In each 4 bits group, the first bit is the top arm, the second bit is the right arm, the third is the bottom arm and the fourth is the left arm (they go clockwise), when a bit is 1 you draw it's arm, when it is zero you don't; no need to actually draw the arms individually if you're using those characters though, since all the possible combinations already exist as unicode characters.


Btw, a correction regarding my base 8 suggestion, that one doesn't need a blank space since it's already 8 characters, the first one, the shortest of them, is zero and the highest one is 7; just like how in base 2 you use 0 to 1 and not 2, in base 8 you use zero to 7; i appologize for that slip.