From 4dd8599ab3c2ff211538c472ae4d944af4e09192 Mon Sep 17 00:00:00 2001
From: Fisch <interfisch@gmx.net>
Date: Thu, 13 Oct 2022 22:47:40 +0200
Subject: [PATCH] improve touch filtering

---
 touchcontroller/src/main.cpp | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/touchcontroller/src/main.cpp b/touchcontroller/src/main.cpp
index 33d13b7..a23284c 100644
--- a/touchcontroller/src/main.cpp
+++ b/touchcontroller/src/main.cpp
@@ -7,11 +7,14 @@ uint16_t rawIn[INPUTS];
 uint16_t countedLow[INPUTS]; //count the times input was below threshold (touched)
 #define TOUCHTHRESHOLD 1000 //below which value input counts as touched. 0<x<1024
 #define COUNTEDLOWTHRESHOLD 10 //how many times input has to be sampled as low in a row to count as real touch. 
+#define COUNTEDLOWTHRESHOLD_OFF 0
 // Inputdelay is given by: COUNTEDLOWTHRESHOLD*ADCREADINTERVAL
 
 unsigned long last_adcmicros=0;
 #define ADCREADINTERVAL 2000 //in microseconds. interval to read all adc values
 
+boolean last_output[INPUTS];
+
 unsigned long last_send=0;
 #define MINIMUMSENDDELAY 10 //in milliseconds. minimum delay between serial sends
 
@@ -62,7 +65,9 @@ void loop() {
           countedLow[i]=COUNTEDLOWTHRESHOLD; //upper limit. prevent overflow
         }
       }else{ //released or not pressed hard enough
-        countedLow[i]=0; //reset counter
+        if (countedLow[i]>0) {
+          countedLow[i]--; //decrease counter
+        }
       }
     }
 
@@ -70,10 +75,19 @@ void loop() {
     
   }
 
+
+  for (uint8_t i=0;i<INPUTS;i++){ //for all keys
+    if (countedLow[i]>=COUNTEDLOWTHRESHOLD) { //key pressed/touched
+      last_output[i]=true;
+    }else if (countedLow[i]<=COUNTEDLOWTHRESHOLD_OFF) { //key pressed/touched
+      last_output[i]=false;
+    }
+  }
+
   // ## Calculate Byte ##
   byte newTouch=0;
   for (uint8_t i=0;i<INPUTS;i++){ //for all keys
-    if (countedLow[i]>=COUNTEDLOWTHRESHOLD) { //key pressed/touched
+    if (last_output[i]) { //key pressed/touched
       newTouch^=1<<i;
     }
   }