TinyOS and UC Berkeley Motes

Hardware andProgramming Tools

Some slides and information was taken from Boot1.ppt and Boot2.ppt on the Berkeley TinyOS website. Some other information was taken from Lesson1 in the nest distribution

UC Berkeley Motes Many Types Current Version of TinyOS(TOS) supports

Mica Rene Dot

TinyOS flow Model

Interrupts

eve

nts

commands

Tasks

Example{... status = TOS_CALL_COMMAND(name)(args)...}

TOS_COMMAND(name)(args) {...return status;}

{... status = TOS_SIGNAL_EVENT(name)(args)...}

TOS_EVENT(name)(args) {...return status;}

TOS Component

A TOS component consists of an implementation and an interface, described by a .c file and a .comp file

Component Implementation

A TOS component implementation may contain a frame Event handlers Commands Tasks local procedures. 

The commands and events must match the commands and events it claims to accept in the interface.

TOS Component Frame Contains all the static variables for

the component Variables in the frames are

accessed by using the VAR macro.Examples of VAR macro:

x = VAR(superX);y = VAR(array)[VAR(index)].item;VAR(count)++;VAR(z) = 10;

TOS Command Declared as char TOS_COMMAND(cmd_name)

(cmd_param_list). Called called using

TOS_CALL_COMMAND(cmd_name)(cmd_args_list)

The return value is the status of the request: 0 => failure. 

A command may call commands, or post tasks, but may not signal events. 

It cannot block or spin waiting for state changes.

TOS event Declared as

char TOS_EVENT(evnt_name)(evnt_arg_list) Signaled using TOS_SIGNAL_EVENT(evnt_name)

(evnt_arg_list) Lowest level events are connect directly to

hardware interrupts by the system hardware abstraction layer. 

An event may signal events, call commands, or post tasks. 

It must complete in a short amount of time, bounded by the jitter requirements of the overall application.

.comp InterfaceTOS_MODULE name;

ACCEPTS{       command_signatures };

HANDLES{       event_signatures };

USES{      command_signatures };

SIGNALS{      event_signatures };

TOS Component Interface Implemented in .comp file Specifies the name of the component

module Describes

the set of commands the component accepts

the commands that the component uses the events that the component handles and the events the component signals

TinyOS Application A TOS application consists of a graph of

components A textual representation of this graph is

contained in the ) file for the application. The TinyOS component approach

separates creation of the components from their composition.  very easy to swap components in and out limits the interactions between components

to very narrow channels.

TOS Description File Specifies the set of component modules used

in the application and the wiring of commands and events across component interfaces. 

The wiring must be a subset of the interface elements associated with the components. 

There is a search path associated with resolution of module, typically consisting of "., tos/system, tos/platform, tos/shared". 

include modules{     module list };

connection list

Alternative output deviceinclude modules{

MAIN;

COUNTER;

INT_TO_RFM;

CLOCK;

};

MAIN:MAIN_SUB_INIT COUNTER:COUNTER_INIT

MAIN:MAIN_SUB_START COUNTER:COUNTER_START

COUNTER:COUNTER_CLOCK_EVENT CLOCK:CLOCK_FIRE_EVENT

COUNTER:COUNTER_SUB_CLOCK_INIT CLOCK:CLOCK_INIT

COUNTER:COUNTER_SUB_OUTPUT_INIT INT_TO_RFM:INT_TO_RFM_INIT

COUNTER:COUNTER_OUTPUT_COMPLETE INT_TO_RFM:INT_TO_RFM_COMPLETE

COUNTER:COUNTER_OUTPUT INT_TO_RFM:INT_TO_RFM_OUTPUT

apps/cnt_to_rfm.desc

CLOCK INT_TO_RFM

MAIN

COUNTER

cnt_to_rfm.desc expanded

CLOCK INT_TO_RFM

MAIN

COUNTER

hardware.h

hardware.h

AM

PACKETOBJ

SEC_DED_RADIO_BYTE

RFM

TinyOS Summary TOS_FRAME_BEGIN, TOS_FRAME_END to declare a component

frame VAR(foo) to access a variable (foo)

in the frame

TOS_COMMAND to declare a command TOS_CALL_COMMAND to call a command TOS_EVENT to declare an event

handler

TOS_SIGNAL_EVENT to signal and event

TOS_TASK to declare a task (part II) TOS_POST_TASK to post a task

TinyOS compiler tools tools/desc2objs

Generates the list of components that need to be compiled into an application

tools/mkheader Generates “C” header files from .comp files

tools/mksuper_desc Generates the super.h linkage file that wires

components together tools/mk_amdisp

Generates the mappings between handler ID’s and handler function names for the AM_MSG macro

Starting a Program By convention, TinyOS provides a MAIN

component which starts up on hardware reset and invokes an INIT command followed by a START command.  This allows the collection of components forming an application to come up cleanly.

The TOS_LOCAL_ADDRESS is also defined in the .c of this component

Implementation Details The .c file must #include the “tos.h” and

“NAME.h”. The .comp file must contain “TOS_MODULE

NAME” at the top. It must also have “JOINTLY_IMPLEMENTED_BY NAME” if the component has a .desc file, and the .desc is not the application .desc but a sub node.

Where NAME is the name of the component

Debugging Tools

LEDS dgb (which is printf basically) TOSSIM – TinyOS simulator

Packets Packets length can be specified

The default length is 36 bytes 4 bytes of header 30 bytes of data 2 bytes of checksum 2 bytes for signal strength

Reserved Addresses #define TOS_BCAST_ADDR 0xffff #define TOS_UART_ADDR 0x7e

Interpreting the Packet

struct MSG_VALS{short addr; (destination id)char type; (handler type)unsigned char group; (group id)char data[DATA_LENGTH];(data, length = 30) short crc; (check sum)short strength; (signal strength)

};