I have modified my Multi_Blink example in the Playground to do the cool pattern you are looking for. Hope this helps.
Mulri_Blink2.h
// Multi_Blink2.h
//
// Blink lots of LEDs at diffreent frequencies simultaneously
//
// Header file is required to be able to define the structured types
//
#include <Arduino.h>
#ifndef MULTIBLINKH
#define MULTIBLINKH
// State values for FSM
#define MB_NULL 0
#define MB_LOW 1
#define MB_HIGH 2
#define MB_LOOP 3
#define LOOP_UNDEF 255
typedef struct
{
uint8_t activeVal; // state value for this state to be active (MB_* defines)
uint16_t activeTime; // time to stay active in this state stay in milliseconds or loop counter
uint8_t nextState; // If MB_LOOP this is the state to loop back/forward to
} stateDef;
typedef struct
{
uint8_t ledPin; // Arduino I/O pin number
uint8_t currentState; // current active state
uint8_t currentLoop; // current position in the cycle
stateDef state[5]; // the MB_* state definitions. Add more states if required
uint32_t nextWakeup; // the 'time' for the next wakeup - saves the millis() value
} ledTable;
#endif
Multi_Blink2.ino
// Multi_Blink2
//
// Blink lots of LEDs at different frequencies simultaneously, include delays and loops in patterns
//
// Marco Colli - September 2012
//
// Demonstrates the way to carry out multiple time based tasks without using the delay() function
// Demonstrates the use of structures (and structures within structures)
// Demonstrates a data driven approach to programming to create compact, reusable code
//
#include "Multi_Blink2.h" // type definitions
// Blink Table T - Modify this table to suit whatever the output requirements are
// Add or delete lines as required to achieve the desired effects.
// To add additional states the structure in the header file needs to be modified
//
ledTable T[] =
//Pin St Lopp State 0 State 1 State 2 State 3 State 4 Wkup
{
{ 13, 0, 0, {{MB_HIGH, 20, 0}, {MB_LOW, 50, 0}, {MB_LOOP, 3, 0}, {MB_HIGH, 250, 0}, {MB_LOW, 450, 0}}, 0 },
{ 12, 0, 0, {{MB_LOW, 450, 0}, {MB_HIGH, 20, 0}, {MB_LOW, 50, 0}, {MB_LOOP, 3, 1}, {MB_HIGH, 250, 0}}, 0 },
};
// Self adjusting constants for loop indexes
#define MAX_STATE (sizeof(T[0].state)/sizeof(stateDef))
#define MAX_LED (sizeof(T)/sizeof(ledTable))
void setup()
{
for (int i=0; i < MAX_LED; i++)
{
pinMode(T[i].ledPin, OUTPUT);
T[i].nextWakeup = 0;
digitalWrite(T[i].ledPin, LOW);
T[i].currentLoop = LOOP_UNDEF;
}
}
void loop()
{
for (int i=0; i < MAX_LED; i++)
{
// check if the state active time has expired (ie, it is less than current time)
if (millis() >= T[i].nextWakeup)
{
T[i].nextWakeup = millis() + T[i].state[T[i].currentState].activeTime;
switch (T[i].state[T[i].currentState].activeVal)
{
case MB_LOW:
case MB_HIGH: // Write digital value
digitalWrite(T[i].ledPin, T[i].state[T[i].currentState].activeVal == MB_HIGH ? HIGH : LOW);
T[i].currentState = (++T[i].currentState) % MAX_STATE;
break;
case MB_LOOP: // loop back to specified state if there is still count left
// first time in this state set the loop counter
if (T[i].currentLoop == LOOP_UNDEF)
{
T[i].currentLoop = T[i].state[T[i].currentState].activeTime;
}
// loop around or keep going?
if (T[i].currentLoop-- > 0)
{
T[i].currentState = T[i].state[T[i].currentState].nextState;
T[i].nextWakeup = 0; // do it immediately
}
else
{
T[i].currentLoop = LOOP_UNDEF; // set up loop counter
T[i].currentState = (++T[i].currentState) % MAX_STATE;
}
break;
default: // just move on - handles NULL and any stupid states we may get into
T[i].currentState = (++T[i].currentState) % MAX_STATE;
break;
}
}
}
}