3dr and Ethernet to RS232 Serial port

Hi out there.
Anyone know how to connect a 3dr unit to an Ethernet to RS232 Serial port card.
I am wanting to take the 3dr data and move it via my wifi to my Windows Tablet running Mission Planner.
I know I can have a USB device plugged into it, but I would rather it get put out over my wifi. I also have an IP to video server on my ground station and this allows me to stream FPV video to my tablet, I now want to get the telemetry to the tablet as well, but I am not sure how to make the connections and I don’t seem to be able to find the documentation. Any help would be appreciated

You will need a level-shifter as RS232 is +/-12V and the 3DR radios have a TTL serial port which is +5/0V.
This should help.

Thank you for the fast response. Its greatly appreciated.
I hate to say it however your link has created more questions.
When I look at a device like the link below which was described else where as a method to connect a 3dr to Ethernet (only that it could be done). It;s documentation indicate that its operating voltage is either 3.3 or 5 vdc. The pin out an din for the 3dr and the serial to ethernet devices look nearly identical.

ebay.com/itm/120919305975?ss … 1438.l2649

The pin out for the 3dr air module is

Serial to Ethernet Pin out is
vDD (4.5~5.5v)
VCC (3.3v)
RST (Reset)
TXD (UART Transmission Pin)
RXD (UART Recieve Pin)
CFG (Config Pin)

How I envision they would connect
3dr Air Module conect to Serial to Ethernet

3dr card Serial-Ethernet
CTS Not Sure
RTS Not Sure

So when I read this information I struggle with understanding the need for Level shift device.
but then again, I have no clue what I am talking about so I could be wrong.

Your ebay item doesn’t look like an RS232 to ethernet converter. It looks like an ethernet module with TTL serial port.
The difference is that the ethernet module is for connection to a microprocessor and will usually need initialization commands e.g. for IP address and starting to listen at a certain port. You wouldn’t need a level shifter for that but you would probably need a microprocessor to control it - in the easiest case, an Arduino. They also usually don’t remember their configuration after power off.

RS232 to ethernet converters are also called serial terminal servers and are for connecting serial devices to a network. They are usually configured via a web interface and remember this configuration after power cycling. Typical usage for those would e.g. be inband remote access to a serial console port of a router in a data center.

The problem with those ebay items is that you never really know what you get. Maybe it is a terminal server, maybe the seller has no clue what he is selling and just copy-pasted the description from some item that looks similar.

Besides, if you anyways want to go via WiFi, you could check for a WiFi to serial module e.g. Roving Networks WiFly or something similar. There’s also WiFi-modules in X-Bee form factor which fit the 3DR X-Bee Explorer boards.

Thanks that makes sense.
This link is the the article that got me started down this path
github.com/arthurbenemann/droid … to-connect
What I want to do is take the data from a 3dr receiver and move it out over the Ethernet and subsequently the wifi so my windows tablet can make use of it.
It sounds reasonably easy, this article hints that I just need that ebay device and the world is good.
I will look at the device you pointed out.

Also wanted to use a wifi router because I was streaming video as well.

I use this wifi to serial converter and it works very good

no.mouser.com/new/rovingnetworks … orksRN174/

Thats very cool and looks like it would do the trick but what I really want is to simply convert to an IP ethernet stream that I can push through my router. This way I can combine streaming video and data.
Then my tablet has access to everything.
Not that I am planning on flying it that way, but it would be handy.
Right now I don’t know a way to connect to more then one wifi at a time so just moving it to an eithernet ip stream is the best solution. However if I can’t figure it out. this would be the answer for the data part is its far more important then video.

thanks for getting back to me

Have a look at this module sparkfun.com/products/10822 it maybe what you need?

thanks but no that’s a WIFI device.
Whats interesting is that each time someone steers me to on of these devices and I read the description. It more and more aligns with the description of this devices interface.
tcp232.net/Serial-To-Etherne … odule.html
I may just go buy one and another 3dr air module and plug um together and see what happens.
Worst case is something goes poof in which can I am not out a kings ransom for it.

“I know I can have a USB device plugged into it, but I would rather it get put out over my wifi”

This is why we suggest a wifi device :slight_smile:

Thanks, you right that the wifi device is a great solution. But I want to stream video and Mavlink data to my milspec tablet. Thats why I am looking to use a serial to Ethernet adapter. I want to have my base station take the various inputs and stream them, thus the inquiry.

I have a video to IP server which I have plugged into a test wifi router, just need to add the Mavlink data and i have a total package. Well not completely, I would love a simplified Mission planner interface that would allow programming via my tablet in an easier way. But thats really not a concern.
Jut want that base station wifi solution.

But thank you. Its a great hobby and a great community.

If you check out this video you can see the tablet I have, with the exception that mine is a slightly older model. But you can see in the vid that he has control of the drone from the tablet.
I am wanting to replicate that level of control for my hexacopter.


Hey ricky, did you ever get this figured out? I plan to run the same kind of set up. (Video server with wifi router) I plan to have my antenna stand untethered to my ground station and the only thing holding me back is the ability to connect to the 3DR radios via ethernet through the router.

With how cheap the 3DR radios are, especially the clones, I wouldn’t mind giving something a try, I just don’t know what to order yet.

For the time being, I went ahead and ordered the serial to ethernet converter (same as the link you posted)

From the user manual I read about this device online, I believe it will work.
Will take about a month for it to arrive since it has to ship from China, but I’ll let you know if it works!

I really hope they come out with that ethernetGCS board! It looks really nice! I even saw them talking about adding antenna tracking capabilities (servo pan/tilt outputs)!


I would be interested in hearing your progress. Please post how your making out. As for EthernetGCS as I understand it is no longer being developed which is a shame, but perhaps this will solve the need.

We shall see…good luck and thanks for letting me know.

Just a few more days and I should have the serial to ethernet converter in my hands. It takes a while when coming from China…

hope its not coming from Goodluckbuy.com.
Three months now and I am still waiting.

Ordered mine from ebay for around $19. Tracking number says it’s in New York, so shouldn’t be too much longer.


excited to hear how you make out.