main.cpp

/* Touch Pad Interrupt Example

   This example code is in the Public Domain (or CC0 licensed, at your option.)

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/
#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"

#include "driver/touch_pad.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/sens_reg.h"

static const char* TAG = "Touch pad";
#define TOUCH_THRESH_NO_USE   (0)
#define TOUCHPAD_FILTER_TOUCH_PERIOD (10)

static bool s_pad_activated[TOUCH_PAD_MAX];
static uint32_t s_pad_init_val[TOUCH_PAD_MAX];

volatile uint16_t isrMask=0;

#define TOUCH_PAD_MAX 4

static void tp_example_read_task(void *pvParameter)
{
    int show_message=1;
    touch_trigger_mode_t triggerMode;

    while (1) {
            //interrupt mode, enable touch interrupt
            touch_pad_intr_enable();
            
			
			if (isrMask!=0){
            	ESP_LOGI(TAG, "Bit mask from ISR: %#x",isrMask );
            	

            }
		isrMask=0;

           /* for (int i = 2; i < TOUCH_PAD_MAX; i++) {
                if (s_pad_activated[i] == true) {
                    ESP_LOGI(TAG, "T%d activated!", i);
                    // Wait a while for the pad being released
                    vTaskDelay(20 / portTICK_PERIOD_MS);
                    // Clear information on pad activation
                    s_pad_activated[i] = false;
                    // Reset the counter triggering a message
                    // that application is running
                }
            }
        */

        vTaskDelay(10 / portTICK_PERIOD_MS);

        // If no pad is touched, every couple of seconds, show a message
        // that application is running
        if (show_message++ % 500 == 0) {
        touch_pad_get_trigger_mode(&triggerMode);
        
        if (triggerMode==TOUCH_TRIGGER_BELOW){
            ESP_LOGI(TAG, "Switching trigger mode to ABOVE");
            
            touch_pad_set_trigger_mode(TOUCH_TRIGGER_ABOVE);
        } else {
        
        	ESP_LOGI(TAG, "Trigger mode is BELOW");
            
            touch_pad_set_trigger_mode(TOUCH_TRIGGER_BELOW);
        }
        }
    }
}

/*
  Handle an interrupt triggered when a pad is touched.
  Recognize what pad has been touched and save it in a table.
 */
static void tp_example_rtc_intr(void * arg)
{
    isrMask = touch_pad_get_status();
    //clear interrupt
    touch_pad_clear_status();

}

void app_main()
{
    // Initialize touch pad peripheral, it will start a timer to run a filter
    ESP_LOGI(TAG, "Initializing touch pad");
    touch_pad_init();

    // If use interrupt trigger mode, should set touch sensor FSM mode at 'TOUCH_FSM_MODE_TIMER'.
    touch_pad_set_fsm_mode(TOUCH_FSM_MODE_TIMER);
    
    touch_pad_set_trigger_mode(TOUCH_TRIGGER_BELOW);
    
    // Set reference voltage for charging/discharging
    // For most usage scenarios, we recommend using the following combination:
    // the high reference valtage will be 2.7V - 1V = 1.7V, The low reference voltage will be 0.5V.
    touch_pad_set_voltage(TOUCH_HVOLT_2V7, TOUCH_LVOLT_0V5, TOUCH_HVOLT_ATTEN_1V);
    // Init touch pad IO
    
    for (int i = 2;i< TOUCH_PAD_MAX;i++) {
        //init RTC IO and mode for touch pad.
        touch_pad_config(i, TOUCH_THRESH_NO_USE);
    }
    
    // Set thresh hold
 uint16_t touch_value;
    for (int i = 2; i<TOUCH_PAD_MAX; i++) {
        //read filtered value
        touch_pad_read(i, &touch_value);
        s_pad_init_val[i] = touch_value;
        ESP_LOGI(TAG, "test init: touch pad [%d] val is %d", i, touch_value);
        //set interrupt threshold.
        ESP_ERROR_CHECK(touch_pad_set_thresh(i, touch_value * 0.95));
    }
    
    // Register touch interrupt ISR
    touch_pad_isr_register(tp_example_rtc_intr, NULL);
    // Start a task to show what pads have been touched
    xTaskCreate(&tp_example_read_task, "touch_pad_read_task", 2048, NULL, 5, NULL);
}