Replies to This Discussion

3D RoboticsPermalink Reply by Chris Anderson on August 5, 2012 at 8:57am

Maybe you've got your RX and TX wires reversed? (RX on one board should go to TX on the other, if memory serves). I'm not familiar with that particular USB-to-serial board. 

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Permalink Reply by Boston UAV on August 5, 2012 at 9:59am

Success!

(Although I had to wire Rx to Rx and Tx to Tx.)

Time for coffee..

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Permalink Reply by mP1 on January 25, 2013 at 4:26am

Im confused what exactly your comment means. I have some 3dradios from udrones and one of them (the "air') is stuck w/ a solid green LED. I am have tried connecting it sing the supplied USB cable and the green remains solid and any attempt using the config tool to do anything fails with a "Fail to enter command mode" error.

Any tips are appreciated.

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Permalink Reply by Bill Bonney on January 25, 2013 at 7:27am

Are you trying to reprogram your radio?

The solution here comes from the most common problem with serial comms. Does TX go to TX or RX on the connect to device, and the answer is that "it depends". If you have a master (DTE) connecting to a slave (DCE). TX goes to TX and RX goes to RX, if are connecting Master to Master you need to swap RX and TX.

http://code.google.com/p/ardupilot-mega/wiki/3DRadio for more info

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Permalink Reply by mP1 on January 25, 2013 at 4:51pm

Im just trying to get the two radios to connect. I thought perhaps the air radio might need a firmware flash,but first i wanted to verify that it responded to commands. The strange thing is its Green LED is always solid even when the other radio is disconnected/off.

Pardon my ignorance but i have no idea which radio should the master and which the slave. Looking at the cabling neither of them have any crossed wires. The wires are standard without any crosses.

I bought the kit so im assuming everything should be correct. If not which should the master and which the slave ? What does a typical kit look like, ground=master and air=slave. Looking at the pics above, i notice there are a few crossed wires, im assuming that is done to swap the TX and RX. My cabling came without any crossing and i have not attempted to change this. See attached pic.

<both-radios-N-cables.JPG>

The strange thing is the "air" radio when connected to via USB seems to see AT commands, as the red LED flashing to match at the right time. The problem is it just does not respond at all. The 3DRConfig utility complains w/ a "Fail to enter comand mode" as described above.

Should i short the CTS and GND and try and enter bootloader mode and send a new firmware ?

Attachments:

• both-radios-N-cables.JPG, 1.1 MB

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Permalink Reply by Bill Bonney on January 26, 2013 at 9:10am

The way you have it set up should 'just work'. That's my experience. You can try and reflash the dead radio. That may work if the FW has been corrupted. FYI: There is no difference between the 'air radio' and the 'ground radio' just there location ;-)

And my original post was in response to the solution that Boston UAV had found to reprogram his radio. When I was talking about master & slave I was talking about the serial interfaces, i.e the one on the computer that connects to the serial interface on the radio.

In your case you should be able to reflash with the FTDI cable you have without swapping wires. Boston UAV was using a similar but different adapter.

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Permalink Reply by mP1 on January 26, 2013 at 7:19pm

Thanks Bill, shorting the CTS and GND, then let me upload the latest firmware. After that the Green LEDs on both radios show they are connected so thats sweet.

As a ref im putting a link below for others.

http://code.google.com/p/arducopter/wiki/3DRadio

jump to 

Forcing bootloader mode

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Permalink Reply by Satetha Siyang on March 20, 2013 at 6:59pm

I must thank you very much. I have a same problem and try to solve it but it feel not work. 

Your suggestions helped me a lot. 

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Permalink Reply by mP1 on March 21, 2013 at 2:52am

What have you tried to do ? Have you tried any of the things that Bill or myself suggested ?

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Permalink Reply by Satetha Siyang on March 21, 2013 at 2:58am

I do follow Chris Anderson suggested. 

"Maybe you've got your RX and TX wires reversed? (RX on one board should go to TX on the other, if memory serves). I'm not familiar with that particular USB-to-serial board."

it work for me. 

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Permalink Reply by Kabir on January 25, 2013 at 7:34am

Does that USB-TTL use a SiLabs chip?

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Permalink Reply by Boston UAV on January 26, 2013 at 7:39pm

Silicon Labs CP210x USB to UART Bridge

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