Forum Menu




 


Log in Problems?
New User? Sign Up!
AVR Freaks Forum Index

Post new topic   Reply to topic
View previous topic Printable version Log in to check your private messages View next topic
Author Message
spincraft
PostPosted: Oct 09, 2012 - 04:28 AM
Wannabe


Joined: Sep 09, 2010
Posts: 85
Location: san diego CA US

LwMesh might be a good topic for the Atmel Tech. on Tour series. What is the possibility of that happening?

_________________
Asking a better question, is the beginning of learning.
**********************
New Hardware Hackers SIG in San Diego, CA Meets 2nd. Tuesday, more info www.Spincraft.com
***********************
 
 View user's profile Send private message  
Reply with quote Back to top
alexru
PostPosted: Oct 09, 2012 - 04:33 AM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

There is always a possibility, but I have not heard of any active preparations.

_________________
The opinions and views expressed by me on this forum are my own and do not represent my employer or anyone else that I'm affiliated with.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
uracolix
PostPosted: Oct 15, 2012 - 04:01 PM
Hangaround


Joined: Jun 17, 2008
Posts: 488
Location: Meissen, Germany

Alex, does LW mesh relies on any patents?
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
alexru
PostPosted: Oct 15, 2012 - 05:21 PM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

Not to my knowledge.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
uracolix
PostPosted: Oct 15, 2012 - 09:10 PM
Hangaround


Joined: Jun 17, 2008
Posts: 488
Location: Meissen, Germany

Thank you for the quick response, I had the same impression but I just want to ask. For sure it would be stated somewhere in the document or in the source code.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
linitrofe
PostPosted: Oct 16, 2012 - 03:12 AM
Newbie


Joined: Mar 20, 2007
Posts: 18
Location: Valparaiso, Chile

Alex:
There is any performance or benchmark tests for lwmesh?
 
 View user's profile Send private message  
Reply with quote Back to top
alexru
PostPosted: Oct 16, 2012 - 05:43 AM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

What kind of benchmarks? It performs the way I would expect it to on a normal applications. I have not tried to push it to the limits - I'm not a big fan of pushing stuff to the limits and I've never seen actual requests to do so.

PS: But no, there are no formal benchmarks, because it is hard to benchmark wireless stack. It is mostly limited by the medium, not by the software.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
dcraw101
PostPosted: Nov 02, 2012 - 04:03 PM
Newbie


Joined: Dec 12, 2007
Posts: 14


In the release notes it looks like only the 2.4GHz ZigBits are supported. Will lwmesh work with 900MHz zigbits?
 
 View user's profile Send private message  
Reply with quote Back to top
alexru
PostPosted: Nov 02, 2012 - 04:08 PM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

There are no projects for ZigBit 900, but it is very easy to make it work by changing projects for ZigBee 2.4 GHz to include rf212 PHY.

_________________
The opinions and views expressed by me on this forum are my own and do not represent my employer or anyone else that I'm affiliated with.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
tasosgi
PostPosted: Jan 11, 2013 - 12:24 PM
Newbie


Joined: Sep 16, 2011
Posts: 3


What about the power consumption? Can all the node oparate with battery? Can all the nodes go to sleep mode?
 
 View user's profile Send private message  
Reply with quote Back to top
alexru
PostPosted: Jan 11, 2013 - 04:49 PM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

Yes, you can. Non-routing nodes are designed for this reason. You can have routing nodes sleeping as well, but it is application responsibility to keep track of when nodes sleep and when not so that network stays operational and no nodes required for routing are asleep.

_________________
The opinions and views expressed by me on this forum are my own and do not represent my employer or anyone else that I'm affiliated with.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
hlias0
PostPosted: Jan 14, 2013 - 12:34 PM
Newbie


Joined: Apr 28, 2011
Posts: 6
Location: Athens, Greece

Quote:
It should be possible to run them on ATMega32 with minor modifications, but not inside Arduino environment.

Just out of interest, why do you think it is not possible to port LwMesh to arduino environment?

They both use a form of cooperative multitasking, so in theory it should be possible to write a C++ wrapper class for the LwMesh C code. Then replace HAL with Arduino calls for uart/spi etc?
 
 View user's profile Send private message  
Reply with quote Back to top
alexru
PostPosted: Jan 14, 2013 - 04:43 PM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

If amount of work required is fine with you, then it is possible to run LwMesh on Arduino.

_________________
The opinions and views expressed by me on this forum are my own and do not represent my employer or anyone else that I'm affiliated with.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
dcraw101
PostPosted: Jan 25, 2013 - 10:49 PM
Newbie


Joined: Dec 12, 2007
Posts: 14


It looks like each node needs to have a unique 16 bit address. Is there any way to auto assign addresses or is it the responsibility of the application to ensure unique addresses via special programming, switches, etc? Is there any way to take advantage of a Maxim DS2411 chip that automatically provides a unique 64 bit address?
 
 View user's profile Send private message  
Reply with quote Back to top
alexru
PostPosted: Jan 26, 2013 - 12:53 AM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

Application should take care of address assignment, there are no mechanism defined by the stack. Depending on the complexity of your application it might be as simple as assigning a random number.Just make sure it is truly random, otherwise all devices will pick the same address. Using UID chip value to seed random number generator is one way of doing this.

Another way is to simply take lowest 15 bits of the UID value and assign it to the address.

If your application is complex and you need to make sure that there are no conflicts, you'll have to implement some kind of centralized database and make one device assign addresses to everyone else.

_________________
The opinions and views expressed by me on this forum are my own and do not represent my employer or anyone else that I'm affiliated with.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
uracolix
PostPosted: Jan 28, 2013 - 09:04 AM
Hangaround


Joined: Jun 17, 2008
Posts: 488
Location: Meissen, Germany

In uracoli we use a technique for address assignment, that uses
the last 16 Byte of the bootloader section to store information like addresses, default channel, default pan id. The memory at the end of the bootloader is a more secure place then the eeprom, unless you flash with an external programmer.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
dcraw101
PostPosted: Jan 28, 2013 - 05:00 PM
Newbie


Joined: Dec 12, 2007
Posts: 14


Is there any way to detect address conflicts? Will the stack deliver a message to the application layer if the source address matches the destination address?
 
 View user's profile Send private message  
Reply with quote Back to top
dcraw101
PostPosted: Feb 01, 2013 - 08:38 PM
Newbie


Joined: Dec 12, 2007
Posts: 14


I have a test application that is working fine without security. After I enable AES security my receive data handler is still called, but now the NWK_DataInd_t.size is 4 bytes larger than expected and NWK_DataInd_t.data contains random values. Do I need to call some stack functions to explicitly encode and decode packets?. I enabled AES security on my RF212 using
Code:

#define NWK_ENABLE_SECURITY
#define SYS_SECURITY_MODE 0
NWK_SetSecurityKey("TestSecurityKey0")
 
 View user's profile Send private message  
Reply with quote Back to top
hobbss
PostPosted: Feb 28, 2013 - 07:20 PM
Resident


Joined: Oct 06, 2010
Posts: 846
Location: Chicago

Not sure if you're still checking this thread, dcraw, but here's my answer to your question.

I am somewhat new to the LwMesh stack, so would appreciate it if someone else (AlexRu) comments if I am wrong.

I believe the four extra bytes are the MIC (Message Integrity Code). See section 4.1 on p. 9 of AVR 2130 for a reference to the optional MIC. It is optional in the sense that it is only there if encryption is enabled.

I am not sure how to decode the MIC, or even if we are supposed to. Is it some sort of checksum that we can unroll to verify the message was received intact?

_________________
“Science is not consensus. Science is numbers.”
 
 View user's profile Send private message  
Reply with quote Back to top
alexru
PostPosted: Feb 28, 2013 - 07:26 PM
Raving lunatic


Joined: Apr 15, 2009
Posts: 6135
Location: San Jose, CA

dcraw101 wrote:
Is there any way to detect address conflicts? Will the stack deliver a message to the application layer if the source address matches the destination address?
For some reason I did not receive notification for this question even tough I'm watching this thread.

There is no way to detect conflicts using only the stack itself. If conflicts are possible, then you need to include some unique value (UID) in the message and check pair (UID, Addr) on the application level.

Messages addressed to self will not be delivered.
 
 View user's profile Send private message Send e-mail Visit poster's website 
Reply with quote Back to top
Display posts from previous:     
Jump to:  
All times are GMT + 1 Hour
Post new topic   Reply to topic
View previous topic Printable version Log in to check your private messages View next topic
Powered by PNphpBB2 © 2003-2006 The PNphpBB Group
Credits