Hackaday article jumbo-leds-make-for-a-handy-attiny-beacon/

Based on Kingbright Jumbo LED DLC-6SRD
In this monster led is 6 leds, why power all together? individual control is more fun

Controlled with charlieplexing with 3GPIO from AtTiny10 

Check 20mm led family ...

TO DO:

- try another colors .... blue, green ... green/ red (3x red 3x green)
- more power save code, with sleep

Source is simple ...

#include <avr/io.h>
#include <stdint.h>

int main (void) {
DDRB = 0b0111;         // Equivalent to pinMode

while (1)
{
led (1,2);
led (4,1);
led (2,1);
led (2,4);
led (4,2);
led (1,4);
}

}

void led (char plus, char minus)
{
 DDRB = 0b0111;         // all input;
 DDRB = plus | minus;
 PORTB = plus;
 PORTB = minus;
  delay (100);
}
void delay (int millis) {
  for (volatile unsigned int i = 34*millis; i>0; i--);
}