#sega #controller #embedded-hal #genesis #mega-drive

no-std sega-controller

Embedded driver for reading Sega controller input

1 unstable release

0.1.0 Nov 4, 2022

#836 in Embedded development

29 downloads per month

MIT license

11KB
175 lines

Sega Controller Driver

crates.io

Embedded driver for reading input from Sega controllers in Rust.

This library utilizes embedded-hal traits as a platform-agnostic driver.

Features

  • mega-drive - includes Sega Mega Drive controllers
  • all - includes all available features

Example

use sega_controller::mega_drive::{MegaDriveButton, MegaDriveController};
use sega_controller::Error;

// Using some kind of hal like `arduino_hal`
// NOTE: You should have pull-up resistors on these pins (10k ohm)
let controller = MegaDriveController::from_pins(
    pins.d8.into_output(),          // select pin
    pins.d2.into_floating_input(),  // data pin 0
    pins.d3.into_floating_input(),  // data pin 1
    pins.d4.into_floating_input(),  // data pin 2
    pins.d5.into_floating_input(),  // data pin 3
    pins.d6.into_floating_input(),  // data pin 4
    pins.d7.into_floating_input(),  // data pin 5
);

// Only do this once every frame (16ms)
match controller.read_state() {
    Ok(state) => {
        if state.is_six_button {
            // do something special for six-button controllers if you like
        }
        
        if state.is_pressed(MegaDriveButton::Start) {
            // start button is currently held down
        }
    }
    Err(Error:NotPresent) => {} // controller is not connected
    _ => {}
}

Hardware Reference

The Sega Mega Drive uses a standard DB9 serial port connector for controllers.

Controller Connectors

      CONSOLE PORT (MALE)
 ,---------------------------,
 \  (1)  (2)  (3)  (4)  (5)  /
  \   (6)  (7)  (8)  (9)    /
   `-----------------------'

   CONTROLLER CABLE (FEMALE)
 ,---------------------------,
 \  (5)  (4)  (3)  (2)  (1)  /
  \   (9)  (8)  (7)  (6)    /
   `-----------------------'

NOTE: The controller cable uses a female connector, where the console has male connectors.

Pin Mapping

Pin Description Mode
1 Data Bit 0 Input
2 Data Bit 1 Input
3 Data Bit 2 Input
4 Data Bit 3 Input
5 +5V VDC --
6 Data Bit 4 Input
7 Select Output
8 Ground --
9 Data Bit 5 Input

NOTE: The Mode is from the perspective of the console or microcontroller reading the controller.

Credits

Thanks to PlutieDev documentation on how the Mega Drive controller works. Especially useful for polling six-button controllers.

TODO:

  • Library Documentation via mdbook + GitHub Actions
  • Hardware Documentation via mdbook + GitHub Actions
  • Shift Register Support (Parallel-In)
  • Sega Mouse Support
  • Sega Multi-Tap Support
  • Master System Support
  • Unit Tests

Dependencies

~71KB