Touch Sensor IDF Refactoring (#6194)

Summary

Touch Sensor refactoring to be based on IDF 4.4.
Adds support to ESP32S2 and future ESP32S3.

Adds some new APIs:

For all chips:

void touchAttachInterruptArg(uint8_t pin, void (*userFunc)(void*), void *arg, uint32_t threshold);
This function allows the user to add and pass a void* parameter to the ISR user callback.

void touchDetachInterrupt(uint8_t pin);
This function detaches ISR call back for the touch pad pin.

Only ESP32 chip

void touchInterruptSetThresholdDirection(bool mustbeLower);
This function allows the user to set if the ISR callback will be activated when the touch sensor readings are lower or higher than the threshold defined. See example TouchButton.ino.

Only ESP32-S2 and ESP32-S3 chips

bool touchInterruptGetLastStatus(uint8_t pin);
This function reports if the touch pad pin is touched or untouched. It can be used with ISR to identify when it is touched and untouched (released). See example TouchButtonV2.ino.

Impact

None. ll original APIs and examples now run on ESP32 and ESP32-S2.

Related links

Fix #6095
Fix #6034
Fix #5799
Fix #5745
Fix #5527
Fix #5493
Fix #4321
Fix #4044
Fix #2722
Fix #2625

cores/esp32/esp32-hal-touch.c

@@ -12,219 +12,251 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "esp32-hal-touch.h"
-#ifndef CONFIG_IDF_TARGET_ESP32C3
-#include "freertos/FreeRTOS.h"
-#include "freertos/task.h"
-#include "esp_attr.h"
-#include "soc/rtc_io_reg.h"
-#include "soc/sens_reg.h"
-#include "soc/sens_struct.h"
-#include "soc/rtc_cntl_reg.h"
+#include "soc/soc_caps.h"
+#if SOC_TOUCH_SENSOR_NUM > 0
+
 #include "driver/touch_sensor.h"
+#include "esp32-hal-touch.h"
 
-#include "esp_system.h"
-#ifdef ESP_IDF_VERSION_MAJOR // IDF 4+
-#if CONFIG_IDF_TARGET_ESP32 // ESP32/PICO-D4
-#include "esp32/rom/ets_sys.h"
-#include "esp_intr_alloc.h"
-#elif CONFIG_IDF_TARGET_ESP32S2
-#include "esp32s2/rom/ets_sys.h"
-#include "esp_intr_alloc.h"
-#include "soc/periph_defs.h"
-#else 
-#error Target CONFIG_IDF_TARGET is not supported
-#endif
-#else // ESP32 Before IDF 4.0
-#include "rom/ets_sys.h"
-#include "esp_intr.h"
-#endif
+/*
+    Internal Private Touch Data Structure and Functions
+*/
 
+#if SOC_TOUCH_VERSION_1         // ESP32 
 static uint16_t __touchSleepCycles = 0x1000;
 static uint16_t __touchMeasureCycles = 0x1000;
+#elif SOC_TOUCH_VERSION_2       // ESP32S2, ESP32S3
+static uint16_t __touchSleepCycles = TOUCH_PAD_SLEEP_CYCLE_DEFAULT;
+static uint16_t __touchMeasureCycles = TOUCH_PAD_MEASURE_CYCLE_DEFAULT;
+#endif
 
 typedef void (*voidFuncPtr)(void);
-static voidFuncPtr __touchInterruptHandlers[10] = {0,};
-static intr_handle_t touch_intr_handle = NULL;
+typedef void (*voidArgFuncPtr)(void *);
+
+typedef struct {
+    voidFuncPtr fn;
+    bool callWithArgs;
+    void* arg;
+#if SOC_TOUCH_VERSION_2     // Only for ESP32S2 and ESP32S3
+    bool lastStatusIsPressed;
+#endif
+} TouchInterruptHandle_t;
+
+static TouchInterruptHandle_t __touchInterruptHandlers[SOC_TOUCH_SENSOR_NUM] = {0,};
 
-void ARDUINO_ISR_ATTR __touchISR(void * arg)
+static void ARDUINO_ISR_ATTR __touchISR(void * arg)
 {
-#if CONFIG_IDF_TARGET_ESP32
-    uint32_t pad_intr = READ_PERI_REG(SENS_SAR_TOUCH_CTRL2_REG) & 0x3ff;
-    uint32_t rtc_intr = READ_PERI_REG(RTC_CNTL_INT_ST_REG);
-    uint8_t i = 0;
+#if SOC_TOUCH_VERSION_1         // ESP32 
+    uint32_t pad_intr = touch_pad_get_status();
     //clear interrupt
-    WRITE_PERI_REG(RTC_CNTL_INT_CLR_REG, rtc_intr);
-    SET_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL2_REG, SENS_TOUCH_MEAS_EN_CLR);
-
-    if (rtc_intr & RTC_CNTL_TOUCH_INT_ST) {
-        for (i = 0; i < 10; ++i) {
-            if ((pad_intr >> i) & 0x01) {
-                if(__touchInterruptHandlers[i]){
-                    __touchInterruptHandlers[i]();
+    touch_pad_clear_status();
+    // call Pad ISR User callback
+    for (int i = 0; i < SOC_TOUCH_SENSOR_NUM; i++) {
+        if ((pad_intr >> i) & 0x01) {
+            if(__touchInterruptHandlers[i].fn){
+                // keeping backward compatibility with "void cb(void)" and with new "void cb(vooid *)"
+                if (__touchInterruptHandlers[i].callWithArgs) {
+                    ((voidArgFuncPtr)__touchInterruptHandlers[i].fn)(__touchInterruptHandlers[i].arg);
+                } else {
+                    __touchInterruptHandlers[i].fn();
                 }
             }
         }
     }
+#elif SOC_TOUCH_VERSION_2     // ESP32S2, ESP32S3
+    touch_pad_intr_mask_t evt = touch_pad_read_intr_status_mask();
+    uint8_t pad_num = touch_pad_get_current_meas_channel();
+    if (evt & TOUCH_PAD_INTR_MASK_ACTIVE) {
+        // touch has been pressed / touched
+        __touchInterruptHandlers[pad_num].lastStatusIsPressed = true;
+    }
+    if (evt & TOUCH_PAD_INTR_MASK_INACTIVE) {
+        // touch has been released / untouched
+        __touchInterruptHandlers[pad_num].lastStatusIsPressed = false;
+    }
+    if(__touchInterruptHandlers[pad_num].fn){
+        // keeping backward compatibility with "void cb(void)" and with new "void cb(vooid *)"
+        if (__touchInterruptHandlers[pad_num].callWithArgs) {
+            ((voidArgFuncPtr)__touchInterruptHandlers[pad_num].fn)(__touchInterruptHandlers[pad_num].arg);
+        } else {
+            __touchInterruptHandlers[pad_num].fn();
+        }
+    }
 #endif
 }
 
-void __touchSetCycles(uint16_t measure, uint16_t sleep)
+
+
+static void __touchSetCycles(uint16_t measure, uint16_t sleep)
 {
     __touchSleepCycles = sleep;
     __touchMeasureCycles = measure;
-#if CONFIG_IDF_TARGET_ESP32
-    //Touch pad SleepCycle Time
-    SET_PERI_REG_BITS(SENS_SAR_TOUCH_CTRL2_REG, SENS_TOUCH_SLEEP_CYCLES, __touchSleepCycles, SENS_TOUCH_SLEEP_CYCLES_S);
-    //Touch Pad Measure Time
-    SET_PERI_REG_BITS(SENS_SAR_TOUCH_CTRL1_REG, SENS_TOUCH_MEAS_DELAY, __touchMeasureCycles, SENS_TOUCH_MEAS_DELAY_S);
-#else
     touch_pad_set_meas_time(sleep, measure);
-#endif
 }
 
-void __touchInit()
+
+
+static void __touchInit()
 {
     static bool initialized = false;
     if(initialized){
         return;
     }
-    initialized = true;
-#if CONFIG_IDF_TARGET_ESP32
-    SET_PERI_REG_BITS(RTC_IO_TOUCH_CFG_REG, RTC_IO_TOUCH_XPD_BIAS, 1, RTC_IO_TOUCH_XPD_BIAS_S);
-    SET_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL2_REG, SENS_TOUCH_MEAS_EN_CLR);
-    //clear touch enable
-    WRITE_PERI_REG(SENS_SAR_TOUCH_ENABLE_REG, 0x0);
-    SET_PERI_REG_MASK(RTC_CNTL_STATE0_REG, RTC_CNTL_TOUCH_SLP_TIMER_EN);
-    __touchSetCycles(__touchMeasureCycles, __touchSleepCycles);
-    esp_intr_alloc(ETS_RTC_CORE_INTR_SOURCE, (int)ARDUINO_ISR_FLAG, __touchISR, NULL, &touch_intr_handle);
-#else
-    touch_pad_init();
-    touch_pad_set_voltage(TOUCH_HVOLT_2V7, TOUCH_LVOLT_0V5, TOUCH_HVOLT_ATTEN_0V5);
-    touch_pad_set_idle_channel_connect(TOUCH_PAD_CONN_GND);
-    __touchSetCycles(__touchMeasureCycles, __touchSleepCycles);
+ 
+   esp_err_t err = ESP_OK;
+
+#if SOC_TOUCH_VERSION_1                         // ESP32
+    err = touch_pad_init();
+    if (err != ESP_OK) {
+        goto err;
+    }
+    // the next two lines will drive the touch reading values -- both will return ESP_OK
+    touch_pad_set_voltage(TOUCH_HVOLT_2V7, TOUCH_LVOLT_0V5, TOUCH_HVOLT_ATTEN_0V); 
+    touch_pad_set_meas_time(__touchMeasureCycles, __touchSleepCycles);
+    // Touch Sensor Timer initiated
+    touch_pad_set_fsm_mode(TOUCH_FSM_MODE_TIMER);   // returns ESP_OK
+    err = touch_pad_filter_start(10);
+    if (err != ESP_OK) {
+        goto err;
+    }
+    // Initial no Threshold and setup
+    for (int i = 0; i < SOC_TOUCH_SENSOR_NUM; i++) {
+        __touchInterruptHandlers[i].fn =  NULL;
+        touch_pad_config(i, SOC_TOUCH_PAD_THRESHOLD_MAX);  // returns ESP_OK
+    }
+    // keep ISR activated - it can run all together (ISR + touchRead())
+    err = touch_pad_isr_register(__touchISR, NULL);
+    if (err != ESP_OK) {
+        goto err;
+    }
+    touch_pad_intr_enable();  // returns ESP_OK
+#elif SOC_TOUCH_VERSION_2                         // ESP32S2, ESP32S3
+    err = touch_pad_init();
+    if (err != ESP_OK) {
+        goto err;
+    }
+    // the next lines will drive the touch reading values -- all os them return ESP_OK
+    touch_pad_set_meas_time(__touchSleepCycles, __touchMeasureCycles);
+    touch_pad_set_voltage(TOUCH_PAD_HIGH_VOLTAGE_THRESHOLD, TOUCH_PAD_LOW_VOLTAGE_THRESHOLD, TOUCH_PAD_ATTEN_VOLTAGE_THRESHOLD);
+    touch_pad_set_idle_channel_connect(TOUCH_PAD_IDLE_CH_CONNECT_DEFAULT);
     touch_pad_denoise_t denoise = {
         .grade = TOUCH_PAD_DENOISE_BIT4,
         .cap_level = TOUCH_PAD_DENOISE_CAP_L4,
     };
     touch_pad_denoise_set_config(&denoise);
     touch_pad_denoise_enable();
-    touch_pad_set_fsm_mode(TOUCH_FSM_MODE_TIMER);
-    touch_pad_fsm_start();
+    // Touch Sensor Timer initiated
+    touch_pad_set_fsm_mode(TOUCH_FSM_MODE_TIMER);  // returns ESP_OK
+    touch_pad_fsm_start();                         // returns ESP_OK
+
+    // Initial no Threshold and setup - TOUCH0 is internal denoise channel
+    for (int i = 1; i < SOC_TOUCH_SENSOR_NUM; i++) {
+        __touchInterruptHandlers[i].fn =  NULL;
+        touch_pad_config(i);                       // returns ESP_OK
+    }
+    // keep ISR activated - it can run all together (ISR + touchRead())
+    err = touch_pad_isr_register(__touchISR, NULL, TOUCH_PAD_INTR_MASK_ACTIVE | TOUCH_PAD_INTR_MASK_INACTIVE);
+     if (err != ESP_OK) {
+        goto err;
+    }
+    touch_pad_intr_enable(TOUCH_PAD_INTR_MASK_ACTIVE | TOUCH_PAD_INTR_MASK_INACTIVE); // returns ESP_OK
 #endif
+
+    initialized = true;
+    return;
+err:
+    log_e(" Touch sensor initialization error.");
+    initialized = false;
+    return;
 }
 
-uint16_t __touchRead(uint8_t pin)
+static touch_value_t __touchRead(uint8_t pin)
 {
     int8_t pad = digitalPinToTouchChannel(pin);
     if(pad < 0){
         return 0;
     }
+    __touchInit();
 
-    pinMode(pin, ANALOG);
+    touch_value_t touch_value;
+    touch_pad_read_raw_data(pad, &touch_value);
 
-    __touchInit();
+    return touch_value;
+}
 
-#if CONFIG_IDF_TARGET_ESP32
-    uint32_t v0 = READ_PERI_REG(SENS_SAR_TOUCH_ENABLE_REG);
-    //Disable Intr & enable touch pad
-    WRITE_PERI_REG(SENS_SAR_TOUCH_ENABLE_REG,
-            (v0 & ~((1 << (pad + SENS_TOUCH_PAD_OUTEN2_S)) | (1 << (pad + SENS_TOUCH_PAD_OUTEN1_S))))
-            | (1 << (pad + SENS_TOUCH_PAD_WORKEN_S)));
+static void __touchConfigInterrupt(uint8_t pin, void (*userFunc)(void), void *Args, touch_value_t threshold, bool callWithArgs)
+{
+    int8_t pad = digitalPinToTouchChannel(pin);
+    if(pad < 0){
+        return;
+    }
 
-    SET_PERI_REG_MASK(SENS_SAR_TOUCH_ENABLE_REG, (1 << (pad + SENS_TOUCH_PAD_WORKEN_S)));
+    if (userFunc == NULL) {
+        // dettach ISR User Call
+        __touchInterruptHandlers[pad].fn = NULL;
+        threshold = SOC_TOUCH_PAD_THRESHOLD_MAX;   // deactivate the ISR with SOC_TOUCH_PAD_THRESHOLD_MAX
+    } else {
+        // attach ISR User Call
+        __touchInit();
+        __touchInterruptHandlers[pad].fn = userFunc;
+        __touchInterruptHandlers[pad].callWithArgs = callWithArgs;
+        __touchInterruptHandlers[pad].arg = Args;
+    }
 
-    uint32_t rtc_tio_reg = RTC_IO_TOUCH_PAD0_REG + pad * 4;
-    WRITE_PERI_REG(rtc_tio_reg, (READ_PERI_REG(rtc_tio_reg)
-                      & ~(RTC_IO_TOUCH_PAD0_DAC_M))
-                      | (7 << RTC_IO_TOUCH_PAD0_DAC_S)//Touch Set Slope
-                      | RTC_IO_TOUCH_PAD0_TIE_OPT_M   //Enable Tie,Init Level
-                      | RTC_IO_TOUCH_PAD0_START_M     //Enable Touch Pad IO
-                      | RTC_IO_TOUCH_PAD0_XPD_M);     //Enable Touch Pad Power on
+#if SOC_TOUCH_VERSION_1                         // ESP32
+    touch_pad_config(pad, threshold);
+#elif SOC_TOUCH_VERSION_2                       // ESP32S2, ESP32S3
+    touch_pad_set_thresh(pad, threshold);
+#endif
+}
 
-    //force oneTime test start
-    SET_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL2_REG, SENS_TOUCH_START_EN_M|SENS_TOUCH_START_FORCE_M);
+// it keeps backwards compatibility
+static void __touchAttachInterrupt(uint8_t pin, void (*userFunc)(void), touch_value_t threshold)
+{
+    __touchConfigInterrupt(pin, userFunc, NULL, threshold, false);
+}
 
-    SET_PERI_REG_BITS(SENS_SAR_TOUCH_CTRL1_REG, SENS_TOUCH_XPD_WAIT, 10, SENS_TOUCH_XPD_WAIT_S);
+// new additional version of the API with User Args
+static void __touchAttachArgsInterrupt(uint8_t pin, void (*userFunc)(void), void *args, touch_value_t threshold)
+{
+    __touchConfigInterrupt(pin, userFunc, args, threshold, true);
+}
 
-    while (GET_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL2_REG, SENS_TOUCH_MEAS_DONE) == 0) {};
+// new additional API to dettach touch ISR
+static void __touchDettachInterrupt(uint8_t pin)
+{
+    __touchConfigInterrupt(pin, NULL, NULL, 0, false);  // userFunc as NULL acts as dettaching 
+}
 
-    uint16_t touch_value = READ_PERI_REG(SENS_SAR_TOUCH_OUT1_REG + (pad / 2) * 4) >> ((pad & 1) ? SENS_TOUCH_MEAS_OUT1_S : SENS_TOUCH_MEAS_OUT0_S);
 
-    //clear touch force ,select the Touch mode is Timer
-    CLEAR_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL2_REG, SENS_TOUCH_START_EN_M|SENS_TOUCH_START_FORCE_M);
+/*
+    External Public Touch API Functions
+*/
 
-    //restore previous value
-    WRITE_PERI_REG(SENS_SAR_TOUCH_ENABLE_REG, v0);
-    return touch_value;
-#else
-    static uint32_t chan_mask = 0;
-    uint32_t value = 0;
-    if((chan_mask & (1 << pad)) == 0){
-        if(touch_pad_set_thresh((touch_pad_t)pad, TOUCH_PAD_THRESHOLD_MAX) != ESP_OK){
-        	log_e("touch_pad_set_thresh failed");
-        } else if(touch_pad_config((touch_pad_t)pad) != ESP_OK){
-        	log_e("touch_pad_config failed");
-        } else {
-        	chan_mask |= (1 << pad);
-        }
-    }
-    if((chan_mask & (1 << pad)) != 0) {
-        if(touch_pad_read_raw_data((touch_pad_t)pad, &value) != ESP_OK){
-        	log_e("touch_pad_read_raw_data failed");
-        }
+#if SOC_TOUCH_VERSION_1        // Only for ESP32 SoC
+void touchInterruptSetThresholdDirection(bool mustbeLower) {
+    if (mustbeLower) {
+        touch_pad_set_trigger_mode(TOUCH_TRIGGER_BELOW);
+    } else {
+        touch_pad_set_trigger_mode(TOUCH_TRIGGER_ABOVE);
     }
-    return value;
-#endif
 }
-
-void __touchAttachInterrupt(uint8_t pin, void (*userFunc)(void), uint16_t threshold)
-{
+#elif SOC_TOUCH_VERSION_2     // Only for ESP32S2 and ESP32S3
+// returns true if touch pad has been and continues pressed and false otherwise 
+bool touchInterruptGetLastStatus(uint8_t pin) {
     int8_t pad = digitalPinToTouchChannel(pin);
     if(pad < 0){
-        return;
+        return false;
     }
 
-    pinMode(pin, ANALOG);
-
-    __touchInit();
-
-    __touchInterruptHandlers[pad] = userFunc;
-
-#if CONFIG_IDF_TARGET_ESP32
-    //clear touch force ,select the Touch mode is Timer
-    CLEAR_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL2_REG, SENS_TOUCH_START_EN_M|SENS_TOUCH_START_FORCE_M);
-
-    //interrupt when touch value < threshold
-    CLEAR_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL1_REG, SENS_TOUCH_OUT_SEL);
-    //Intr will give ,when SET0 < threshold
-    SET_PERI_REG_MASK(SENS_SAR_TOUCH_CTRL1_REG, SENS_TOUCH_OUT_1EN);
-    //Enable Rtc Touch Module Intr,the Interrupt need Rtc out  Enable
-    SET_PERI_REG_MASK(RTC_CNTL_INT_ENA_REG, RTC_CNTL_TOUCH_INT_ENA);
-
-    //set threshold
-    uint8_t shift = (pad & 1) ? SENS_TOUCH_OUT_TH1_S : SENS_TOUCH_OUT_TH0_S;
-    SET_PERI_REG_BITS((SENS_SAR_TOUCH_THRES1_REG + (pad / 2) * 4), SENS_TOUCH_OUT_TH0, threshold, shift);
-
-    uint32_t rtc_tio_reg = RTC_IO_TOUCH_PAD0_REG + pad * 4;
-    WRITE_PERI_REG(rtc_tio_reg, (READ_PERI_REG(rtc_tio_reg)
-                      & ~(RTC_IO_TOUCH_PAD0_DAC_M))
-                      | (7 << RTC_IO_TOUCH_PAD0_DAC_S)//Touch Set Slope
-                      | RTC_IO_TOUCH_PAD0_TIE_OPT_M   //Enable Tie,Init Level
-                      | RTC_IO_TOUCH_PAD0_START_M     //Enable Touch Pad IO
-                      | RTC_IO_TOUCH_PAD0_XPD_M);     //Enable Touch Pad Power on
-
-    //Enable Digital rtc control :work mode and out mode
-    SET_PERI_REG_MASK(SENS_SAR_TOUCH_ENABLE_REG,
-                      (1 << (pad + SENS_TOUCH_PAD_WORKEN_S)) | \
-                      (1 << (pad + SENS_TOUCH_PAD_OUTEN2_S)) | \
-                      (1 << (pad + SENS_TOUCH_PAD_OUTEN1_S)));
-#else
-
-#endif
+    return __touchInterruptHandlers[pad].lastStatusIsPressed;
 }
-
-extern uint16_t touchRead(uint8_t pin) __attribute__ ((weak, alias("__touchRead")));
-extern void touchAttachInterrupt(uint8_t pin, void (*userFunc)(void), uint16_t threshold) __attribute__ ((weak, alias("__touchAttachInterrupt")));
-extern void touchSetCycles(uint16_t measure, uint16_t sleep) __attribute__ ((weak, alias("__touchSetCycles")));
 #endif
+
+extern touch_value_t touchRead(uint8_t) __attribute__ ((weak, alias("__touchRead")));
+extern void touchAttachInterrupt(uint8_t, voidFuncPtr, touch_value_t) __attribute__ ((weak, alias("__touchAttachInterrupt")));
+extern void touchAttachInterruptArg(uint8_t, voidArgFuncPtr, void *, touch_value_t) __attribute__ ((weak, alias("__touchAttachArgsInterrupt")));
+extern void touchDetachInterrupt(uint8_t) __attribute__ ((weak, alias("__touchDettachInterrupt")));
+extern void touchSetCycles(uint16_t, uint16_t) __attribute__ ((weak, alias("__touchSetCycles")));
+
+#endif      // #if SOC_TOUCH_SENSOR_NUM > 0

cores/esp32/esp32-hal-touch.h

@@ -24,8 +24,21 @@
 extern "C" {
 #endif
 
+#include "soc/soc_caps.h"
 #include "esp32-hal.h"
 
+#if SOC_TOUCH_SENSOR_NUM > 0
+
+#if !defined(SOC_TOUCH_VERSION_1) && !defined(SOC_TOUCH_VERSION_2)
+#error Touch IDF driver Not supported!
+#endif
+
+#if SOC_TOUCH_VERSION_1 // ESP32
+typedef uint16_t touch_value_t;
+#elif SOC_TOUCH_VERSION_2 // ESP32S2 ESP32S3
+typedef uint32_t touch_value_t;
+#endif
+
 /*
  * Set cycles that measurement operation takes
  * The result from touchRead, threshold and detection
@@ -40,17 +53,44 @@ void touchSetCycles(uint16_t measure, uint16_t sleep);
  * You can use this method to chose a good threshold value
  * to use as value for touchAttachInterrupt
  * */
-uint16_t touchRead(uint8_t pin);
+touch_value_t touchRead(uint8_t pin);
 
 /*
- * Set function to be called if touch pad value falls
- * below the given threshold. Use touchRead to determine
- * a proper threshold between touched and untouched state
+ * Set function to be called if touch pad value falls (ESP32)
+ * below the given threshold / rises (ESP32-S2/S3) by given increment (threshold). 
+ * Use touchRead to determine a proper threshold between touched and untouched state
  * */
-void touchAttachInterrupt(uint8_t pin, void (*userFunc)(void), uint16_t threshold);
+void touchAttachInterrupt(uint8_t pin, void (*userFunc)(void), touch_value_t threshold);
+void touchAttachInterruptArg(uint8_t pin, void (*userFunc)(void*), void *arg, touch_value_t threshold);
+void touchDetachInterrupt(uint8_t pin);
+
+/*
+ * Specific functions to ESP32 
+ * Tells the driver if it shall activate the ISR if the sensor is Lower or Higher than the Threshold
+ * Default if Lower.
+ **/
+
+#if SOC_TOUCH_VERSION_1     // Only for ESP32 SoC
+void touchInterruptSetThresholdDirection(bool mustbeLower);
+#endif
+
+
+/*
+ * Specific functions to ESP32-S2 and ESP32-S3
+ * Returns true when the latest ISR status for the Touchpad is that it is touched (Active)
+ * and false when the Touchpad is untoouched (Inactive)
+ * This function can be used in conjunction with ISR User callback in order to take action 
+ * as soon as the touchpad is touched and/or released
+ **/
+
+#if SOC_TOUCH_VERSION_2     // Only for ESP32S2 and ESP32S3
+// returns true if touch pad has been and continues pressed and false otherwise 
+bool touchInterruptGetLastStatus(uint8_t pin);
+#endif
+
+#endif // SOC_TOUCH_SENSOR_NUM > 0
 
 #ifdef __cplusplus
 }
 #endif
-
 #endif /* MAIN_ESP32_HAL_TOUCH_H_ */

libraries/ESP32/examples/Touch/TouchButton/TouchButton.ino

+/*
+
+This is an example how to use Touch Intrrerupts
+The sketh will tell when it is touched and then relesased as like a push-button
+
+This method based on touchInterruptSetThresholdDirection() is only available for ESP32
+*/
+
+#include "Arduino.h"
+
+int threshold = 40;
+bool touchActive = false;
+bool lastTouchActive = false;
+bool testingLower = true;
+
+void gotTouchEvent(){
+  if (lastTouchActive != testingLower) {
+    touchActive = !touchActive;
+    testingLower = !testingLower;
+    // Touch ISR will be inverted: Lower <--> Higher than the Threshold after ISR event is noticed
+    touchInterruptSetThresholdDirection(testingLower);
+  }
+}
+
+void setup() {
+  Serial.begin(115200);
+  delay(1000); // give me time to bring up serial monitor
+  Serial.println("ESP32 Touch Interrupt Test");
+  touchAttachInterrupt(T2, gotTouchEvent, threshold);
+
+  // Touch ISR will be activated when touchRead is lower than the Threshold
+  touchInterruptSetThresholdDirection(testingLower);
+}
+
+void loop(){
+  if(lastTouchActive != touchActive){
+    lastTouchActive = touchActive;
+    if (touchActive) {
+      Serial.println("  ---- Touch was Pressed");
+    } else {
+      Serial.println("  ---- Touch was Released");
+    }
+  }
+  Serial.printf("T2 pin2 = %d \n", touchRead(T2));
+  delay(125);
+}

libraries/ESP32/examples/Touch/TouchButtonV2/TouchButtonV2.ino

+/*
+
+This is an example how to use Touch Intrrerupts
+The sketh will tell when it is touched and then relesased as like a push-button
+
+This method based on touchInterruptGetLastStatus() is only available for ESP32 S2 and S3
+*/
+
+#include "Arduino.h"
+
+int threshold = 1500;   // ESP32S2 
+bool touch1detected = false;
+bool touch2detected = false;
+
+void gotTouch1() {
+  touch1detected = true;
+}
+
+void gotTouch2() {
+  touch2detected = true;
+}
+
+void setup() {
+  Serial.begin(115200);
+  delay(1000); // give me time to bring up serial monitor
+
+  Serial.println("\n ESP32 Touch Interrupt Test\n");
+  touchAttachInterrupt(T1, gotTouch1, threshold); 
+  touchAttachInterrupt(T2, gotTouch2, threshold);
+}
+
+void loop() {
+  static uint32_t count = 0;
+
+  if (touch1detected) {
+    touch1detected = false;
+    if (touchInterruptGetLastStatus(T1)) {
+        Serial.println(" --- T1 Touched");
+    } else {
+        Serial.println(" --- T1 Released");
+    }
+  }
+  if (touch2detected) {
+    touch2detected = false;
+    if (touchInterruptGetLastStatus(T2)) {
+        Serial.println(" --- T2 Touched");
+    } else {
+        Serial.println(" --- T2 Released");
+    }
+  }
+
+  delay(80);
+}