1 ->
2 -> dir1
3 -> dir2
4 ->
5 -> spindle on
6 -> step3-uclk
7 -> step1 - mosi
8 -> step2
9 -> dir3-reset
10 <- miso
11 <- tooltip sensor
12 <- x zero
13 <- y zero
14 ->
15 <- z zero
16 ->
17 ->

25 - gnd