-Center (Rates: 10Hz, Port 38400…)
But i have some questions.
Is it possible to receive more than 2 GNSS systems simultaneously? Because i can see 3 QZSS satelites but no signal (See picture, Red arrows).
What type of antenna this module has. Active or passive?

Thanks.

[jerome]

Are you sure to need QZSS sat? Look at this
en.wikipedia.org/wiki/Quasi-Zeni … ite_System
Where do you live?

[Japamar]

Thank you for you quick answer…

You are right, now i think i dont need QZSS sat because i live in Portugal.

But, is it possible to receive more than 2 GNSS systems simultaneously?

And the second question was: What type of antenna this module has. Active or Passive?

Thank you.

[jerome]

But, is it possible to receive more than 2 GNSS systems simultaneously?
-> yes it’s possible

And the second question was: What type of antenna this module has. Active or Passive?
-> passive but there is a front end (amplifier + filter)component on the GPS

[Japamar]

*But, is it possible to receive more than 2 GNSS systems simultaneously?
-> yes it’s possible
*
what do I need to do to make it possible? Is there any settings I must change or some configuration file?

Could you please tell me how?

Thank you.

[jerome]

No need to configure the GPS!
Very strange you receive only 2 sats.