Telemetry: schemes and details on succeded connections

[afernan]

UPDATE: 17 Jan 2013. The new GCS let now connect directly the 3DR USB to the tablet, this thread become obsolete. See this post:

This is a list of succeded connections in addition to the wiki page:
http://autoquad.org/wiki/wiki/autoquad- ... etry-xbee/

There are four combinations tested:
XBee, 3DR over ground control on WINDOWS or ANDROID (N7)

I´ve succeded all but 3DR+N7 (a piti, the one more interesant for me)

1.- XBEE on qgc (Windows): SUCCEEDED
Program XBee modules (Tx & Rx to baud = 115.200)
in QGC: Baud = 115200, Flow Control OFF

2.- XBEE on ANDROID thru Bluetooth : SUCCEEDED
Tx side is the same than used for windows (see previous image)
Rx connections are the following (separated power supply needed 5V)

XBee on ANDROID.jpg (133.5 KiB) Viewed 20078 times

3.- 3DR on WINDOWS qgc (SUCCEED)

3DR on Windows.jpg (100.83 KiB) Viewed 20076 times

4.- 3DR on ANDROID thru BT (NOT SUCCEED)
Used same Tx configuration (described in point 3)
BT module connect to N7 but AQ doesn´t get connected.

I hpe this help you folks. I´ve been crazy several days (still not finished). Wiki could be updated with more details like this.

Angel

[kinderkram]

Thx for your detailed description, Angel!
Where did you get your 3DR from?
Concerning your connection #4: did you connect the BT module also Rx<->Rx? If yes, please try to swap Rx & Tx.

[afernan]

3DR got from 3DR store:
https://store.diydrones.com/

About the connection AQ+3DR+Android (not succesfull) I´ve tried all (as you can image). In fact, the Nexus7 connects to BT but is not able to connect to AQ. Maybe some inside the configuration of the 3DR itself. I´ll continue investigating.
I´m still wayting to hear someone that success on that (if any).

I´ve been using long time XBee and 3DR on other systems and it´s really much better 3DR (something like x5 times distance range)

Angel

[kinderkram]

Hmmm...
It has to be something between the BT and 3DR then.
Please post a screenshot of your 3DR settings (including "advanced settings")

DIYD advises their users to disable ECC and use Op resend on the local device only. I'd play with these settings.
Does the 3DR in any way when you try to send data?

[monkey1]

My 3DR also didnt push up to 115200, push it up then both module lost connection with each other. Return to 57600 is fine.

[afernan]

@Kinderkram
I´ve tested with your recomendations without succes:
disable ECC
use Op resend on the local device only

It works always on QGC in windows with any of these configurations.

This is my conf:

[chschmid]

I see that you have the mavlink option on (1)
Can AQ handle this? Maybe a "standard" serisl connection works?

MAVLink framing¶

If you set the MAVLINK option to 1 then the radio will do 'MAVLink framing'. The MAVLink protocol is used by APM for transmitting telemetry date to a ground station. When MAVLink framing is used, the radio will try to align radio packets with MAVLink packet boundaries. This means that if a packet is lost you don't end up with half a MAVLink packet being seen by the receiver. That partial packet would appear as line noise on your ground stations console.

The radio firmware will try to fit multiple MAVLink packets into one radio packet where possible for maximum efficiency. The highest radio packet size is 252 bytes.

The radio firmware supports both the MAVLink 0.9 and the MAVLink 1.0 transmission formats.

MAVLink reporting

If you have MAVLINK set to 1, then the radio firmware will also look for MAVLink HEARTBEAT messages coming from the serial connection. If it sees a HEARTBEAT message then it knows that the MAVLink protocol is in use, and it will start injecting MAVLink 'RADIO' status packets into the the serial stream.

The RADIO packets contain information about the RSSI (Received Signal Strength Indicator) level at both ends of the link, allowing the ground station or aircraft to take action in case the link quality falls too low.

The RADIO packets also contain information about error rates, and how full the serial transmit buffer is (as a percentage). The latest APM firmware can use this information to automatically adapt the telemetry stream rates to the data rate that the radios can sustain.

[afernan]

@chschmid:
thanks a lot for your explanations, that make sense.

I´ve tested again without Mavlink support in both Tx,Rx 3DR modules and they worked fine for QGC-Windows (always work there) but still not working in Android N7.
What could be the difference between XBee and 3DR on Android? (XBee works fine, 3DR not)

Angel

[kinderkram]

Sometimes it's a pita being a pioneer, Angel.
Sorry, but I can't help much since I use my netbook for the connection (Wi232 on the one AQ and BT on the other one).
If I'll find some time I'll dissamble the 3DR from my MWC copter to test the BT<->3DR connection.

Since you successfully connected the 3DR on your Windows you could try the same: Do a BT<->BT bridge for AQ6<->Win first, then the 3DR<->3DR for AQ6<->Win and finally try to get a connection like Win<->BT<->BT<->3DR<->3DR<->AQ6

But I'm pretty sure the problem is somewhere between BT and 3DR...

[skew]

I have been able to connect win/bt<->3dr---<3dr>AQ before just getting setup in case I bought a nexus 7 but I don't own any android devices to try. Its a catch 22 I sold my galaxy S3 to buy a AQ now I want an android device for the AQ LOL