From: Keith Packard <keithp@keithp.com>
Date: Sun, 13 Nov 2011 02:30:56 +0000 (-0800)
Subject: altos: debounce buttons
X-Git-Tag: 1.0.9.4~83
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=4de8bf6da4d725bb0514d032b0708c5cf420e8fa

altos: debounce buttons

Provide API to clear out any button events that happen during startup,
and then discard button events 'too close' together.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/cc1111/ao_arch.h b/src/cc1111/ao_arch.h
index 001165fa..eb8ce9be 100644
--- a/src/cc1111/ao_arch.h
+++ b/src/cc1111/ao_arch.h
@@ -231,6 +231,9 @@ ao_button_init(void);
 char
 ao_button_get(void) __critical;
 
+void
+ao_button_clear(void) __critical;
+
 /* ao_string.c */
 
 void
diff --git a/src/cc1111/ao_button.c b/src/cc1111/ao_button.c
index 77a8dde8..69f3475f 100644
--- a/src/cc1111/ao_button.c
+++ b/src/cc1111/ao_button.c
@@ -36,11 +36,17 @@ static __code struct {
 
 #define NUM_BUTTONS	((sizeof ao_buttons) / sizeof (ao_buttons[0]))
 
+static __xdata uint16_t ao_button_tick[NUM_BUTTONS];
+
 static void
 ao_button_insert(char n)
 {
-	ao_fifo_insert(ao_button_fifo, n);
-	ao_wakeup(&ao_button_fifo);
+	uint16_t	now = ao_time();
+	if ((now - ao_button_tick[n]) > 20) {
+		ao_button_tick[n] = now;
+		ao_fifo_insert(ao_button_fifo, n);
+		ao_wakeup(&ao_button_fifo);
+	}
 }
 
 static void
@@ -77,6 +83,15 @@ ao_button_get(void) __critical
 	return b;
 }
 
+void
+ao_button_clear(void) __critical
+{
+	char b;
+
+	while (!ao_fifo_empty(ao_button_fifo))
+		ao_fifo_remove(ao_button_fifo, b);
+}
+
 void
 ao_p0_isr(void) ao_arch_interrupt(13)
 {