From ce9a52271ea769884fc76bdf4e2b2bdc59e592a3 Mon Sep 17 00:00:00 2001
From: Jim Parziale <j.parziale@outlook.com>
Date: Fri, 1 Apr 2022 06:18:20 -0400
Subject: [PATCH] Add example of mulit-ISR

---
 examples/buttons3.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 125 insertions(+)
 create mode 100644 examples/buttons3.c

diff --git a/examples/buttons3.c b/examples/buttons3.c
new file mode 100644
index 0000000..a53c083
--- /dev/null
+++ b/examples/buttons3.c
@@ -0,0 +1,125 @@
+/*
+ * buttons3.c:
+ *	Multiple button handling using wiringPiISRmulti.
+ *
+ ***********************************************************************
+ * This file is part of wiringPi:
+ *      https://github.com/nuncio-bitis/WiringPi
+ *
+ *    wiringPi is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Lesser General Public License as published
+ *by the Free Software Foundation, either version 3 of the License, or (at your
+ *option) any later version.
+ *
+ *    wiringPi is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Lesser General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Lesser General Public License
+ *    along with wiringPi.  If not, see <http://www.gnu.org/licenses/>.
+ ***********************************************************************
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+#include <wiringPi.h>
+
+//**********************************************************************************************************************
+
+// GPIOs (BCM) that buttons are attached to:
+static const int buttons[] = { 26, 16, 20, 21 };
+static const int nButtons = (sizeof (buttons) / sizeof (int));
+
+static int terminate_process = 0;
+
+//**********************************************************************************************************************
+
+/**
+ * Intercepts and handles signals from QNX
+ * This function is called when the SIGTERM signal is raised by QNX
+ */
+static void Signal_handler(int sig)
+{
+  printf("Received signal %d\n", sig);
+
+  // Signal process to exit.
+  terminate_process = 1;
+}
+
+//**********************************************************************************************************************
+
+static int getButtonIndex (int pin)
+{
+    for (int i = 0; i < nButtons; ++i)
+    {
+        if (buttons[i] == pin)
+        {
+            return i;
+        }
+    }
+    return -1;
+}
+
+//**********************************************************************************************************************
+
+static int nInts = 0;
+
+static void Button_Wait (int pin)
+{
+  nInts++;
+  printf ("%s: Interrupt on pin %d; Button #%d; nInts=%d\n", __FUNCTION__, pin, 1+getButtonIndex(pin), nInts);
+}
+
+//**********************************************************************************************************************
+
+int main (int argc, char *argv[])
+{
+    // Set the handler for SIGTERM (15)
+    signal(SIGTERM, Signal_handler);
+    signal(SIGHUP,  Signal_handler);
+    signal(SIGINT,  Signal_handler);
+    signal(SIGQUIT, Signal_handler);
+    signal(SIGTRAP, Signal_handler);
+    signal(SIGABRT, Signal_handler);
+    signal(SIGALRM, Signal_handler);
+    signal(SIGUSR1, Signal_handler);
+    signal(SIGUSR2, Signal_handler);
+
+    printf ("Raspberry Pi Button Test\n");
+
+    // ----------------------------------------------------
+
+    wiringPiSetupGpio ();
+
+    // Setup the inputs
+    for (int i = 0; i < nButtons; ++i)
+    {
+        pinMode (buttons[i], INPUT);
+        pullUpDnControl (buttons[i], PUD_UP);
+    }
+
+    // ----------------------------------------------------
+
+    // Set up a callback for when any of these buttons is pressed/released
+    // Note: there is no debounce proterction here.
+    // You may see multiple interrupts with one button.
+    if (wiringPiISRmulti ((int *)buttons, nButtons, INT_EDGE_RISING, &Button_Wait) < 0)
+    {
+        fprintf (stderr, "%s: Unable to setup ISR: %s\n", argv[0], strerror(errno));
+        return EXIT_FAILURE;
+    }
+
+    nInts = 0;
+    while (!terminate_process)
+    {
+        delayMs(100);
+    }
+
+    return EXIT_SUCCESS;
+}
+
+//**********************************************************************************************************************