Wireless Gamecontroller With Arduino and NRF24L01+ (support for One or Two Controllers)

You can find the complete project from my website (it's in Finnish): https://teukka.webnode.com/l/langaton-ohjain-atmega-lla-ja-nrf24l01-radiomoduulilla/

This is a really short briefing about the project. I just wanted to share it if someone would like to build it and can't read Finnish.

Have you ever thought about playing web-based games with your friend, but the mapping is so bad that you have hard time playing it? Worry not, because you can build your own controller with custom mappings. I coded the controller to emulate a USB-keyboard, but you can use it as whatever you want.

Step 1: Parts

This is the hardware you will need:

2 pcs of Arduino Pro Mini (ATmega328P or something else will do)
2 pcs of NRF24L01+ modules for the wireless communication
Arduino Leonardo or Arduino Pro Micro (receiver)
3D printed chassis (link below for the files)
ISP programmer or USB -> RS232 converter to program the controllers
16 pcs of 20*20 mm buttons
2 pcs of Li-ion batteries for the controllers (REMEMBER PROTECTION CIRCUITS! You don't want to kill yourself! I recommend the TP4056-board which has USB-charing and protection in the same board!)
2 pcs of small slide switches (something like SS12D00G3)
A lot of wires
Dupont connectors (optional)

You can find the Fusion 360 model from here: https://a360.co/2QPYNe4

Step 2: Coding

Then just program the controllers (gamecontroller_dualcontroller.ino for the controllers if you want to use two controllers and gamecontroller.ino if you want to use only one) and the receiver (gamecontroller_dual_receiver_w_keystrokes.ino for two and gamecontroller_receiver_w_keystrokes for only one controller)

However you have to give the controllers different addresses. Just open the radioLink.ino and change the line 22 for the first controller to this:
radio.openWritingPipe(address[0]);

And for the second controller to this:
radio.openWritingPipe(address[1]);

If you want to change the mapping, change the mapping[8] array (or mapping2[8] for the second controller).

You can find the codes from my GitHub: https://github.com/Teneppa/gamecontroller

Step 3: Assembly

How to assembly the controller:

Add necessary connectors to the charging circuit (and the switch to shut it down)
Glue the charging circuit to the bottom part
Add the switch and glue it in place
solder the NRF24L01+ to the Arduino (CE to pin 7 and CSN to pin 8)
Connect the buttons (another pin to ground and another to corresponding I/O pin, you don't really need the capacitors)
Close the enclosure

How to assembly the receiver: