“This project is an extension or remix of my original Portal Turret on Instructables (Portal-2-Turret-Gun). It can also be used as a cheap controller to control anything that uses the nRF24L01 radio chip. The LCD screen is particularly useful when customizing.
After I had completed the Portal Turret, I saw a short video clip of the Cara Mia opera scene at the end of Portal 2. I thought, “hey, I’ve built a few turrets now. I can do that!” Well, I had the turrets, but to make it work, they would now need to communicate with each other, or with some other device. After giving it some thought, and thinking that manual control would also be cool, I ended up deciding that I would build a Master Turret Controller, or an MTC.
Ok, so how to go about this? Well, I didn’t feel like modifying the turrets too much, so that was a constraint. I had some nRF24L01 radio chips which I hadn’t yet used, and thought that would keep in line with my goal of using inexpensive components and relying on mechanical design and code to make this work. I would have to build a controller and started mulling over what the controller would contain and what exactly I could do to the turrets. Cara Mia was already on the agenda, but what else?
Manual control: So once the wings are open, I would like to control the pitch and the pivot. 2 axes = a joystick, so joystick control and some push buttons. Push button 1 would fire the turret, and maybe push button 2 would make it say one of its sayings. Sounds good! Simple enough…
Chat: I recently saw the “Who’s on First” - Abbott and Costello routine again, and a light went off in my head! I would also make a sketch comedy routine using all of the sayings, using multiple turrets!! Ok, this one wasn’t fully figured out, but I’m sure I would get it sorted once my build was underway.
I also wanted this MTC to be wireless, so I opted for a simple 9V battery powered option and designed the controller to be powered by the mini-USB plug through the Nano at the back. Useful for updating too.”