Using ideas from:
- http://www.instructables.com/id/Creating-a-charlieplexed-LED-grid-to-run-on-ATTiny/
- http://makezine.com/projects/charlieplexing-leds-with-an-avr-atmega328-or-arduino/
- http://pcbheaven.com/wikipages/Charlieplexing/
Modified the code to match my circuit:
#define A 7
#define B 6
#define C 5
#define D 4
#define PIN_CONFIG 0
#define PIN_STATE 1
#define LED_COUNT 12
int matrix[LED_COUNT][2][4] = {
// PIN_CONFIG PIN_STATE
// A B C D A B C D
{ { OUTPUT, OUTPUT, INPUT, INPUT }, { HIGH, LOW, LOW, LOW } }, // AB 0
{ { OUTPUT, INPUT, OUTPUT, INPUT }, { HIGH, LOW, LOW, LOW } }, // BA 1
{ { OUTPUT, INPUT, INPUT, OUTPUT }, { HIGH, LOW, LOW, LOW } }, // BC 2
{ { INPUT, OUTPUT, OUTPUT, INPUT }, { LOW, HIGH, LOW, LOW } }, // CB 3
{ { INPUT, OUTPUT, INPUT, OUTPUT }, { LOW, HIGH, LOW, LOW } }, // AC 4
{ { OUTPUT, OUTPUT, INPUT, INPUT }, { LOW, HIGH, LOW, LOW } }, // CA 5
{ { INPUT, INPUT, OUTPUT, OUTPUT }, { LOW, LOW, HIGH, LOW } }, // AD 6
{ { OUTPUT, INPUT, OUTPUT, INPUT }, { LOW, LOW, HIGH, LOW } }, // DA 7
{ { INPUT, OUTPUT, OUTPUT, INPUT }, { LOW, LOW, HIGH, LOW } }, // BD 8
{ { OUTPUT, INPUT, INPUT, OUTPUT }, { LOW, LOW, LOW, HIGH } }, // DB 9
{ { INPUT, OUTPUT, INPUT, OUTPUT }, { LOW, LOW, LOW, HIGH } }, // CD 10
{ { INPUT, INPUT, OUTPUT, OUTPUT }, { LOW, LOW, LOW, HIGH } } // DC 11
};
void turnOn( int led ) {
pinMode( A, matrix[led][PIN_CONFIG][0] );
pinMode( B, matrix[led][PIN_CONFIG][1] );
pinMode( C, matrix[led][PIN_CONFIG][2] );
pinMode( D, matrix[led][PIN_CONFIG][3] );
digitalWrite( A, matrix[led][PIN_STATE][0] );
digitalWrite( B, matrix[led][PIN_STATE][1] );
digitalWrite( C, matrix[led][PIN_STATE][2] );
digitalWrite( D, matrix[led][PIN_STATE][3] );
}
void setup() {}
void loop() {
for( int l = 0; l < LED_COUNT; l++ ) {
turnOn( l );
delay( 100 );
}
}
And finally got this:
