[Tinyos-help] link layer implicit used component

[Anton]

Hi,

if you use TinyOS 2.x and CC2420 radio:

in the folder \tinyos-2.x\tos\chips\cc2420\link there are several 
components responsible for the link layer. By default, the configuration 
PacketLinkDummyC is used (and therefore, "everything" is in 
PacketLinkDummyP, look through 
\tinyos-2.x\tos\chips\cc2420\CC2420ActiveMessageC.nc configuration). So, 
the link layer is actually involved in the radio communication process, 
but you do not refer it directly (you just call AMSend.send() command in 
your program).

If you want to perform link layer retransmissions, you should use 
PacketLink interface provided by CC2420ActiveMessageC (the corresponding 
wiring should be created in your top-level configuration), and you 
should #define PACKET_LINK in your program (look through 
\tinyos-2.x\tos\chips\cc2420\README.txt). After you have written all 
this in your program, the configuration PacketLinkC is used and the 
component PacketLinkP "provides" the link layer.

Anton.