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Author Topic: $59 wirless accelerometer with zigbee?!  (Read 1079 times)
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Hi All,

  I just found these freescale wireless accelerometers for $59 each (without the usb connection for the computer).  The website below says that they work with zigbee (if I'm reading it right).  Does this mean I can interface an arduino (with zigbee) with the wireless sensors without the usb connector?  If not, might it be possible to interface the sensors to an avr style chip?

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=RD3152MMA7260Q

I'm still a hardware noob, so any help would be great.




My primary idea is that I need two wireless accelerometers to connect to one or two arduino boards which will be emulating usb keyboards.  
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Glasgoow
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I have a ZSTAR kit as well and plenty of xbee modules and arduinos.
However I didn't have the need of interfacing it to the arduino shield.
If my memory doesn't trick me, these modules use zigbee protocol but they have a proprietary packet format in API mode which must be reversed by the C# library which i use to do the job.
I will give a better look at the documentation and find out if possible to connect them.
Cheers.
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Glasgoow
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I did some more investigations from the Datasheet!
The MC13213 System in Package (SiP) integrates the MC9S08GT MCU with the MC1320x transceiver
into a single 9x9mm LGA package. The MC13213 provides 60 K Flash memory and 4 K of RAM. By
using the IEEE 802.15.4 Compliant MAC, or BeeStack ZigBee Protocol Stack.
Specifically it's a ZigBee 2006 compliant platform.

Now about the packets, there is nothing to reverse.
The packet structure and command formats are available in the manual.
Code:
The ZSTAR3 uses a simple time based protocol for an RF transfer of information between sensor boards
and the USB receiver. The protocol is based on a simple star topology for a communication network, with
one master point (USB stick) and slaves (sensor boards). It provides time slots for up to 16 sensors. Main
data of a load contains acceleration (X, Y and Z axis) and basic status data. The protocol is built on top of
modified Section 5.2, Simple Media Access Controller (SMAC) drivers that are available for the
MC1319x and MC1321x transceivers families. It is bidirectional, allowing the set up of independent
connections for up to 16 ZSTAR3 demos, together in one RF space (thus, up to 256 sensor boards).
All data is transferred in so-called Zpackets. This protocol is primarily targeted at simple demo purposes,
allowing a fast transfer of the accelerometer data in short packets with minimum overheads and with
minimum battery loads (most of the receive windows eliminated, short transmit packets, etc.).

So basically the stack layer is organized as follow:

RF Zig bee <-> SMAC  <-> ZStar

As on Page 35 of the ZStarReference Manual.

Next step I will try to do a NodeDiscovery with my Xbee 2.5 series and see if it can see the sensors.

Another issue is that the NetNum is not related to the XBee address, so I have no idea how the MC is configured in terms of PAN and ID address.

Well if it doesn't work I guess you need to buy the usb key adapter!
:-)
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Glasgoow
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hi again,
I didn't manage to let them communicate using either ZNET or ZigBee API and transparent mode.
I also asked for support on the FreeScale forum  but since now nobody replied.
I suppose that considering the effort that you need  to put into programming a decoder/encoder you better buy the usb key and avoid all the shenanigans associated!

I'll you posted if somebody reply on the FreeScale dev. forum.
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Glasgoow
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If you are interested I did a simple shield for the arduino that plugs on top of the xbee shield.
There's an ADXL335 from sparkfun that you can buy.
I'm also designing an arduino shield which goes on top of the xbee shield with accelerometer + gyroscope,
Just to show you some pictures.




I also have a motion node with pcb already tested and designed with an xbee battery converter and accelerometer or gyroscope.

Lot of stuff to play with!
/me
« Last Edit: April 10, 2010, 04:54:43 pm by epokh » Logged

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