meshlium code

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engmayarkamel
Posts: 17
Joined: Mon Feb 06, 2017 8:15 am

meshlium code

Post by engmayarkamel » Mon Feb 20, 2017 7:31 am

Dear Libelium

kindly i need to know if the meshlium code is authorized to use or only in specific sections and where i can find it, because i want to change some parameters to meet my requirements in the experiment. For instant, adjusting the time delay.

secondly i want to know what is the propagation model and unit of the RSSI , im getting values in positive and sometimes in negative, as far as i know if its in db it should be in negative.

thirdly for saving the database, i need to save for local area specific devices during the same day but i get all the devices with old dates also.

Thanks and Regards
Mayar Kamel

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: meshlium code

Post by libelium-dev » Mon Feb 20, 2017 8:17 am

Hi engmayarkamel,

Please can you tell us the Meslium model and your ManagerSystem version?

Regards

engmayarkamel
Posts: 17
Joined: Mon Feb 06, 2017 8:15 am

Re: meshlium code

Post by engmayarkamel » Mon Feb 20, 2017 9:46 am

Meshlium Scanner XBee 802.15.4 AP
Meshlium Manager System v.3.2.6

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: meshlium code

Post by libelium-dev » Mon Feb 20, 2017 11:05 am

Hi engmayarkamel,

- First question: You can modify the meshlium code at your own risk, also you void the warranty.


- Second question: RSSI can be used internally in a wireless networking card to determine when the amount of radio energy in the channel is below a certain threshold at which point the network card is clear to send (CTS).

An Atheros based card will return an RSSI value of 0 to 127 (0x7f) with 128 (0x80) indicating an invalid value. There is no standardized relationship of any particular physical parameter to the RSSI reading. The 802.11 standard does not define any relationship between RSSI value and power level in mW or dBm.
Vendors provide their own accuracy, but you there are formulas to convert those values to dBm online.

- Third question: Please perform these commands to check your current date values and try to find out a better solution:

Code: Select all

date

Code: Select all

date --utc

Code: Select all

hwclock --show
Log into your MySQL engine in your Meshlium and perform the following query:

Code: Select all

select now();
Please let us know your results.

Regards

engmayarkamel
Posts: 17
Joined: Mon Feb 06, 2017 8:15 am

Re: meshlium code

Post by engmayarkamel » Mon Feb 20, 2017 11:38 am

1)how can i access the mysql engine in order to make some changes in the code?
2) how to control the scanning time to be less than 10 sec from the wifi scan ---> capture local database

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: meshlium code

Post by libelium-dev » Mon Feb 20, 2017 1:42 pm

Hi engmayarkamel,

It is not necessary to log in into Meshlium if you want to change the scan interval, you can perform this action thru ManagerSystem, you can get this information on page 125 from our technical guide:

http://www.libelium.com/downloads/docum ... _guide.pdf

Regards

engmayarkamel
Posts: 17
Joined: Mon Feb 06, 2017 8:15 am

Re: meshlium code

Post by engmayarkamel » Wed Feb 22, 2017 6:48 am

Hello

Referreing to your answer for the sencond question:

(Second question: RSSI can be used internally in a wireless networking card to determine when the amount of radio energy in the channel is below a certain threshold at which point the network card is clear to send (CTS).

An Atheros based card will return an RSSI value of 0 to 127 (0x7f) with 128 (0x80) indicating an invalid value. There is no standardized relationship of any particular physical parameter to the RSSI reading. The 802.11 standard does not define any relationship between RSSI value and power level in mW or dBm.
Vendors provide their own accuracy, but you there are formulas to convert those values to dBm online.)


if the RSSI is below 0 is it also invalid value? and what is exactly the RSSI unit and what is the RSSI indicator?
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About the wifi scan in the meshlium i selected the scanning time to be 10 seconds, i want to know does meshlium wifi scan 1 RSSI every 10 second or it takes the average or it scan several RSSI in 10 sec.

Thanks

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: meshlium code

Post by libelium-dev » Wed Feb 22, 2017 8:29 am

Hi engmayarkamel,

RSSI 0 means no signal power, if you are gettign this value very often try to adjust your antennas.

If you set the scan interval to 10 seconds, that means Meshlium Scanner will look for devices (all devices available) each 10 seconds then it will stop 1 second and start scan again.

Regards

engmayarkamel
Posts: 17
Joined: Mon Feb 06, 2017 8:15 am

Re: meshlium code

Post by engmayarkamel » Wed Mar 01, 2017 11:42 am

Hi

what does -1 RSSI value means? i get this ( 2017-03-01 09:48:20 00:1E:C0:1B:7F:90 -1 Microchip Technology Inc. )

what is the range of RSSI?

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: meshlium code

Post by libelium-dev » Wed Mar 01, 2017 1:50 pm

Hi engmayarkamel,


RSSI is recorded in dBm. Higher values(ex: 50,70..200) means closer to the device and lower to negative values(ex: 1,0 or -2) means far from the device.

Regards

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