Asctec Pelican atom board connection

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Asctec Pelican atom board connection

Steven Bellens
Hi,

I've been experimenting with this Atom expansion board some time ago,
but never really got to the point of connecting it to the helicopter.
Digging in my e-mail archive, I found some e-mail of Stefan explaining
me how to do so:

"If you like to use the Atom board in between I recommend to use the
serial cable between IMU and Atom board to link these two and to use
the Wi-Fi to interact with the ground station."

Apologies to you, Stefan, for not following this up, as I had other
priorities at that time. By now, I think this mailing list is more
appropriate, hence my question here:

How do I connect this board to the Pelican helicopter and read out the
data structs?
I already have a wi-fi connection set-up for communication with the
ground station.
I found this little wire in the Pelican box going from mini-usb to
some small grey connection (I'm not familiar with that type) which
seems to plug in one of the helicopter main boards plugs. Is this the
one I need to use? If so, than how do I access the data structs? If
not, what else is available? :)

regards,

Steven
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Re: Asctec Pelican atom board connection

Bill Morris
Administrator
On Tue, 2011-02-15 at 10:48 -0800, Steven Bellens [via asctec-users]
wrote:

> Hi,
>
> I've been experimenting with this Atom expansion board some time ago,
> but never really got to the point of connecting it to the helicopter.
> Digging in my e-mail archive, I found some e-mail of Stefan
> explaining
> me how to do so:
>
> "If you like to use the Atom board in between I recommend to use the
> serial cable between IMU and Atom board to link these two and to use
> the Wi-Fi to interact with the ground station."
>
> Apologies to you, Stefan, for not following this up, as I had other
> priorities at that time. By now, I think this mailing list is more
> appropriate, hence my question here:
>
> How do I connect this board to the Pelican helicopter and read out
> the
> data structs?
> I already have a wi-fi connection set-up for communication with the
> ground station.
> I found this little wire in the Pelican box going from mini-usb to
> some small grey connection (I'm not familiar with that type) which
> seems to plug in one of the helicopter main boards plugs. Is this the
> one I need to use? If so, than how do I access the data structs? If
> not, what else is available? :)

You need to connect the serial port on the atom board to replace the
XBee connection.

http://robotics.ccny.cuny.edu/wiki/AscTec/Docs
If you look at the carrier board manual on page #4 you will see where
the serial ports on the Atom board are located.


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Re: Asctec Pelican atom board connection

Andi Ruesch
Hi there,

I've just started to work with the Pelican and the Atom Carrierboard. During the setup-phase, the same question popped up. And I still don't really understand how to connect the Autopilot to the Atom and unfortunately I didnt found any documentation about this!

On the atom side: does it matter which UART port I use?
on the autopilot side: where to connect? on one of the LL/HL serial ports?
which cable is to use? In the Pelican box I found the following three serial cables:
- Atomboard -> AP/PEL Connection Cable
- Atomboard Bootloadercable
- AscTec Usb & AP/Pel Bootloadercable

Thx a lot,
Best regards
Andi Ruesch

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Re: Asctec Pelican atom board connection

ivan Mondragon
In reply to this post by Steven Bellens
Dear

We had this problem some months ago and we solve in the following way.

On the AtomBoard there is cable that allow to connect the UART (10 pins ) to the Autopilo LL or HL serial ports (6 pins)

In our case, The Autopilo LL serial 0 is connected to the Xbee, the LL serial 1 to the RC, the HL serial 1 to the GPS and the HL serial 1 is connected also to the RC but only on the voltage input (6 or 3 V)

So. what we do in order to connect.

We modify the given cable 6 to 10 pin, in order to be connected from Atom UART 0 to the Autopilot HL serial 0.

because in serial communication is only necessary the TXD, RXD, the other pins are still available. So at the end we have a modified 10 to 6 pin connected on the following way

10 pins-> atom UART 0 or 1.
6 pin side:
 txd, rxd -> connected to the Atom 10 pins
 cts -> open
3.3 or 6 (I don't remember ) -> to RC input cable
gnd->open

In this way you can have the following configuration
LL serial 0- Xbee to ground
LL serial 1 ->RC
HL serial0 -> two cable to Atom UART and 1 cable to RC voltage input.
HL-serial 1 -> gps

In this way, you are connected, but you can't do anything. So you have to use the AscTec SDK (eclipse) and add your own functions to the High Level, in order to communicate internally with the low level. You can create your own structures and functions that writes and read info from the Low Level and in this way you can send direct motor commands or pitch, roll, yaw and thrust commands.

In our implementation we send commands from the Atom board and also recive our own package with the Pelican state. However because have a large package we can not have a frequency higher than 15 or 20 fps. (at higher frequencies you note that your GPS reading is slow, and position control some time make small jumps) but Ascending tell me that if you write correctly you own functions it is possible higher frequencies.

Regards

Ivan      
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Re: Asctec Pelican atom board connection

Shahid Banglawala
In reply to this post by Steven Bellens
Dear all,

Some useful information here, thanks! I took found little in the documentation about communication between the Atom board and Autopilot pilot board.

I was wondering if anyone had any thoughts on what I want to achieve, my background is not software/hardware or electronics so I struggle in this area.

I would like to fit an Ultrasound sensor to a Pelican for height control purposes. I have a piece of code for Linux that can talk to the sensor fine and get data out of it. My question is how to take this data (height output in cm) from the Atom board, up to the autopilot processor and out of the XBee wireless link.

If I can achieve that, then I plan on using the new SDK with Matlab/Simulink to create a simple PID controller for auto takeoff/landing based on the ultrasound sensor height readings.

Your thoughts and help on the matter is highly appreciated!

Shahid
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Re: Asctec Pelican atom board connection

Aaron
Hi, Shahid

I know it's a little bit late to ask you some problem with the communication between the Atom board with Autopilot piolt board, but I'm trying to figure this out and I'm stuck on this probelm for few months. I know I need to use the ACI to do that, but how to send parameters from remote and how to receive the parameters in device, I really don't know.  Have you solved this problems?  Any suggestion will be appreciated.

Cheers,

Aaron
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Re: Asctec Pelican atom board connection

ettrikgator
In reply to this post by Andi Ruesch
<quote author="Andi Ruesch">

---I assume you are using the asctec image here.

On the atom side: does it matter which UART port I use?
--- you should use ttyUSB0 (port 0). ttyUSB1 is used for terminal login.

on the autopilot side: where to connect? on one of the LL/HL serial ports?

--- if you want to get information from HLP, then connect it to the HL serial 0.

which cable is to use? In the Pelican box I found the following three serial cables:

a cable with 10 pin connector on one end and an 6 pin connector on the other side. the 6-pin end
has a loop from CTS and GND, as Ivan suggested.

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Re: Asctec Pelican atom board connection

andre@asctec
In reply to this post by Aaron
Hi Aaron,

if you are speaking in terms of ACI, there is a tutorial for the ACI Device and the ACI Remote in our wiki: http://wiki.asctec.de/display/AR/AscTec+Communication+Interface

The ACI Remote in your case would be the Atomboard, whereas the AutoPilot is always the ACI Device. If you use the SDK3.0 for the AutoPilot the ACI is already fully integrated and ready to use.

The connection cable from your Atomboard (10pin to 6pin, with 2 wires) must be connected to the "HL Serial 0" port on the AutoPilot for the ACI to work. Check the pinout here: http://wiki.asctec.de/display/AR/Pinout+and+Connections

Cheers,
Andre
Andre Ryll
AscTec Application Engineer