Just to let everyone know, the problem at the end seems to have being the device.
The guys already sent a replacement that is on the way.
Thank you guys, really exited to get it soon.
As I had to do a lot of research I'll left the other possible things you can do if you are having issues with the Arduboy in Mac OS El Capitan, based on what I read all around:
- Check cables, people end up really surprised on when they were using a cable that worked for something else, but not the arduboy, use a decent cable specifically label for data transmission.
- Remember to turn it on.
- Make sure you connect it directly into the port not through a USB hub, some may give problems.
- Mac OS El Capitan has a new System Integrity Protection (SIP) which disable some functionalities with no signed Kext's and stuff like that, try disabling it (you can google the steps).
- Try it out with another computer, hopefully with a different OS
I hope that helps someone
Again, thanks to the guys in Arduboy