SNES multiplayer interface tested and also working great

tests realized with killer instinct on ZSNES (and also Project64, both killers instincts hehe), working great, the same way than with N64 controller: simplest(naïve) implementation

example added, soon on wiki too (N64 is already available!)

examples/SNES_usb_multiplayer/SNES_usb_multiplayer.ino

@@ -0,0 +1,20 @@
+#include "SNES_gamepad_usb.h"
+#include "multiplayer.h"
+
+const uint8_t CLOCK_PIN = 9;
+const uint8_t LATCH_PIN = 8;
+const uint8_t DATA_PIN1 = 7;
+const uint8_t DATA_PIN2 = 6;
+// any digital pin will work for this SNES gamepad interface
+// tested so far up to 4 gamepads simultaneously
+
+SNES_hid p1(1, DATA_PIN1, CLOCK_PIN, LATCH_PIN);
+SNES_hid p2(2, DATA_PIN2, CLOCK_PIN, LATCH_PIN);
+
+gamepad::multiplayer<SNES_hid> multi(p1,p2);
+
+void setup() {}
+
+void loop() {
+  multi.read();
+}