Raven

3 minute read

While doing research for possible master thesis topics, I’m looking into the idea of wireless sensor network. At KULeuven the DISTRINET research group is spending quiet some effort into this and I want to make sure that I fully understand it before I decide to move in this direction or not.

So I bought a Raven developer evaluation kit to see what it’s all about.

Step 1: Hello World

The developer evaluation kit basically comes with two Raven Wireless Sensor Nodes - let’s also call them motes, we need to talk the lingo now ;-) - and one USB stick to also allow a computer to join the network.

RZUSBSTICK

It seems that the RZUSBSTICK is recognized when I plug it into one of my Mac’s USB ports.

$ system_profiler SPUSBDataType | grep -A10 USBSTICK
RZUSBSTICK:

Product ID: 0x210a
Vendor ID: 0x03eb (Atmel Corporation)
Version: 2.00
Serial Number: A30100A01C25
Speed: Up to 12 Mb/sec
Manufacturer: ATMEL
Location ID: 0xfa135000 / 10
Current Available (mA): 500
Current Required (mA): 500

Now can I do anything with it? Turning on the Raven shows it’s not able to join any network. So I’ll need to do something more ;-)

Python

I found http://code.rancidbacon.com/LearningAboutAtmelRZRAVEN which included some Python code that should be able to setup the stick and connect to the mote.

I had to install libusb using MacPorts and use python also from MacPorts to get the script up and running:

$ ./raven.py 
=== Device found ===
Device:
'RZUSBSTICK'
Serial number: 'A30100A01C25\x00'
Traceback (most recent call last):
File "./raven.py", line 51, in <module>
handle.setConfiguration(config)
File "build/bdist.macosx-10.8-intel/egg/usb/legacy.py", line 257, in setConfiguration
File "build/bdist.macosx-10.8-intel/egg/usb/core.py", line 554, in set_configuration
File "build/bdist.macosx-10.8-intel/egg/usb/core.py", line 92, in managed_set_configuration
AttributeError: 'NoneType' object has no attribute 'bConfigurationValue'

Commenting out the line that sets the configuration, allows the script to continue, but it fails again a bit later:

$ ./raven.py 
=== Device found ===
Device:
'RZUSBSTICK'
Serial number: 'A30100A01C25\x00'
2
0x80
4
0x80
2
0x80
Traceback (most recent call last):
File "./raven.py", line 110, in <module>
response = handle.bulkRead(0x81, 50)
File "build/bdist.macosx-10.8-intel/egg/usb/legacy.py", line 159, in bulkRead
File "build/bdist.macosx-10.8-intel/egg/usb/core.py", line 661, in read
File "build/bdist.macosx-10.8-intel/egg/usb/backend/libusb1.py", line 541, in bulk_read
File "build/bdist.macosx-10.8-intel/egg/usb/backend/libusb1.py", line 648, in __read
File "build/bdist.macosx-10.8-intel/egg/usb/backend/libusb1.py", line 403, in _check
usb.core.USBError: [Errno 60] Operation timed out

Now, when I turn on a mote, it does connect to the network, so it seems that the partially working script initializes network on the stick.

After a bad night’s sleep, I started looking at the code again and compared it to http://pyusb.sourceforge.net/docs/1.0/tutorial.html. I’m not entirely sure, but I think the code was written in a pre-1.0 era, so I tried to convert it to the new coding style.

After learning a lot about Python, unicode, USB,… I managed to get the thing running. Most of the black-magic hexadecimal constants are still a mistery, but it works.

The code is @ https://github.com/christophevg/raven and it basically looks like this:

$ ./raven.py 
*** dumping configuration/interface/endpoint info
1
0,0
132
2
129
*** step 1: TODO: figure out what this does ;-)
if a USBError 60: Operation timed out happens here, reset the stick
2
0x80
*** step 2: setting channel=11 pan id= 0xBABE (TODO: figure out...)
4
0x80
*** step 3: final step to turn on network (TODO: figure out...)
2
0x80
*** network should be accessible now, turn on a mote
*** received response on control(?) endpoint
data = ['0x54', '0xc', '0x1b', '0x0', '0x1d', '0x81', '0x0', '0xa0', '0...'
*** remote address 0x001b joined.
*** sending message: Christophe was here ...
33
0x80
*** reading temperature
10
0x80
*** received response on control(?) endpoint
data = ['0x53', '0xa', '0x0', '0x0', '0x1b', '0x0', '0xff', '0x2', '0x0...'
*** received 0x53: ack for txt msg ?
9
0x80
*** reading temperature
10
0x80

Messages received by the mote are displayed … I need a shorter name ;-)

Christophe was here

Power

After only running a few tests, the pre-installed batteries are almost drained, so I’ll need to hook up some external power supply.

TODO

Step 2: Replace the existing code with something else

Before I acutally wipe the Raven, I want to know the basics and be able to replace the pre-installed code with a simple Hello World of my own.

TODO

Step 3: Install Contiki and Looci

The real goal is to install Contiki and Looci and start playing with that.

TODO

Temporary notes

  • sudo port install libusb
  • export PYUSB_DEBUG_LEVEL=debug
  • system_profiler SPUSBDataType | grep -A10 USBSTICK