Wireless telemetry

[lukasz]

Just this week i found this page and I'm very interested in the project.
I have already contacted Tom and asked him to put my name for the next tier of Gluonpilot module.

Is there a plan to extend Gluonpilot with some kind of wireless telemetry?
Something similar as in the ArduPilot project (http://docs.google.com/View?id=ddjmqgw3_43gm6gvggf)
Guys from that project used Xbee modules to provide witless communication between UAV and ground station.

Can the hardware in current state be extended by adding such module?

[Tom]

Hi Lukasz,

Yes, I already have a module which combines a switched 5V power supply with an XBee-pro modem. It is connected to the uart output.
Once I have more time to finilize the design, I will have some PCB's made!
I have no idea about the price, but a while ago there was a special auction where Digi sold the XBee-Pro development kit for only 99$!

P2260172 [640x480].JPG (95.66 KiB) Viewed 24664 times

Tom

[Mitch]

I've been using xbees for a while with good results. I've even used them during development so there aren't any wires connected to the module when I want to move it around. Sparkfun has two different boards that are very reasonably priced. One is usb and already has an ftdi and voltage regulator on board. It can directly connect to a pc or laptop and can be usb powered. The other is ttl rs232 and has a voltage regulator on board. It will connect directly to the gluonpilot board with four wires and a connector.

[asifjahmed]

I have found adafruit's boards to be very nice, too - has an onboard regulator to power the pro modules and connects right up to an FTDI cable:

http://www.adafruit.com/index.php?main_ ... cts_id=126

-Jamie

[lukasz]

Nice
So the adafruit's board could be connected directly to FTDI pins on Gluonpilot board.

Regarding the telemetry...is this just one way communication?
Is there a possibility to have any communication from XBee to Gluonpilot?
Will I be able to send data through FTDI to Gluonpilot board?

I'm asking because i see that this is an output channel.

[Mitch]

The adafruit and sparkfun boards are convenient interfaces for connecting to the xbee modules. There are several flavors of xbee. In general, they create the equivalent of a wireless two way rs232 serial connection.

Tom has provided the "FTDI" connection which is really uart1 on the dspic. This interface is 3.3 volt ttl level rs232 with a power pin at 5 volts. The "GPS" connection is the dspic uart2. It is 3.3 volt ttl level rs232 with a power pin at 3.3v.

The "FTDI" designates a conversion between ttl rs232 and USB and implies use for hardwire interfacing to a laptop or pc via usb on the ground.

For inflight telemetry, the usb/ftdi is not necessary on board because it is a simple rs232 interface between the pic and the xbee. The caveat is the xbee is 3.3 volts and the uart1 connection is powered at 5volts. Thus voltage regulation is necessary for the onboard xbee. An FTDI can be used here for the ground station to adapt the ground station xbee to the pc (or laptop).

Thus, a pair of xbees and two interface boards, one serial and one ftdi (or both serial) cover all of the permutations.

Hopefully I'm not confusing the issue - serial connections from a pc (or laptop) directly to the xbee or to uart1 are possible without the ftdi, however, the pc (or laptop) com port logic level is +-9 volts and voltage conversion is necessary ie 3.3v ttl to +-9v rs232.

[veinblz]

Hi this sounds very intersting, do you guys know if a ZIgBee dongle can connect to the Xbee pro module?

I'm not too sure what to make of the datasheet at http://www.adaptivem2m.com/zigbee-technology/zigbee-usb-dongle.htm

Let me know your feedback...

Jon

[Mitch]

Nor can I say for sure - but it looks like it can do 802.15.4 stack and is probably compatible with the xbee pro 2.4ghz modules. It may not be a good idea for anyone who is planning to eventually use 2.4ghz rc link.

Here is another xbee adapter source http://www.newmicros.com

[lukasz]

I'm just looking at xbee modules.

I was thinking to buy two 6mile range xbe modules (http://www.sparkfun.com/commerce/produc ... ts_id=9097), but since I don't have experience with those kind of wireless modules I wanted to know if having such xbee module together with an FM receiver (35mhz) wont cause any disturbances.

I know that my RC transmitter (Hitec7) together with Jeti 5 MPD receiver have about 1km range, but I would like to do some out of range flying .

Did anyone try such solution?

[Tom]

Hi Lukasz,

In Europe you need the 868MHz version instead of the 900MHz one. They are not so easy to find. Lipoly sells the development kit: http://www.lipoly.de/index.php?main_pag ... c8vofpqjl4

If you place the modem and the rc-receiver too close they will interfere. I had to make sure the distance was at least 25cm (not easy in a funjet ) and limit the power to 20mW. An option would be to install the module with RPSMA connecter and move the antenna (instead of the whole module) far away from the rc-receiver.