From 83afcad3c4daaf4e9ec0385cd5a3f207129450a7 Mon Sep 17 00:00:00 2001
From: David Mueller <mueller_david@hotmail.com>
Date: Wed, 27 Nov 2024 09:56:36 +0100
Subject: [PATCH] toggle2nist: Fix issues with race conditions and add input
 button debounce

---
 src/hal/components/toggle2nist.comp | 69 ++++++++++++++++-------------
 1 file changed, 38 insertions(+), 31 deletions(-)

diff --git a/src/hal/components/toggle2nist.comp b/src/hal/components/toggle2nist.comp
index 427948f298a..74f5cf5be8d 100644
--- a/src/hal/components/toggle2nist.comp
+++ b/src/hal/components/toggle2nist.comp
@@ -4,28 +4,29 @@ description
 """
 Toggle2nist can be used with a momentary push button 
 to control a device that has separate on and off inputs
-and an is-on output. 
+and an is-on output.
+A debounce delay in cycles can be set. (default = 2)
 
 \[bu] On a rising edge on pin \\fIin\\fR when \\fIis-on\\fR is low: It sets \\fIon\\fR until \\fIis-on\\fR becomes high.
 
 \[bu] On a rising edge on pin \\fIin\\fR when \\fIis-on\\fR is high: It sets \\fIoff\\fR until \\fIis-on\\fR becomes low.
 
 
-       ┐     ┌─────xxxxxxxxxxxx┐           ┌─────xxxxxxxxxxxx┐
+       ┐     ┌─────xxxxxxxxxxxx┐           ┌─────xxxxxxxxxxxx┐
 .br
-in   : └─────┘     xxxxxxxxxxxx└───────────┘     xxxxxxxxxxxx└─────
+in   : └─────┘     xxxxxxxxxxxx└───────────┘     xxxxxxxxxxxx└─────
 .br
-       ┐     ┌───────────┐
+       ┐     ┌───────────┐
 .br
-on   : └─────┘           └─────────────────────────────────────────
+on   : └─────┘           └─────────────────────────────────────────
 .br
-       ┐                                   ┌───────────┐
+       ┐                                   ┌───────────┐
 .br
-off  : └───────────────────────────────────┘           └───────────
+off  : └───────────────────────────────────┘           └───────────
 .br
-       ┐                 ┌─────────────────────────────┐
+       ┐                 ┌─────────────────────────────┐
 .br
-is-on: └─────────────────┘                             └───────────
+is-on: └─────────────────┘                             └───────────
 
 """;
 
@@ -33,32 +34,38 @@ pin in  bit in;
 pin in  bit is_on;
 pin out bit on;
 pin out bit off;
-variable int old_in;
-variable int to_state=0;
+param rw u32 debounce = 2 "debounce delay in cycles";
+variable int debounce_cntr;
+variable int state;
+
 function _ nofp;
 license "GPL";
-author "Anders Wallin";
+author "David Mueller, Based on work by Anders Wallin and John Kasunich";
 ;;
 FUNCTION(_)  {
-if (in!=old_in) /* a toggle has occurred */ {
-    if (is_on) {   /* turn OFF if it's on */
-        on=0;
-        off=1;
-        to_state=0;
-    }
-    else if (!is_on) { /* turn ON if it's off */
-        on=1;
-        off=0;
-        to_state=1;
+
+    if (( debounce < 1 ) || ( debounce > 10000 )) {
+	debounce = 2; 	/* set a sane value */
     }
-}
-else {
-/* reset pins when we see the desired state */
-    if (to_state==is_on) {
-        on=0;
-        off=0;
+
+    if (in && state == 0 )  { /* input has changed from debounced 0 -> 1 */
+	    debounce_cntr++;
+	    if ( debounce_cntr >= debounce ) {
+            if (!is_on) { /* turn ON if it's off */
+                on=1;
+                off=0;
+            } else { /* turn OFF if it's on */
+                on=0;
+                off=1;
+            }
+            state = 1;
+            debounce_cntr = 0;
+	    }
+    } else if (!in && state == 1) { /* input has changed from debounced 1 -> 0 */
+	    debounce_cntr++;
+	    if ( debounce_cntr >= debounce ) {
+            state = 0;
+            debounce_cntr = 0;
+        }
     }
 }
-old_in=in;
-}
-