Three-state machine for button

- press and hold: send "r" key (for rewind function of RetroArch)
- press and release three times: send "ESC"
- press and release five times: shutdown

include/button.h

@@ -0,0 +1,47 @@
+/*
+ * SNESDev - Simulates a virtual keyboard for two SNES controllers that are 
+ * connected to the GPIO pins of the Raspberry Pi.
+ *
+ * (c) Copyright 2012  Florian Müller (petrockblog@flo-mueller.com)
+ *
+ * SNESDev homepage: https://github.com/petrockblog/SNESDev-RPi
+ *
+ * Permission to use, copy, modify and distribute SNESDev in both binary and
+ * source form, for non-commercial purposes, is hereby granted without fee,
+ * providing that this license information and copyright notice appear with
+ * all copies and any derived work.
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event shall the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * SNESDev is freeware for PERSONAL USE only. Commercial users should
+ * seek permission of the copyright holders first. Commercial use includes
+ * charging money for SNESDev or software derived from SNESDev.
+ *
+ * The copyright holders request that bug fixes and improvements to the code
+ * should be forwarded to them so everyone can benefit from the modifications
+ * in future versions.
+ *
+ * Raspberry Pi is a trademark of the Raspberry Pi Foundation.
+ */
+
+#ifndef button_h
+#define button_h
+
+#include <inttypes.h>
+#include <bcm2835.h>
+#include <unistd.h>
+#include <stdio.h>
+
+/* holds the GPIO pins for the clock, strobe and data signals */
+typedef struct {
+    int
+} button;
+
+
+/* check the state of each button of each controller */
+void updateButton();
+
+#endif
+

src/main.c

@@ -42,15 +42,20 @@
 
 /* time to wait after each cycle */
 #define FRAMEWAIT 20
-#define FRAMEWAITLONG 200
+#define FRAMEWAITLONG 100
 
 /* set the GPIO pins of the button and the LEDs. */
 #define BUTTONPIN  RPI_GPIO_P1_11
+#define BTNSTATE_IDLE 0
+#define BTNSTATE_PRESS 1
+#define BTNSTATE_RELEASE 2
+
 
 int uinp_fd;
 int doRun, pollButton, pollPads;
-time_t timePressed;
-uint8_t lastBtnState;
+time_t btnLastTime;
+uint8_t btnState;
+uint8_t btnPressCtr;
 
 /* Signal callback function */
 void sig_handler(int signo) {
@@ -128,30 +133,59 @@ void checkButton(int uinh) {
   	// read the state of the button into a local variable
 	uint8_t buttonState = bcm2835_gpio_lev(BUTTONPIN);
 
-	if (buttonState==HIGH && lastBtnState==LOW) {
-		timePressed=time(NULL);
-	} else if (buttonState==LOW && lastBtnState==HIGH) {
-		time_t curTime = time(NULL);
-		double dif = difftime(curTime,timePressed);
-		if ( dif>=3 ) {
-			// send F4 (quit Emulation Station) and shut down
-			pollButton = 0;
-  			pollPads = 0;
-			send_key_event(uinh, KEY_F4,1);
-			usleep(50000);
-			send_key_event(uinh, KEY_F4,0);
-
-			system("shutdown -t 3 -h now");
-		} else {
-			// Sending ESC
-			send_key_event(uinh, KEY_ESC,1);
-			usleep(50000);
-			send_key_event(uinh, KEY_ESC,0);
-		}
-
+  	// three-state machine:
+  	// - press and hold: send "r" key (for rewind function of RetroArch)
+  	// - press and release three times: send "ESC"
+  	// - press and release five times: shutdown
+	switch ( btnState ) {
+		case BTNSTATE_IDLE:
+			if (buttonState==HIGH ) {
+				btnLastTime=time(NULL);
+				btnState = BTNSTATE_PRESS;
+				btnPressCtr += 1;
+			}
+			break;
+		case BTNSTATE_PRESS:
+			if (buttonState==LOW ) {
+				btnLastTime=time(NULL);
+				btnState = BTNSTATE_RELEASE;
+			} else if (buttonState==HIGH && btnPressCtr==1 && difftime(time(NULL),btnLastTime)>1) {
+				send_key_event(uinh, KEY_R,1);
+			}
+			break;
+		case BTNSTATE_RELEASE:
+		 	if (buttonState==LOW && difftime(time(NULL),btnLastTime)>1 ) {
+
+			 	if (btnPressCtr==1) {
+					send_key_event(uinh, KEY_R,0);
+			 	} else if (btnPressCtr==3) {
+					// Sending ESC
+					printf("Sending ESC.\n");
+					send_key_event(uinh, KEY_ESC,1);
+					usleep(50000);
+					send_key_event(uinh, KEY_ESC,0);
+				} else if ( btnPressCtr==5 ) {
+					printf("Shutting down.\n");
+					pollButton = 0;
+			 		pollPads = 0;
+					send_key_event(uinh, KEY_F4,1);
+					usleep(50000);
+					send_key_event(uinh, KEY_F4,0);
+
+					system("shutdown -t 3 -h now");
+				}
+
+				btnLastTime=time(NULL);
+				btnState = BTNSTATE_IDLE;
+				btnPressCtr = 0;
+			} else if (buttonState==HIGH  ) {
+				btnLastTime=time(NULL);
+				btnState = BTNSTATE_PRESS;
+				btnPressCtr += 1;
+			}
+			break;
 	}
-	lastBtnState=buttonState;
-
+	// printf("State: %d, ctr: %d\n",btnState,btnPressCtr );
 }
 
 /* checks, if a button on the pad is pressed and sends an event according the button state. */
@@ -172,6 +206,9 @@ int main(int argc, char *argv[]) {
 	pollPads = 1;
 	doRun = 1;
 
+	btnState = BTNSTATE_IDLE;
+	btnPressCtr = 0;
+
 	// check command line arguments
 	if (argc > 1) {
 		// argv[1]==1 poll controllers only