Hello,

I need your suggestion in writing a program for the AVR butterfly which will drive a 7 element LED array to count up or count down

The 7-element LED has 7 LED’s physically laid out as follows:

0
1 2
3
4 5
6

Imagine these LED as being long and thin rather than circular. So the number 0 is displayed as:

on
on on
off
on on
on

The number 7 is displayed as:

on
off on
off
off on
off

The number 5 is displayed as:

on
on off
on
off on
on

A very basic way to do this would be as follows:


#define SEGMENT_0 (1<<SEGMENT_0_PIN)
#define SEGMENT_1 (1<<SEGMENT_1_PIN)
//repeat for all segments

#define OUTPUT_0 (SEGMENT_0|SEGMENT_1|SEGMENT_2|SEGMENT_4|SEGMENT_5|SEGMENT_6)
#define OUTPUT_1 //similar to aabove
//repeat for other numbers



When you want to output the value

void display(uint8_t value) {

switch(value) {
case 0: OUTPUT_PORT = OUTPUT_0;
break;
case 1: OUTPUT_PORT = OUTPUT_1;
break;
//etc up to case 9 or case F if you want hex
default: error_function(ERROR_CODE_DISPLAY_BOUND);

}
return;
}


I'm sure you could make more efficient code if you tried, but this is what i've got off the top of my head.
ps. this may not work, it's completely untested