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Tuesday, August 19, 2014

Let's make Wireless Gamepad / Controller for Famicom / NES Part 2: Hardware

What hardware do I need to get this project done faster? I need 2.4Ghz transceiver module which I can connect microcontroller to. The same module for a gamepad and receiver. I need very small and thin module to fit inside a gamepad case.
I thought to use ever popular module with NRF24L01 transceiver ic. But I don't have small one, one with 8 2.54mm pin connector is huge and will never fit inside a gamepad.

But I do have really small module with NRF24L01 clone ic called BK2421 (made by BEKEN). Module called RF-2400-NANO made by INHAOS Technology Co. This will fit nicely. It has the same configuration registers, but has 2 register banks. Second bank is only to configure BK2421 ic.

OK. Now I need a microcontroller to make it all work. I have 2 spare MSP430G2452 in VQFN package. This is enough to make proof of concept.

Also I need a battery for gamepad, lithium rechargeable battery. I will use MCP73831/2 charging ic from Microchip to charge this battery from USB.

In the next part I'll make schematics for transmitter and receiver modules.

Sunday, August 10, 2014

Let's make Wireless Gamepad / Controller for Famicom / NES Part 1

I'm slowly restoring good old Famicom console.
It was in partly working condition. Some games was able to show title screen but not start, or not start at all with grey screen. This was hard to find fault. But I managed to fix it, it was one of the address lines trace broken in the inner pcb layer. Added one wire and got it working.

Now to the topic.
Who need wires this days right? Less wires is better always. So I decided to design and make a mod for stock Famicom controllers to make them wireless.
Famicom has official wireless controllers but they were using crappy IR and you need to point it to console every time. I want to make RF wireless controllers using that fancy 2.4GHz ISM band.

I'll make a prototype for a newage Famiclone console to test things out (chinese D99 model, single chip clone).
This projects has two sub-projects. First one is for transmitter which will be inside Famicom controller with battery and USB charger. Second one is for receiver, prototype will use Famiclone controller port (Famiclone has removable controllers), you just plug in receiver or plug in wired controller.

Famicom controller has pretty simple schematics. It's a single shift-register parallel input, serial output and 8 pull-up resisters. It can use HEF4021B ic or similar. Famiclone controller uses black blob ic, which is unknown, it's the same shift register but with built-in pull-up resistors.
Stock controller schematics should look like this:

To make a transmitter I need to "read buttons" like a console, pack it into a packet and send it to receiver. To make receiver "plug and play" it should emulate controller. When packed received and when console read buttons it will respond as controller.

In the next part I will select hardware for transmitter and receiver.