From 73913a33a2ba31629288b8a11f0e6076aa3b39ef Mon Sep 17 00:00:00 2001
From: flo-x <7840512+flo-x@users.noreply.github.com>
Date: Wed, 24 May 2023 19:22:10 +0100
Subject: [PATCH] [TOUCH] Add a sensor for esp32's touch sensing (#1650)

---
 docs/use/sensors.md   |  15 ++++
 main/ZsensorTouch.ino | 154 ++++++++++++++++++++++++++++++++++++++++++
 main/config_Touch.h   | 101 +++++++++++++++++++++++++++
 main/main.ino         |  10 +++
 4 files changed, 280 insertions(+)
 create mode 100644 main/ZsensorTouch.ino
 create mode 100644 main/config_Touch.h

diff --git a/docs/use/sensors.md b/docs/use/sensors.md
index ca0dac7..6830ebb 100644
--- a/docs/use/sensors.md
+++ b/docs/use/sensors.md
@@ -56,3 +56,18 @@ You will receive every `TimeBetweenPublishingRN8209` (set into config_RN8209.h)
 One reading is done every 0.5s.
 
 `home/OpenMQTTGateway/RN8209toMQTT {"volt":120.345,"current":7.9264,"power":954.6132}`
+
+### Touch
+This sensor is only for ESP32, using the touch sensing peripheral. Up to 10 touch buttons can be defined, linked to 10 ESP32 pins that support touch sensing (GPIOs 0, 2, 4, 12, 13, 14, 15, 27, 32, 33) by defining TOUCH_GPIO, or TOUCH_GPIO_0 through TOUCH_GPIO_9. For example:
+
+`#define TOUCH_GPIO 4`
+
+The default is one sensor on GPIO 4.
+
+When a touch is detected, a message is sent indicating the number of the button ("id"), the fact that a touch button was pressed ("on" is 1) and the value measured by the esp32 ("value").
+
+`home/OpenMQTTGateway/touchToMQTT {"id":0,"on":1,"value":10}`
+
+When the button stops being touched (e.g., the finger is lifted off the button), a message is sent indicating that the button was released ("on" is 0), as well as the duration of the button press in milliseconds ("onDuration").
+
+`home/OpenMQTTGateway/touchToMQTT {"id":0,"on":0,"value":70,"onDuration":320}`
diff --git a/main/ZsensorTouch.ino b/main/ZsensorTouch.ino
new file mode 100644
index 0000000..82d154f
--- /dev/null
+++ b/main/ZsensorTouch.ino
@@ -0,0 +1,154 @@
+/*  
+  OpenMQTTGateway Addon  - ESP8266 or Arduino program for home automation 
+
+   Act as a wifi or ethernet gateway between your 433mhz/infrared IR signal  and a MQTT broker 
+   Send and receiving command by MQTT
+ 
+    For esp32, touch sensor reading add-on.
+  
+    Copyright: (c) Florian Xhumari
+    
+    This file is part of OpenMQTTGateway.
+    
+    OpenMQTTGateway is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenMQTTGateway 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <HardwareSerial.h>
+
+#include "ArduinoJson.h"
+#include "User_config.h"
+#include "config_Touch.h"
+
+#ifdef ZsensorTouch
+
+#  ifndef ESP32
+#    error Only supported on esp32
+#  endif
+
+//Time used to wait for an interval before resending touch sensor value
+static unsigned long touchTimeRead = 0;
+
+// for each touch button
+struct TouchStatus {
+  uint8_t pin;
+  uint16_t timePublished = 0;
+  uint16_t timeStatusChanged = 0;
+  uint16_t avg = 10 * 256; // starting value; multiplied by 256
+  bool isOn = false;
+  bool wasOn = false;
+  int onCount = 0; // number of consecutive readings that were considered "ON"
+  unsigned long onTime; // time the button was turned on
+};
+
+static TouchStatus status[TOUCH_SENSORS];
+
+void setupTouch() {
+#  if TOUCH_SENSORS > 0
+  status[0].pin = TOUCH_GPIO_0;
+#  endif
+#  if TOUCH_SENSORS > 1
+  status[1].pin = TOUCH_GPIO_1;
+#  endif
+#  if TOUCH_SENSORS > 2
+  status[2].pin = TOUCH_GPIO_2;
+#  endif
+#  if TOUCH_SENSORS > 3
+  status[3].pin = TOUCH_GPIO_3;
+#  endif
+#  if TOUCH_SENSORS > 4
+  status[4].pin = TOUCH_GPIO_4;
+#  endif
+#  if TOUCH_SENSORS > 5
+  status[5].pin = TOUCH_GPIO_5;
+#  endif
+#  if TOUCH_SENSORS > 6
+  status[6].pin = TOUCH_GPIO_6;
+#  endif
+#  if TOUCH_SENSORS > 7
+  status[7].pin = TOUCH_GPIO_7;
+#  endif
+#  if TOUCH_SENSORS > 8
+  status[8].pin = TOUCH_GPIO_8;
+#  endif
+#  if TOUCH_SENSORS > 9
+  status[9].pin = TOUCH_GPIO_9;
+#  endif
+  for (int i = 0; i < TOUCH_SENSORS; i++) {
+    Log.notice(F("TOUCH_GPIO_%d: %d" CR), i, status[i].pin);
+  }
+  touchTimeRead = millis() - TOUCH_TIME_BETWEEN_READINGS; // so we get a first reading at the beginning
+}
+
+void MeasureTouch() {
+  unsigned long now = millis();
+  if (now - touchTimeRead < TOUCH_TIME_BETWEEN_READINGS) {
+    return;
+  }
+  touchTimeRead = now;
+  for (int i = 0; i < TOUCH_SENSORS; i++) {
+    TouchStatus* button = &status[i];
+
+    uint16_t val = touchRead(button->pin);
+    if (val == 0) {
+      // just ignore a 0 reading
+      continue;
+    }
+
+    // we'll work in 1/265th of a unit value returned by touchRead(), in order
+    // to have a better precision when performing averages and divisions, while
+    // not using floating point calculations.
+    uint16_t curValue = val * 256;
+    bool isOn = (curValue < button->avg * (TOUCH_THRESHOLD * 256 / 100) / 256); // just so that we divide by 256 and not by 100
+    if (!isOn) {
+      button->avg = (button->avg * 127 + val * 256 * 1) / 128; // exponential averaging, factor = 1/128
+    }
+    int lastOnCount = button->onCount;
+    if (isOn) {
+      ++button->onCount;
+    } else {
+      button->onCount = 0;
+    }
+
+    bool isStatusChanged = false;
+    if (((button->wasOn && !isOn) || (!button->wasOn && isOn && button->onCount >= TOUCH_MIN_DURATION / TOUCH_TIME_BETWEEN_READINGS)) && now - button->timeStatusChanged > TOUCH_DEBOUNCE_TIME) { // debounce
+      isStatusChanged = true;
+      button->wasOn = isOn;
+      button->timeStatusChanged = now;
+      if (isOn) {
+        button->onTime = now;
+      }
+    }
+    // keep timeStatusChanged from getting too old, so not to go
+    // beyond timestamp wrapping
+    if (now - button->timeStatusChanged > 100000) {
+      button->timeStatusChanged = now - 100000;
+    }
+    if (isStatusChanged) {
+      const int JSON_MSG_CALC_BUFFER = JSON_OBJECT_SIZE(4);
+      StaticJsonDocument<JSON_MSG_CALC_BUFFER> jsonDoc;
+      JsonObject touchData = jsonDoc.to<JsonObject>();
+      touchData["id"] = i;
+      touchData["on"] = (isOn ? 1 : 0);
+      touchData["value"] = (int)(curValue / 256);
+      if (!isOn) { // when turning off, send the duration the button was on
+        touchData["onDuration"] = now - button->onTime + TOUCH_MIN_DURATION;
+      }
+      pub(TOUCHTOPIC, touchData);
+      button->timePublished = now;
+    }
+    // adjust measure time so that min(avg of all buttons) is around 60 (between 40 and 80)
+    // TODO
+
+  } // loop
+}
+#endif
diff --git a/main/config_Touch.h b/main/config_Touch.h
new file mode 100644
index 0000000..4a537ad
--- /dev/null
+++ b/main/config_Touch.h
@@ -0,0 +1,101 @@
+/*  
+  OpenMQTTGateway  - ESP8266 or Arduino program for home automation 
+
+   Act as a wifi or ethernet gateway between your 433mhz/infrared IR signal  and a MQTT broker 
+   Send and receiving command by MQTT
+ 
+   This files enables to set your parameter for the esp32's touch buttons
+  
+    Copyright: (c) Florian Xhumari
+    Uses work by Florian ROBERT
+  
+    This file is part of OpenMQTTGateway.
+    
+    OpenMQTTGateway is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenMQTTGateway 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef config_Touch_h
+#define config_Touch_h
+
+extern void setupTouch();
+extern void touchToMQTT();
+/*----------------------------USER PARAMETERS-----------------------------*/
+/*-------------DEFINE YOUR MQTT PARAMETERS BELOW----------------*/
+#define TOUCHTOPIC "/touchToMQTT"
+
+// Time between readings of the touch sensor. Don't make it too short, as
+// reading one touch sensor takes 0.5 ms.
+#if !defined(TOUCH_TIME_BETWEEN_READINGS) || (TOUCH_TIME_BETWEEN_READINGS) < 10
+#  define TOUCH_TIME_BETWEEN_READINGS 30
+#endif
+
+// We take the average reading of the sensor, and consider as "touched" state
+// any reading less than average * TOUCH_THRESHOLD / 100.
+#if !defined(TOUCH_THRESHOLD)
+#  define TOUCH_THRESHOLD 75
+#endif
+
+// Minimum duration of "touched" state to generate a touch event. By default,
+// we'll wait 3 readings indicating "touched" in order to generate a touch event.
+#if !defined(TOUCH_MIN_DURATION) || (TOUCH_MIN_DURATION < 10)
+#  define TOUCH_MIN_DURATION 90
+#endif
+
+// After a touch was sensed, don't consider changes to "touched" status
+// for this duration.
+#if !defined(TOUCH_DEBOUNCE_TIME) || (TOUCH_DEBOUNCE_TIME < 100)
+#  define TOUCH_DEBOUNCE_TIME 200
+#endif
+
+/****************************************
+ *
+ * One can define TOUCH_GPIO, or TOUCH_GPIO_0 through TOUCH_GPIO_9 to
+ * include up to 10 sensors.
+ * 
+ * By default there's only one sensor at TOUCH_GPIO, default to
+ * pin 4 (T0).
+ * 
+ ****************************************/
+
+#if defined(TOUCH_GPIO) && !defined(TOUCH_GPIO_0)
+#  define TOUCH_GPIO_0 (TOUCH_GPIO)
+#endif
+
+#if !defined(TOUCH_GPIO_0)
+// T0 == GPIO 4
+#  define TOUCH_GPIO_0 T0
+#endif
+
+#if defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2) && defined(TOUCH_GPIO_3) && defined(TOUCH_GPIO_4) && defined(TOUCH_GPIO_5) && defined(TOUCH_GPIO_6) && defined(TOUCH_GPIO_7) && defined(TOUCH_GPIO_8) && defined(TOUCH_GPIO_9)
+#  define TOUCH_SENSORS 10
+#elif defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2) && defined(TOUCH_GPIO_3) && defined(TOUCH_GPIO_4) && defined(TOUCH_GPIO_5) && defined(TOUCH_GPIO_6) && defined(TOUCH_GPIO_7) && defined(TOUCH_GPIO_8)
+#  define TOUCH_SENSORS 9
+#elif defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2) && defined(TOUCH_GPIO_3) && defined(TOUCH_GPIO_4) && defined(TOUCH_GPIO_5) && defined(TOUCH_GPIO_6) && defined(TOUCH_GPIO_7)
+#  define TOUCH_SENSORS 8
+#elif defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2) && defined(TOUCH_GPIO_3) && defined(TOUCH_GPIO_4) && defined(TOUCH_GPIO_5) && defined(TOUCH_GPIO_6)
+#  define TOUCH_SENSORS 7
+#elif defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2) && defined(TOUCH_GPIO_3) && defined(TOUCH_GPIO_4) && defined(TOUCH_GPIO_5)
+#  define TOUCH_SENSORS 6
+#elif defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2) && defined(TOUCH_GPIO_3) && defined(TOUCH_GPIO_4)
+#  define TOUCH_SENSORS 5
+#elif defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2) && defined(TOUCH_GPIO_3)
+#  define TOUCH_SENSORS 4
+#elif defined(TOUCH_GPIO_1) && defined(TOUCH_GPIO_2)
+#  define TOUCH_SENSORS 3
+#elif defined(TOUCH_GPIO_1)
+#  define TOUCH_SENSORS 2
+#else
+#  define TOUCH_SENSORS 1
+#endif
+
+#endif
diff --git a/main/main.ino b/main/main.ino
index 3af21d4..0b8056d 100644
--- a/main/main.ino
+++ b/main/main.ino
@@ -168,6 +168,9 @@ struct GfSun2000Data {};
 #ifdef ZsensorGPIOKeyCode
 #  include "config_GPIOKeyCode.h"
 #endif
+#ifdef ZsensorTouch
+#  include "config_Touch.h"
+#endif
 #ifdef ZmqttDiscovery
 #  include "config_mqttDiscovery.h"
 #endif
@@ -1026,6 +1029,10 @@ void setup() {
   setupADC();
   modules.add(ZsensorADC);
 #endif
+#ifdef ZsensorTouch
+  setupTouch();
+  modules.add(ZsensorTouch);
+#endif
 #ifdef ZsensorC37_YL83_HMRD
   setupZsensorC37_YL83_HMRD();
   modules.add(ZsensorC37_YL83_HMRD);
@@ -1744,6 +1751,9 @@ void loop() {
 #ifdef ZsensorADC
       MeasureADC(); //Addon to measure the analog value of analog pin
 #endif
+#ifdef ZsensorTouch
+      MeasureTouch();
+#endif
 #ifdef ZgatewayLORA
       LORAtoMQTT();
 #endif