From 8b7bd918175677002ee232c6bffc4041a7f3e144 Mon Sep 17 00:00:00 2001
From: Amy Gale Ruth Bowersox <amy@erbosoft.com>
Date: Fri, 6 Dec 2019 21:25:15 -0700
Subject: [PATCH] added debounce logic for hardware buttons

---
 src/sysinput.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/sysinput.c b/src/sysinput.c
index bf02ca7..b5688ac 100644
--- a/src/sysinput.c
+++ b/src/sysinput.c
@@ -1,10 +1,14 @@
 #include <stddef.h>
 #include <signal.h>
+#include <string.h>
 #include <pthread.h>
 #include "scode.h"
 #include "log.h"
 #include "msg_queue.h"
 #include "gpio.h"
+#include "time_func.h"
+
+#define DEBOUNCE_BUTTON_MSEC  350
 
 PMSG_QUEUE Sys_Queue = NULL;
 
@@ -16,6 +20,10 @@ static void *input_thread(void *arg)
 {
   UINT32 st, down, up, mask;
   UINT_PTR attr;
+  TIMESTAMP now;
+  TIMESTAMP button_event_ok[GPIO_BUTTON_COUNT];
+
+  memset(button_event_ok, 0, GPIO_BUTTON_COUNT * sizeof(TIMESTAMP));
   
   while (running)
   {
@@ -23,12 +31,18 @@ static void *input_thread(void *arg)
     st = Gpio_read_buttons();
     if (st != last_bstate)
     {
+      now = Time_since_start();
       up = last_bstate & ~st;
       down = st & ~last_bstate;
       for (attr = 1, mask = GRB_STATE_BUTTON1; attr <= GPIO_BUTTON_COUNT; attr++, mask <<= 1)
       {
+	if (now < button_event_ok[attr - 1])
+	  continue;
 	if (up & mask)
+	{
+	  button_event_ok[attr - 1] = now + DEBOUNCE_BUTTON_MSEC;
 	  Mq_post1(Sys_Queue, 0, WM_HWBUTTONUP, attr);
+	}
 	else if (down & mask)
 	  Mq_post1(Sys_Queue, 0, WM_HWBUTTONDOWN, attr);
       }