No the radio stack supports variable packet length.
The packet length is determined by the length field in TOS_MSG.
TOSH_DATA_LENGTH only determines the limit of your payload size.
-Han
roberto pagliari 提到:
I think the module CC2420RadioM send a payload (excluding headers and
footers) of
You don't need to check RSSI_VALID because you do not retreive the RSSI value.
The chip would handle the validity of RSSI and inform you whether the CCA check
is passed. The CCA check would return bad if the receiver has not yet been
enabled 8 symbol period.
-Han
- Original Message -
RSSI we measured? Averaged over the first 8 symbols or over
the full packet?
Regards, Aleksandr.
wbr, Sadkov Aleksandr
[EMAIL PROTECTED]
www.sumkino.com
www.wl.unn.ru
-Original Message-
From: Philip Levis [mailto:[EMAIL PROTECTED]
Sent: Monday, June 18, 2007 9:42 PM
To: Tsung-Han Lin
In TinyOS 1.x you can connect the interface HPLCC2420 to HPLCC2420C and use
call HPLCC2420.read(CC2420_RSSI);
to acquire ambient RSSI, make sure you check the RSSI_VALID register
before you read out the value.
To check that register you'll need to read the status byte, you can use
call
RSSI value is measured by the radio chip. CC2420 will append the rssi,
crc and lqi to the last two bytes of the packet.
You can refer to the CC2420 datasheet:
http://www.chipcon.com/files/CC2420_Data_Sheet_1_3.pdf
-Han
Aleksandr N. Sadkov 提到:
Hello All,
Could anybody explain how actually
-Original Message-
From: Tsung-Han Lin [mailto:[EMAIL PROTECTED]
Sent: Monday, June 18, 2007 3:07 PM
To: Aleksandr N. Sadkov
Cc: tinyos-help@Millennium.Berkeley.EDU
Subject: Re: [Tinyos-help] RSSI measuring
RSSI value is measured by the radio chip. CC2420 will append the rssi,
crc and lqi
Hi,
TOSBase does NOT transmit the strength (RSSI) thru UART.
You need to retrieve the strength value in TOSBase and store it
somewhere in your msg, and then you can see the value using any
kind of com port listener.
--Han
- Original Message -
From: CASTEL Myriam [EMAIL PROTECTED]
To:
LQI value is provided by CC2420. You can access the value in TOSMsg structure.
The variable name is lqi.
--Tsung-Han
- Original Message -
From: sangeeth kumar
To: tinyos-help@Millennium.Berkeley.EDU
Sent: Saturday, April 28, 2007 4:25 PM
Subject: [Tinyos-help] LQI in micaz
