Download or clone the whole firmware and navigate to the keyboards/DeltaSplit75 directory. Once your dev env is setup, you'll be able to generate the default .hex using:
```
-$ make V2
+make V2
or
-$ make ProtoSplit (if you have one of the prototype PCBs)
+make ProtoSplit-ProtoSplit (if you have one of the prototype PCBs)
```
You will see a lot of output and if everything worked correctly you will see the built hex files:
```
-DeltaSplit75_ProtoSplit_Default
+DeltaSplit75_ProtoSplit_ProtoSplit.hex
or