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mirror of https://github.com/mcgurk/Arduino-USB-HID-RetroJoystickAdapter synced 2024-12-22 07:28:53 -05:00
Arduino-USB-HID-RetroJoysti.../Tutorial/SimpleAtariExample.ino
2016-09-06 10:09:45 +03:00

124 lines
2.8 KiB
C++

/*
* Simple Atari joystick adapter (joystick HID) for learning purposes
* McGurk 6.9.2016
*/
#include "Joystick2.h"
// Here we define Arduino pins we use. Along with these we have to connect joystick ground to Arduino GND.
// Because of Arduino internal pullup resistor off state is 1. Moving joystick switches corresponding pin to ground and then it is 0.
#define UP 2 // 9-pin D-connector pin 1
#define DOWN 3 // 9-pin D-connector pin 2
#define LEFT 4 // 9-pin D-connector pin 3
#define RIGHT 5 // 9-pin D-connector pin 4
#define BUTTON 6 // 9-pin D-connector pin 6
// 9-pin D-connector pin 8 to GND
// We keep record how everything was last time, so we can compare if anything have changed. (1 = off, 0 = on)
byte lastUP = 1;
byte lastDOWN = 1;
byte lastLEFT = 1;
byte lastRIGHT = 1;
byte lastBUTTON = 1;
byte newUP = 1;
byte newDOWN = 1;
byte newLEFT = 1;
byte newRIGHT = 1;
byte newBUTTON = 1;
void setup() {
pinMode(UP, INPUT_PULLUP);
pinMode(DOWN, INPUT_PULLUP);
pinMode(LEFT, INPUT_PULLUP);
pinMode(RIGHT, INPUT_PULLUP);
pinMode(BUTTON, INPUT_PULLUP);
Joystick[0].begin(false);
}
// We use this flag to indicate if anything changes.
byte flag = 0;
void loop()
{
// Read joystick state (1 = off, 0 = on).
newUP = digitalRead(UP);
newDOWN = digitalRead(DOWN);
newLEFT = digitalRead(LEFT);
newRIGHT = digitalRead(RIGHT);
newBUTTON = digitalRead(BUTTON);
// Check if anything changed. This way we don't have to send anything to USB if nothing happened after last time.
if (newUP != lastUP) {
lastUP = newUP;
flag = 1;
}
if (newDOWN != lastDOWN) {
lastDOWN = newDOWN;
flag = 1;
}
if (newLEFT != lastLEFT) {
lastLEFT = newLEFT;
flag = 1;
}
if (newRIGHT != lastRIGHT) {
lastRIGHT = newRIGHT;
flag = 1;
}
if (newBUTTON != lastBUTTON) {
lastBUTTON = newBUTTON;
flag = 1;
}
// If anythings changed, build and send new state.
if (flag) {
// Clear directions and buttons before start building new state.
Joystick[0].setYAxis(0);
Joystick[0].setXAxis(0);
Joystick[0].setButton(0, 0);
// Build new state according what we read earlier.
// We need exclamation mark in these if-conditions, because swithes are active low (0 = on, 1 = off).
if (!newUP) {
Joystick[0].setYAxis(-127); //UP
}
if (!newDOWN) {
Joystick[0].setYAxis(127); //DOWN
}
if (!newLEFT) {
Joystick[0].setXAxis(-127); //LEFT
}
if (!newRIGHT) {
Joystick[0].setXAxis(127); //RIGHT
}
if (!newBUTTON) {
Joystick[0].setButton(0, 1); //BUTTON
}
// Everything is ready. Send state. Before this point, we haven't send any joystick directions to USB.
Joystick[0].sendState();
// Remember to clear flag.
flag = 0;
}
// Little 1ms breathing break.
delayMicroseconds(1000);
}