Servers by jDrones

PixHawk3 and echosounder with NMEA output

(rmackay9) #21

It looks like the baud rate should be 4800 or maybe 9600 but I’m not sure.

I think our NMEA range finder driver should be able to consume either format 2 (DBT) or format 3 (DPT) messages.

If you have a dataflash log I could have a peek to be sure that the data is or isn’t coming in and that you have your parameters set correctly (as far as I can tell)…

(Scott Macklyn) #22

Bad news, the Pixhawk has no dataflash log. I can only get the tlog from the PC via MP.
Not sure why the unit doesn’t have one.

Not sure if this affects it, but I didn’t have the GPS plugged in? I’m using the Here+ with the RTK base for input.
If it is meant to store a file with Lat/Long and the Depth, no GPS connected it wouldn’t be able to store it?

(Scott Macklyn) #23

Hi @rmackay9, I have had a win!

I went and rewired the whole setup I have from the sounder to the Pixhawk. Installed some new quick connects, etc. I followed the wiring setup as specified in the ArduRover documentation.

Doing it this way I got no data in MP. I switched the TX and RX between the RS232 to TTL Converter and the Pixhawk. I then got data in MP but only when I connected to the unit via Bluetooth to the PC. Stop the Bluetooth and then no data.

So I switched the TX and RX wires from the Unit to the RS232 to TTL Converter and Viola!
So I am unsure if the Converter I got already does the switching internally? But I am getting the data through MP via RS232 and correct values.

I can’t wait to install this into the Boat and get the RTK Logging with the Depth. This saves me about 1-2kg of Weight that I don’t need anymore.

Great job with the NMEA Driver. If you like I can draw up a wiring diagram of my setup so you could add this onto the list of supported depth sonars/sounders?

Thanks, Scott. (P.S. Donation coming to ArduPilot in the coming days for the Software in the Public Interest, Inc.)

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(rmackay9) #24


Great that it’s working!

Yes, if you’ve got a connection diagram (and links to parts if possible) then I’ll add it to the wiki. Great!

(Pau G.) #25

Hi all,

I’m trying to connect a Lowrance Totalscan and Elite 5Ti to Pixhawk but I have some doubts.

  • The NMEA 0183 output from Elite is an analog or digital signal?

  • Can I wire it with a Sparkfun RS232-to-Serial converter to the Pixhawk’s TELEM port as Randy did with ECT400?

All your comments will be very appreciated.

(rmackay9) #26


I’m not toot familiar with the Lowrance Totalscan but a NMEA 0183 output is certainly a digital signal. In particular it’s a serial protocol (i.e. a string of characters). I think the RS232-to-serial converter used for the ECT400 should work.

If you’re looking to use the Elite 5Ti as well then that probably means that the output from the Lowrance Totalscan needs to be split and sent to both the flight controller and the Elite 5Ti. The diagrams for the ECT400 setup show both the transmit and receive pins are connected but in fact, it should work with just the transmit output (from the Lowrance Totalscan) split and sent to both the flight controller and the Elite 5Ti.

The thing to be careful of is the voltage of the pins connected to the flight controller’s telemetry (aka serial) port. The flight controller can only handle voltages up to 5V so if you check the voltage across the ground and transmit or receive pins and find it’s over 5v then that’s dangerous to connect.

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(Pau G.) #27

Hi Randy,

After some trials, this is my situation:

  • Totalscan connected to Elite 5Ti with the standar cable
  • Nmea/power cable output from Elite 5Ti to RS232-to-TTL converter.
  • RS232-to-TTL converter to TELEM2 Pixhawk

As you can see on picture, from nmea cable I have 5 cables (TX_A, TX_B, RX_A, RX_B and ground) It seems a RS422 output not RS232. But there’s an alternative wiring for RS232.

My wiring scheme is:

Yellow (TX) from ELITE to RX at DB9 converter
Orange (RX) from ELITE to TX at DB9 converter
Shield (ground) from ELITE to GND at converter

From converter to TELEM2 I’ve followed your diagram.

On ELITE config I only define DPT nmea sentence as output
RS232-to-TTL is like this one: (MAX3232 chipset)

The MP parameters setup as


  • No Sonarrange data
  • 8-9 Volts on converter input
  • 4-5 Volts on converter output

Inverting RX and TX does the same.

Any idea? :sweat:

Thanks so much

1 Like
Mapping a lake with ArduPilot
(Andrei) #28

No need in converters just add a resitor.
Yellow (TX+) from ELITE to telem ground
Orange (RX+) from ELITE to telemetry +5v
Blue(Tx-) from ELITE to telemetry rx
Green(Rx-) from Elite to telemetry tx
And you need to join Blue(Tx-) from ELITE and Yellow (TX+) by 100 Om resistor. Niko77_lowrance_NMEA_pinout

1 Like
(Pau G.) #29

Hi Andrei,
Thanks for your comments.
I’ve tried your scheme but it doesn’t work for me. No sonarrange or sonarvoltage data.
Maybe any detail I’ve missed?

(Olav Aamaas) #30

Sure that all settings and all wiring is correct? The things I did not get right from the start was:

  1. Setting RNGFND_ORIENT = 25 (down), ref wiki page
  2. The transducer to be put in a water tank/bucket (to provide readings output)
  3. Serial input wiring mismatch (tx/rx) and common ground
(Pau G.) #31

Hi Olav,

Thanks for your comments.
I’ve tried all this and other situations but no success.
I will inform if I finally reach anything.
It colud be nice to connect a commercial fishing sonar to pixhawk for most people.

(Abhijeet Gheer) #32


I would like to know if there is any way to output these NMEA sentences given to Pixhawk 2 by Emlid Reach M+ to a Ground Penetrating Radar (GPR) which has a RS232 connector?

If so, would you be kind enough to detail how it can be done? (which port can i configure and what parameters/commands will i have to use/change?)

Thank you!

(Peter Hall) #33

it not in master yet

(Abhijeet Gheer) #34

Im an absolute beginner to this… how do i write this code into PX2 and how do i configure any specific port to output NMEA?

(Peter Hall) #35

wait till it gets reviewed and makes it in, defiantly not recommended for absolute beginners to fly development code

(Abhijeet Gheer) #36

Now that it is merged into master, can you guide me as to how to move forward and incorporate this so that i have the functionality?

(mendrink) #37

I follow this setup with echologger EU400 (with FTDI USB connector). I have bad LIDAR health in MP. And there is no sonarrange data. I already setup NMEA output to DPT. I try to switch Rx/Tx from echologger to pixhawk but no success.

Do i need USB to TTL converter? how to remove bad LIDAR health?
MP version 1.3.68, Ardurover V3.5.1