Nano­RK And Zigduino

Nano­RK And

Zigduino

wnfa ta course

­­hikaru4

Today's outline

● Zigduino v.s. Firefly

● Atmel processor and the program chip

– Atmega128rfa1, FTDI chip...

● I/O Interface on the board

– GPIO, ADC, UART, SPI, I2C...

● Nano­RK

● Nano­RK OS Architecture

● Nano­RK HOW­TOs

● Tips and Tricks

● Lab2 announcement.

Zigduino

History

● Firefly

● CMU

● Firefly1.0

● Firefly2.2

● Firefly2.3

– no longer manufacture

● Firefly3.0

– Not release yet

– atmega128rfa1

● Zigduino

● logos­

electro.com

● Arduino­compatible

– Arduino is an open­

source electronics  prototyping platform.

● Atmega128rfa1

– The same one as  firefly3's

Zigduino

● Atmega128rfa1

● FTDI

● Clock Speed 16 MHz

● Flash Memory 128 KB 

● SRAM  16 KB

● EEPROM 4 KB

● Radio 802.15.4(zigbee)

I/O interface

● GPIO(pin2~10)

● ADC(analog in 0~6)

● UART(RX, TX pin0,1)

● SPI(11 (MOSI),    12 (MISO),       13 (SCK))

● I2C(I2C SDA, SCL)

GPIO

● General Purpose  Input/Output

● Pin2~10

● Digital input

● Digital output

● Control direction  by some selector

GPIO

● Tri­state Buffer Port

● Memory­Mapped IO

● Control Registers

● Data Direction Register (DDR, TRIS)

● Internal Pull Up Register (PLP)

● Reading / Writing to the Port

GPIO

● Example

● LED, buzzer,

7­segment display

– http://www.youtube.com/watch?v=fIjj6yDIe40

● Switch, button

– http://www.youtube.com/watch?v=qxJvsL6ES0k

ADC

● Analog to Digital  Converter

● ANALOG IN 0~6

● Analog input

● Converts an Analog  Signal to a Digital One

● 10 bit Resolution

ADC

● Example

● Sensor: Light sensor, temperature sensor....

UART

● Universal Asynchronous Receiver / Transmitter

● RX, TX (pin0,1)

● Serial port 

communication

UART

● RX­>TX

● TX­>RX

● Baud rate

UART

● Example

● Open log, T07AW, GPS module...

SPI and I2C

● SPI(11 (MOSI),    12 (MISO),       13 (SCK))

● I2C(I2C SDA, SCL)

● Serial bus protocol

SPI(Serial Peripheral Interface)

● 4 Wire Serial Bus from Motorola

– MISO/MOSI <=> RX/TX

– SCLK => baud rate

– SS => slave select

I2C(Inter­Integrated Circuit)

● Multi­drop 2 wire  serial bus protocol from Philips

– SCL: Serial Clock

– SDA:Serial Data Line

● Two Bi­directional Open­Drain Lines

Data transfer is initiated with the START bit (S) when SDA is pulled low while SCL stays high. Then, SDA sets the transferred bit while SCL is low (blue) and the data is sampled (received) when SCL rises (green). When the transfer is complete, a STOP bit (P) is sent by releasing the data line to allow it to be pulled up while SCL is constantly high.

Nano­RK

What is nano­RK?

● A Real­time Operating System for sensor  nodes for use in wireless sensor networks

● Priority­Based Preemptive Multitasking

● Resource Reservations

Nano­RK feature

● C GNU tool­chain

● Classical Preemptive Operating System Multitasking  Abstractions

● Real­Time Priority Based Scheduling

● Built­in Fault Handling

● Energy Efficient Scheduling based on a­prior task­set  knowledge

● Tickless Timer

● Small Footprint (<2K RAM, 16K ROM, including link  layer) 

Nano­RK Motivation

● Why Priority­based scheduling?

Time­triggered task interleaving can become  daunting...

Period  Execution Time Network Radio Sporadic 10ms

Audio Sensor 200 hz 10us Smart Camera  1 hz  300ms Global Positioning  5 hz 10ms

Nano­RK Reservations

● CPU Utilization

● Time Allowed Per Period

● For example, a task can run for 10ms of time  every 250ms

● Network Utilization

● Packets In and Out Per Period

● Sensors & Actuators Usage

● Sensor Readings Per Period

Nano­RK Architecture 

Nano­RK Time Management

● ~1ms OS Tick Resolution

● Variable Tick Timer (interrupts occur as required, not  every quantum)

● wait_until_xxx() functions

● Suspend task until the event or timeout happens

● If there is no wait_until_xxx() call, then your reserve  will be violated

● If reserves are disabled, then this can starve low  priority tasks and will waste battery power

Creating a Nano­RK Task

NRK_STK TaskOne_Stack[NRK_APP_STACKSIZE];

nrk_task_type TaskOne;

void Task1(void);

...TaskOne.task = Task1;

nrk_task_set_stk( &TaskOne, TaskOne_Stack, NRK_APP_STACKSIZE);

TaskOne.prio = 2;

TaskOne.FirstActivation = TRUE;

TaskOne.Type = BASIC_TASK;

TaskOne.SchType = PREEMPTIVE;

TaskOne.period.secs = 0;

TaskOne.period.nano_secs = 100*NANOS_PER_MS;

TaskOne.cpu_reserve.secs = 0;

TaskOne.cpu_reserve.nano_secs = 10*NANOS_PER_MS;

TaskOne.offset.secs = 0;

TaskOne.offset.nano_secs= 0;

nrk_activate_task (&TaskOne);

Nano­RK Fault Handling

● Task Time Violations

● OS will enforce time bounds given to a task

● Canary Stack Check

● Check if user­specified stack has been overflowed

● Not 100%, but incurs low overhead and better than nothing

● Unexpected Restarts

● Capture restart that occurs without power­down

● Resource Over­use

● Manage sensors / actuators

● Low Voltage Detection

● Watchdog Timer

Configure Nano­RK (nrk_cfg.h)

#define NRK_REPORT_ERRORS // print error over serial

#define NRK_HALT_ON_ERROR // stop the kernel on error

#define NRK_STACK_CHECK // Enable Canary Stack Check

#define NRK_NO_POWER_DOWN // zigduino need this define

#define NRK_MAX_TASKS 2

// Max number of tasks in your application

#define NRK_MAX_RESOURCE_CNT 1

// The number of semaphores in the system.

#define NRK_TASK_IDLE_STK_SIZE 64 // Idle task stack size min=32

#define NRK_APP_STACKSIZE 128

#define NRK_KERNEL_STACKSIZE 128

Take a break

● Next coming:

● Soldering

● Nano­RK how­tos

– API, debug tips

● Nano­RK learning by doing

Soldering

● Some tutorial

● http://www.youtube.com/watch?v=q_­xLuGPhzk

● http://v.youku.com/v_show/id_XMjMwMTUyNDU2.html

Nano­RK API Quick Guide

● How to find the API you need?

● Take a look of sample code

– In folder: nano­RK/project/

● Go official API document

– http://www.nanork.org/wiki/Documentation

● Trace the source code

– http://mvnl.csie.ntu.edu.tw/nano­RK/HTML/

● Write one!!! (you will need the datasheet)

– http://ppt.cc/Q2~L

Nano­RK API Quick Guide

● Example:

● svn://mvnl.csie.ntu.edu.tw/wn11fall/lab/examples/

● led_blink

– nrk_gpio_direction()

– nrk_gpio_set(), nrk_gpio_clr(), nrk_gpio_toggle()

● basic_tasks

– nrk_task_type

Nano­RK Debug?

● printf() is your good friend

● You will need a serial console.

– Unix like: minicom

– Windows: teraterm, putty, hyperterm...

● Remember printf is slow.

● LED is your good friend

● pin13 = L, RFRX, RFTX

● plug more LEDs on GPIO

● much faster then printf() 

Nano­RK Tips and Tricks

● Tip 1. NO MORE UP arrow!!!

● “$ make clean && make && make  program || make program”

● Save your time from typing and typing  again during debugging.

(Or press UP arrow again and again).

Nano­RK Tips and Tricks

● Tip 2. NO MORE vim makefile!!!!

● “$ make clean ROOT_DIR=~/nano­RK”

● “$ make ROOT_DIR=~/nano­RK”

● “$ make program ROOT_DIR=~/nano­Rk/nano­RK  PROGRAMMING_PORT=/dev/ttyUSB0”

● Don't waste your time to edit the makefile anymore.

Nano­RK Tips and Tricks

● Tip 3. No MORE ctrl+a o!!!!!

● “$ LANG=C ;minicom ­o ­D /dev/ttyUSB0”

● Don't waste your time to setup the minicom  anymore.

Nano­RK Tips and Tricks

● Tip 4. Where is my warning/error??????

● “$ make 2>&1 | grep main.c:”

● “$ make 2>&1 | egrep 'main.c:|

myinclude.c'”

● Get your warning/error messages only.

Lab2

Zigbee RSSI localization

Lab2:  zigbee RSSI localization

● Path loss exponent : step by step

● Get distance from RSSI

● Localization

● The nodes we set at CSIE 2F

● What you need to do

● Path loss exponent

● Localization algorithm

Path loss exponent

● Free space:

P_r =  

4d ^

2

⋅P_t , P_r ∝  1 d ^

2

 10logP_r = −2⋅10logd^c

 P_rdBm ^{= −}2⋅d_dBunit^c

Path loss exponent

● Log­distance path loss model:

P_r ∝  1 d ^

n

 10logP_r^{ = −}n^⋅10logd^c

 P_rdBm ^{= −}n^⋅d_dBunit^c

Receive power v.s. Path loss

● Path loss:

PL ⁼ P_t

P_r ^{∝ }d^n

 10logPL^{ =} n^⋅10logd^c

 PL_dB ⁼ n^⋅d_dBunit^c

Path loss exponent

P_r ^{∝  1} d ^

n P_rdBm ^{= −}n^⋅d_dBunit^c

RSSI to distance

P_r ^{∝  1} d ^

n P_rdBm ^{= −}n^⋅d_dBunit^c

localization

The node we set at CSIE 2F

What you need to do?

● Path loss analysis

● Measurement the RSSI with different distance

● Take log scale

● Draw the regression line of path loss

What you need to do?

● Design the localization algorithm

● Base on RSSI

● Real time localization

● Demo

● We will announce the free time slots of the TAs.

Q&A

●

Any questions?