Replies to This Discussion

Permalink Reply by andy j on January 28, 2011 at 7:31am

As of this morning...

I now have authentication lists based on the units MAC addresses, and 128 bit AES encryption enabled.

an exclusive & secure connection that hops frequencies, and is spread spectrum - very nice indeed! that means it will be very tough to  sniff and interfere with your wireless control. It will also be more resilient to the environment around it

 

At the lowest power level (1mW), I was able to transmit from the far south basement corner to the far upper north corner of the 2nd floor. Pretty good i think - especially considering the duct work, walls, and floors separating the radios. I'm also using a crappy, made-in-china, throw-away, 1/4 wave-lenth antenna on both units. The baud is currently set to 115200 b/s.

 

 

 

Next on the list...

- construction of a semi-directional antenna

- reading back stats from the radio such as signal delay, and adjusting the power level accordingly

does anyone know of an efficient way to parse hex words? im newbie

Permalink Reply by Nima K on January 31, 2011 at 5:46pm

I use the DNT900 in the Andromeda UAV. You can see the one on the Autopilot and the other on the Ground Station. These radios are great. If you've got any questions I might be able to answer them as I've spent a bit of time programming these things.

Permalink Reply by andy j on January 31, 2011 at 7:28pm

Thanks for the offer! I just got them up and running. I do notice programing them can be flakey, and i get bad data transmissions that screw up some of the sentences sent. maybe one loss per 5 seconds?

 

Have you noticed any issues like that?

 

 

by the way, im a big fan of your build. Everything looks so clean, and your website is really nice with great pictures!

 

Permalink Reply by hamadivo on September 22, 2011 at 2:56pm

Hi,

i have a DNT900 but i can't establish the communication with it!

can you send me the shematic and sample code code used to configure it?

 

Thanks.

Permalink Reply by andy j on September 22, 2011 at 4:48pm

// byte VAR[] = {FB,LENGTH,TYPE,ARGUEMENTS}; // in hex

byte SET_BASE[] =  {0xFB,0x05,0x04,0x00,0x00,0x01,0x01}; // set as base

byte SET_RMOT[] =  {0xFB,0x05,0x04,0x00,0x00,0x01,0x00}; // set as remote

byte SAV_ONLY[] =  {0xFB,0x05,0x04,0xFF,0xFF,0x01,0x01}; // save

byte SAV_RSET[] =  {0xFB,0x05,0x04,0xFF,0xFF,0x01,0x02}; // save and reset

 

All the configuration information is in the PDF user manual - but these 4 should get you started!

 

make sure to read the PDF on the connections for the DNT900 board. And level-convert the 3.3v logic to 5 volt for things like 5volt arduino!

 

sorry, i don't have a schematic at this point. at least nothing on computer - and im away from home

 

 

 

BEST of luck! let me know if there's anything else i can do!

Permalink Reply by hamadivo on September 23, 2011 at 10:50am

Thank you.

i read tha datasheet but can't understand how i connect some pin (like CFG, DTR ....).

i want just use RX and TX  to send data.... (i converted 5V to 3.3V like datasheet)

can you send me the pinout connection ?

 

Thanks.

Permalink Reply by andy j on September 23, 2011 at 12:39pm

it explains the purpose of the input pins, and their accepted input states. The CFG is only low when you want to configure the dnt900. else, high allows transparent communication

 

Focus on pins 18,19,20,21,24,30,31,32

 

pins 25 and 26 are great for LED status lights

Permalink Reply by hamadivo on September 23, 2011 at 4:39pm

Hello,

i found the error (ouuufff), i don't connect the pin 30 to the ground.

 

Thank you for your help.

Permalink Reply by andy j on September 23, 2011 at 4:44pm

NICE glad it works! i think its better to tie it to an I/O so you can do flow control. haven't done it yet myself, though!

 

glad it works!

Permalink Reply by bGatti on January 28, 2011 at 8:06am

This is quite cool.

 

Permalink Reply by andy j on January 28, 2011 at 9:21am

I am contemplating building up a development kit on PCB for sale here that would integrate this radio into a little micro controller board that would configure and maintain this radio. It would also give general I/O's and controls that you could effectively build your own custom radio-control system.

Permalink Reply by Jonathan Lussier on January 28, 2011 at 9:58am

Best would be to make a board is size-compatible with the APM and plugs into the PPM inputs... plug N play!

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