Incompatible telemetry radio?

Navio / Edge Hardware
1

I bought what I thought was the same thing as a 3dr telemetry radio from a site based in China. Yesterday I was going to connect it only to find out that the connector is different.

The radio that connects to the drone only uses four wires instead of the 6 (the connector is wrong too, a big black connector instead of the small biege/whitish connectors).

Does this sound familiar to anyone? If all I need to do is find a different cable, then great! But I fear that I have to buy a completely different set of radios.

2

Could you post a link to the item?
Does it have USB connector?

3

I will try to find the link again I bought it from. I was trying to save money so went through a number of different Chinese sites.

I bought two radios, one with the USB (and a cable to so I can connect to to my phone) and one that goes to the drone. Let me see if I can dig up the link. If not I will take a picture when I get home.

4

Here is the exact link to what I bought. Looking at it now I would see that it has the wrong connection. But there is still only four wires where it looks like the Navio is expecting six. Do I need a different radio?

http://www.lightinthebox.com/915mhz-3dr-radio-telemetry-module-kit-for-fpv_p1275130.html?litb_from=sysmail#

Thanks,

Nathan

5

Here’s a couple of things you can do to be able to use this radio:

  1. If you have a DF-13 cable (for example from the Navio+ Wire Pack) you can make a correct cable using it and the one from the radio.
  2. Buy USB-to-UART converter (it should be like 4-5$) and attach it to the 4-pin cable. You can connect it to the USB port of Raspberry Pi.
6

Do you have any pictures or links for the correct df-13 cable I’d need? I have one from the Navio+ wire pack but it has the black female header pin heads on the other side.

does it not matter that it is only 4 wires?

7

The four pin connector on the Navio+ board is the IC2. Is that where I would send the telemetry over?

8

No, telemetry is not sent over I2C, telemetry is sent over UART. Here’s what you need:

  1. Take 6-pin cable from Navio+ Wire Pack and cut black jumper pins on it.
  2. Cut black 4-pin connector from the radio cable.
  3. Check the pinout of Navio+ UART connector (it’s on the bottom of the board) and the pinout of the radio. Connect cut wire ends as follows:
    GND - GND
    RX - TX
    TX - RX
    5V - 5V
  4. You can solder the joints just to be sure. Also, isolate joints from short circuiting each other using tape or heatsinks.
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9

Thanks so much! I will try that. I should have checked for information on UART before freaking about about the 6 pin connector I guess.

Thanks!

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10

You’re welcome, here’s how it should look in the end (wire colors may be different):

IMG_20150803_183555.jpg800×600 114 KB

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11

If you want to avoid a soldering take your 5 pin df13 cable, remove the connector on one end, now remove the extra lead. You should have a 5 pin df13 with 4 leads now.

Now remove the 4 pin df13 conn from the telemetry radio cable, and connect it to your custom cable.

Follow the pinout and you are good to go.

12

There are two types of df13 conn, white and brown/beige, the white conn do not fit well in the receptacles meant for the brown df13 conn. As you can see in last post the cable goes from white conn in the radio side to a brown conn on the navio side. This setup will not stress the df13 ports on the navio, while the white conn will stress the ports on the navio

13

thanks for all this info! I looked at my order and it looks like I did order the wire pack so I’ll go try to find the right wire and connect them together that way. I’m glad that I probably won’t have to go get new telemetry radios.

14

@aquila I think the white ones aren’t even DF13, they are probably ones of the Molex connectors that happened to be partially compatible.

1 Like
15

So I made the connection using my 6 connector DF13 I got in the wire pack. So now there are four wires going from the UART port to my radio, power, rx, tx, and ground. But there are two others listed on the Navio, IO18 and IO 17. Are these not needed?

16

I found that for UART you only need power, RX, TX, and Ground.

Now to figure out why I can’t get it to connect lol.

17

Possible options:

  1. Incorrect baudrate on telemetry port you use. I think these modems by default use 57600
  2. Wrong RX-TX wiring (there’s a lot of confusion between markings like RX\TX and RXD\TXD).
18

I thought I already responded to this thread with the results.

After testing it more and more, I gave up and ordered a different radio. It worked perfectly. Pretty cool.

I am thinking about switching out the connector the new radio shipped with though, it is slightly different than what the Navio+ is expecting, but still works. I just have to make sure it doesn’t fall out.